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CONFRONTING THE
EARTH’S TRIBULATIONS
David Ritchey Headline Books, Inc. Terra Alta, WV
Confronting the Earth’s Tribulations by David Ritchey ©2019 David Ritchey All rights reserved. No part of this publication may be reproduced or transmitted in any other form or for any means, electronic or mechanical, including photocopy, recording or any information storage system, without written permission from Headline Books, Inc. To order additional copies of this book or for book publishing information, or to contact the author: Headline Books, Inc. P. O. Box 52 Terra Alta, WV 26764 www.headlinebooks.com Tel: 304-789-3001 Email: mybook@headlinebooks.com ISBN: 9781946664617 Library of Congress Control Number: 2019902706
P R I N T E D I N T H E U N I T E D S T AT E S O F A M E R I C A
To all those who give of themselves to heal the Planet Earth.
With thanks to my friends and colleagues Ellen Meyer and Cornelia Keener for their ongoing support and superb editing assistance
Contents Preface.......................................................................... vii Section I: Cosmic Billiards Chapter 1: When Spacetime Began...........................11 Chapter 2: Earth’s Collisions Billions of Years Ago..............................................17 Chapter 3: Earth’s Collisions Millions of Years Ago.............................................20 Chapter 4: Earth’s Collisions Thousands of Years Ago.........................................23 Chapter 5: Earth’s Collisions in the Holocene Epoch............................................25 Chapter 6: Predicting Earth’s Astronomical Collisions.........................................35 Section II: The Last Ice Age Introduction................................................................45 Chapter 7: Ice Ages in General..................................47 Chapter 8: The Most Recent Glacial Period..............56 Chapter 9: Humans and Other Critters.......................64 Section III: When The Earth Shudders Introduction................................................................84 Chapter 10: Earthquakes in General .........................86 Chapter 11: Selected Earthquakes Prior to 1900.....100 Chapter 12: Selected Twentieth Century Earthquakes...........................................................116 Chapter 13: Selected Twenty-First Century Earthquakes...........................................................137 Chapter 14: What’s Next?........................................150 Appendix A: Comparative Data – Selected Earthquakes.........................................165
Section IV: Big Waters Rolling Chapter 15: Floods in General.................................168 Chapter 16: The Worst Riverine Floods in World History........................................176 Chapter 17: The Worst Riverine Floods in US History............................................187 Chapter 18: Hurricane- and Tsunami-Related Floods.......................................199 Chapter 19: Dealing With Floods............................233 Chapter 20: Global Climate Change and Flooding.........................................................239 Section V: Infernal Wildfires Chapter 21: Wildfires in General.............................245 Chapter 22: Wildfire Prevention .............................253 Chapter 23: Wildfire Suppression............................257 Chapter 24: Specific Noteworthy Wildfires.............261 Chapter 25: Future Wildfires....................................275 Section VI: Killing Her Slowly Introduction..............................................................283 Chapter 26: Pollution in General.............................285 Chapter 27: Energy Pollution...................................292 Chapter 28: Air Pollution.........................................299 Chapter 29: Land Pollution .....................................307 Chapter 30: Water Pollution.....................................321 Chapter 31: Environmentalism................................335 Index...........................................................................345 Books by David Ritchey.............................................349 About the Author.........................................................352
Preface Since the beginning of its existence, the Earth has been subjected to countless trials and tribulations. The planet was formed in an environment of chaos and destruction involving astronomical collisions, earthquakes, and volcanic eruptions. Since taking shape, the Earth’s mettle has been tested again and again by these forces as well as ice ages, blizzards, floods and tsunamis, cyclones, wildfires, man-made pollution, and human-caused climate change. I find these subjects to be very interesting, and have already written about some of them, namely volcanic eruptions (Pyramids of Fire – 2016), cyclones (A Brief History of Hurricanes – 2017), and blizzards (Up to the Eaves – 2018). When I began to explore the possibilities inherent in writing about some other challenges that have been met by the planet Earth, I decided on six subjects which I have organized into sections herein, namely: Cosmic Billiards (about astronomical collisions), The Last Ice Age (about ice ages), When the Earth Shudders (about earthquakes), Big Waters Rolling (about floods and tsunamis), Infernal Wildfires (about wildfires), and Killing Her Slowly (about pollution). I would like to extend my thanks to my friend and colleague, Ellen Meyer, for her ongoing support and superb editing assistance. vii
Section I
Cosmic Billiards Earth’s Astronomical Collisions
Chapter 1
When Spacetime Began It all began with the “Big Bang,” an event that occurred about 13.8 billion years ago at an extremely high-density and high-temperature location in which there was a gravitational singularity—a location in spacetime where the gravitational field of a celestial body becomes infinite in a way that does not depend on the coordinate system, and the laws of normal spacetime cannot exist. It wasn’t an explosion of matter in space that moved outward to fill an empty universe; it was, rather, an expansion of space and time everywhere, increasing the physical distance between two co-moving points. Over a long period of time, the slightly denser regions of the nearly uniformly distributed matter gravitationally attracted nearby matter and thus grew even denser, forming gas clouds, stars, galaxies, and the other astronomical structures observable today. The first galaxies took shape as little as one billion years after the Big Bang. The galaxy-formation process has not stopped as our universe continues to evolve. The galaxies themselves merge together fairly often because the universe is a crowded place on the galactic distance scale. The formation and evolution of our solar system began 4.6 billion years ago with the gravitational 11
collapse of a small part of the universe’s giant molecular cloud. Most of the collapsing mass collected near the center, forming the sun, while the rest flattened into a protoplanetary disk out of which the planets, moons, asteroids, and other small solar system bodies formed. These astronomical entities formed by accretion of dust grains in orbit around the central protostar. The solar system has continued to evolve considerably since its initial formation. Many moons have formed from discs of gas and dust circling around their parent planets, while other moons formed independently and later were captured by their planets. Moons of solid solar system bodies have been created by both collisions and capture. The Earth’s moon is thought to have formed as a result of a single giant impact collision of the Earth with another planet-sized body. The inner solar system was too hot for volatile molecules like water and methane to condense, so the planetesimals that formed there could only assemble from compounds with high melting points, such as metals (like iron, nickel, and aluminum) and rocky silicates. These rocky bodies would eventually become the terrestrial planets (Mercury, Venus, Earth, and Mars). The compounds that formed them are quite rare in the universe, comprising only 0.6% of the mass of the nebula, so the terrestrial planets could not grow very large by accretion. The terrestrial embryos grew only to about 0.05 Earth masses and ceased accreting matter Terrestrial Planets about 100,000 years after the formation of the sun. 12
However, subsequent collisions and mergers between these planet-sized bodies, over a period of about 100 million years, allowed terrestrial planets to grow to their present sizes. Earth, along with our solar system, is situated in the Milky Way galaxy about 28,000 light-years from its center. The Earth was formed about 4.54 billion years ago. It is the third planet from the sun, the densest planet in the solar system, the largest of the four terrestrial planets, and the only object in the universe known to harbor life. The Earth orbits the sun at an average distance of about 93 million miles every 365.2564 mean solar days (one sidereal year). The orbital speed of Earth averages about 66,600 miles per hour. On average, it takes 24 hours—a solar day—for Earth to complete a full rotation on its axis. From an astronomical distance perspective, the universe is a crowded place, and astronomical bodies frequently collide with one another. These collisions, or “impact events,” have physical consequences and have been found to regularly occur in planetary systems, although they most frequently involve asteroids, comets, or meteoroids and have minimal effect. When large objects impact terrestrial planets such as the Earth, however, there can be significant physical and biospheric repercussions. Major impact events have significantly shaped Earth’s history, and they have been involved in the formation of the Earth–moon system, the origin of water on Earth, and several mass extinctions. Impact events early in the history of Earth have been credited with creative as well as destructive events; it has been proposed that impacting comets delivered the Earth’s water, and some scientists have suggested that the origins of life may have been influenced by impacting objects 13
bringing organic chemicals or life forms to the Earth’s surface. Astronomical objects that collide with the Earth include: • Comets: Celestial bodies moving around the sun, usually in a highly eccentric orbit, consisting of a central mass surrounded by an envelope of dust and gas that may form a tail that streams away from the sun.
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•
Asteroids: Any of the thousands of small astronomical bodies—with diameters from 480 miles to less than 1 mile—that revolve around the sun in orbits mostly between those of Mars and Jupiter. Asteroids are generally made up of metals and rocky material, while comets are made up of ice, dust, and rocky material.
•
Meteoroids: Any of the small bodies, often remnants of comets, traveling through space; when such a body enters the Earth’s atmosphere, it is heated to luminosity and becomes a meteor. Meteoroids are significantly smaller than asteroids, and range in size from small grains to 1-meter-wide objects. Objects smaller than the smallest meteroids are classified as micrometeoroids or space dust.
•
Meteors: Meteoroids that have entered the Earth’s atmosphere and manifest as transient fiery streaks in the sky; also called shooting stars or bolides.
•
Meteorites: Masses of stone or metal that withstand ablation from passage through the atmosphere as a meteor and impacts with the ground. An estimated 15,000 tons of meteoroids, micrometeoroids, and different forms of space dust enter Earth’s atmosphere each year.
These impact-related views of Earth’s history did not emerge until relatively recently. The main reasons for this include: lack of direct observations; the difficulty of recognizing the signs of an Earth impact because of erosion and weathering; and that large-scale terrestrial impacts are rare. Instead, it was widely believed that cratering was the result of volcanism, and the craters on the surface of the moon were likewise ascribed to volcanism. It was not until 1903–1905, for example, that the Barringer Crater in Arizona was correctly identified as an impact crater, and it was not until 1963 that this hypothesis was conclusively proven. The findings of late 20th-century space exploration demonstrated that impact cratering was by far the most widespread geological process at work on the solar system’s solid bodies. Every surveyed solid body in the solar system was found to be cratered, and there was no reason to believe that the Earth had somehow escaped bombardment from space. Two major creative processes that have generally been traced to Earth’s collisions are the origin of water and the development of life on the planet. With respect to water: Some scientists believe that water stored in hydrate minerals was present on Earth since the beginning, and, with outgassing and volcanic activity, the oceans and atmosphere would have started to develop even as the Earth formed; others assert that water is too volatile to have been present at Earth’s formation and must have been delivered much later from outer, colder parts of the solar system by way of asteroids, comets, and meteoroids through a process known as “impact degassing” in which incoming bodies vaporize on impact. With respect to life: Evidence suggests life emerged prior to 3.8 billion years ago. Biologists reason that all living organisms on Earth must share a single last universal common ancestor, because it would be 15
virtually impossible for two or more separate lineages to independently develop the many complex biochemical mechanisms common to all living organisms. While some scientists believe that life might have emerged from non-living chemicals by a process not yet known, others adhere to the Panspermia hypothesis, which holds that life exists throughout the universe, and is distributed by space dust, meteoroids, asteroids, comets, planetoids, and also, perhaps, by spacecraft from elsewhere carrying unintended contamination by microorganisms. The hypothesis does not explain how life arose in the first place, but simply examines the possibility that it came from somewhere other than Earth. Theoretically, certain types of microscopic life forms able to survive the effects of space travel can become trapped in debris ejected into space after collisions between planets and small solar system bodies that harbor life. Under certain ideal impact circumstances (into a body of water, for example) and ideal conditions on a new planet’s surfaces, it is possible that the surviving organisms could become active and begin to colonize their new environment.
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Chapter 2
Earth’s Collisions Billions of Years Ago Our solar system was formed about 4.6 billion years ago, and the Earth was formed about 4.5 billion years ago. In the ensuing eons, the Earth has been subjected to countless collisions with other celestial bodies. The largest and the most frequent of these collisions presumably occurred when the Earth was still very young. According to the Giant Impact Hypothesis, the granddaddy of them all took place about 4.4 billion years ago when an astronomical body about the size of Mars collided with Earth. According to the hypothesis, that’s when the moon was formed. During the Earth’s formation, it probably experienced multiple impacts from very large bodies, but that one was the last of the “giant impacts.” In the Giant Impact, most of the outer silicates of the colliding body would have been vaporized, whereas its iron core would not. Its core would have sunk into the young Earth’s core, and a portion of its mantle Moon-Forming Giant Impact
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would have accreted onto the Earth’s mantle. However, a significant portion of the mantle material from both bodies would have been ejected into orbit around the Earth. The mantle material orbiting around the Earth would have quickly coalesced gravitationally into a single spherical object—the moon—possibly within less than a month, but definitely in no more than a century. Given that most of the collisional material sent into orbit would have consisted of mantle silicates, the newly formed moon would have been deficient in iron. Indeed, current research shows that while the moon has the same composition as the Earth’s crust, its iron core is less than about 25% of its radius, in contrast to about 50% for most of the other terrestrial bodies. It is noteworthy that the Earth has the highest density of all the planets in the solar system. Current evidence supporting the Giant Impact Hypothesis includes: • Earth’s spin and the moon’s orbit have similar orientations; •
Moon samples indicate that the moon’s surface was once molten;
•
The moon has a relatively small iron core;
•
The moon has a much lower density than Earth;
•
The stable-isotope ratios of lunar and terrestrial rock are identical, implying a common origin.
In the early history of the Earth, collisions among astronomical bodies were almost certainly commonplace, since the solar system then contained far more discrete bodies than it does now. The period from approximately 4.1 to 3.8 billion years ago—after the Earth had formed and accreted most of its mass, but still quite early in its history—is known as the Late Heavy Bombardment. During that time frame, an enormous number of 18
astronomical bodies collided with the Earth. While they were smaller than the colliding body in the Giant Impact, many were still very large—hundreds of miles in diameter—with explosions so powerful that they could have vaporized all of Earth’s oceans. It was not until this heavy bombardment slackened that life began to evolve on Earth. It has been estimated that the number of impact craters formed on Earth at that time were as follows: • 22,000+ impact craters with diameters >12 miles; •
about 40 impact basins with diameters of ~620 miles;
•
several impact basins with diameters of ~3,100 miles.
Because of aging, erosion, and vegetation growth, most of these craters are not visible and have yet to be found.
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Chapter 3
Earth’ Collisions Millions of Years Ago Despite the fact that craters formed millions—rather than billions—of years ago are still difficult to locate, when they are discovered, they sometimes can yield a bit more information about the impacting body and its consequences than the older ones. Animal life on Earth evolved during this time period, especially during the Cambrian Explosion about 541 million years ago; and research has shown that a number of mass extinctions occurred. While the causes and factors involved in mass extinctions are still not well understood, the consensus is that at least one impact (and possibly several more), the Chicxulub Impact of 66 million years ago (discussed below), was responsible. The Warburton Basin in South Australia is the site of two large-impact craters from around 360-300 million years ago that created a 250-mile impact zone, the largest ever recorded. The subterranean structures lie buried under the surface at a depth of approximately 2.5 miles. It has been theorized that the original size of the incoming asteroid was about 12 miles across, and just before impacting, it split into two pieces, each about 6 20
miles across. The impact from an asteroid that size could have been great enough to create a mass extinction event at that time, but no evidence of such an extinction has yet been found. The Chicxulub Crater is an impact crater, roughly 93 miles in diameter and 12 miles in depth, buried underneath the Yucatán Peninsula in Mexico. It was formed by a large asteroid or comet about 6 to 9 miles in diameter, the Chicxulub Impactor, which struck the Earth about 66 million years ago during the Cretaceous–Paleogene extinction event. The energy released upon impact has been estimated to be equivalent to 100 teratons of TNT (a teraton equals 1 million megatons). That is roughly 10 billion times stronger than the bomb dropped on Hiroshima (~15 kilotons), and the most energetic event in the history of Earth for hundreds of millions of years. That is far more powerful than any volcanic eruption, earthquake, or firestorm, and is enough energy to power the entire Earth for several centuries. By contrast, the most powerful nuclear weapon built by humans, the Soviet Union’s Tsar Bomba, had a yield of only 50 megatons (~.005% of Chicxulub). The impact would have caused a megatsunami over 300 feet tall, the height of which would have been limited by the relatively shallow sea in the area of the impact; in deep ocean, it would have been 2.9 miles tall. A cloud of super-heated dust, ash, and steam—along with pieces of the impactor—would have been ejected from the crater into the atmosphere. They would have been heated to incandescence upon re-entry, broiling the Earth’s surface and possibly igniting wildfires. Meanwhile, colossal shock waves would have triggered global earthquakes and volcanic eruptions. The emission of gases and particles would have led to a sudden greenhouse effect, wherein the blocking of sunlight would have cooled the Earth’s 21
atmosphere significantly, and photosynthesis by plants would have been interrupted, affecting the entire food chain. These events then resulted in a mass extinction in which 76% of plant and animal species on Earth became extinct. With only a few exceptions, no large tetrapods survived, and all non-avian dinosaurs became extinct, paving the way for the evolution of mammals on land and sharks in the sea. Mistastin Crater is a meteorite crater in Labrador, Canada, that was created approximately 36 million years ago by a violent asteroid impact. The estimated diameter of the original crater is 17 miles. The crater contains the roughly circular Mistastin Lake, which is approximately 9.9 miles in diameter. The presence of cubic zirconia around the crater rim suggests that the impact generated temperatures in excess of 4,300 °F (half that of the surface of the sun), the highest crustal temperatures known to ever have occurred on Earth, and produced global changes that lasted for decades after the impact. The Eltanin Impact is thought to have been an asteroid impact in the eastern part of the South Pacific Ocean about 2.5 million years ago. Its location was at the edge of the Bellingshausen Sea, 930 miles southwest of Chile and near Antarctica. The event is thought to have involved an object about 1–2.5 miles in diameter that was traveling at a speed of 45,000 miles per hour. The strike would have caused a tsunami over 660 feet high and left a crater approximately 20 miles across. The impact zone was first discovered in 1981 as an iridium anomaly in the sediment.
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Chapter 4
Earth’s Collisions Thousands of Years Ago Impact craters formed thousands of years ago are generally more visible than those formed millions or billions of years ago because they have not been subjected to erosion, burial, and other natural processes over such extended periods of time. Some are, in fact, quite obvious. Lonar Crater in India was created by the impact of a celestial body usually estimated to have occurred about 50,000 years ago, but some estimates suggest it may be much older. The crater, which is about 6,000 feet in diameter and 500 feet deep, contains a saline soda lake about 4,000 feet in diameter that is located about 450 feet below the crater rim. The crater rim rises roughly 65 feet above the surrounding land surfaces. Lonar is the only known hyper-velocity impact crater in basaltic rock anywhere on Earth. Lonar Crater It was initially believed to be of volcanic origin, but now it is definitively recognized as an impact crater. 23
Barringer Crater (locally known as “Meteor Crater”) is an impact crater located in the northern Arizona desert that was created about 50,000 years ago. It lies at an elevation of about 5,700 feet above sea level, is approximately 3,900 feet in diameter and 560 feet deep, and is surrounded by a rim that rises about 150 feet above the surrounding plains. The center of the crater is filled with about 750 feet of rubble lying Barringer Crater above crater bedrock. The object that created the crater was a nickeliron meteorite about 160 feet across and weighing approximately 300,000 tons. The speed of the impact has been a subject of some debate, with estimates ranging from 28,800 miles per hour to 43,200 miles per hour. It is believed that about half of the impactor’s mass was vaporized during its descent through the atmosphere. Impact energy has been estimated at about 10 megatons. The portion of the meteorite that survived the descent was mostly vaporized upon impact, leaving few remains in the crater. Its massive explosion excavated about 175 million tons of rock. While the impact event was too small to cause global environmental effects, its regional damage would have been significant. Events of this size, which occur about once in 6,000 years, are large enough to destroy a modern city. The relatively young age of Barringer Crater, coupled with the dry Arizona climate, have allowed this crater to remain almost unchanged since its formation. The lack of erosion that preserved the crater’s shape helped lead to its being the first crater recognized as an impact crater from a natural celestial body. 24
Chapter 5
Earth’s Collisions in the Holocene Epoch The Holocene is the current geological epoch. It began approximately 11,650 years ago, after the last glacial period, which concluded with the Holocene glacial retreat. The name Holocene comes from the Ancient Greek in which it means “entirely recent.” The large number of verified celestial body collisions with Earth during this period doesn’t mean that they occurred more often then, but, rather, that those collisions can be accounted for both because the impact sites are still in nearly pristine condition because of their recency and also because humans have been around to observe their occurrence. For many years, people did not know what it was that they were witnessing, but they nevertheless did see streaks of light in the sky, craters, and metallic stones. They also occasionally heard loud noises (sonic booms). Throughout the Renaissance and the early years of modern science, astronomers refused to accept the existence of meteorites. The idea that stones could fall from space was regarded as superstitious and possibly heretical—given that God surely would not have created 25
such an untidy universe. Their position was, “Stones cannot fall from the sky, because there are no stones in the sky,” and the concept of meteorites was dismissed as nothing more than medieval illusions and old wives’ tales. Some “rogue” scientists, however, continued to take the study of meteorites seriously, and by around 1800, scientific views began to change. The Clovis Comet is the first impacting body that I will be discussing here. It is unquestionably the most noteworthy and the earliest of the bunch. The thing is, it may have not have even existed. The existence of the Clovis Comet is a highly controversial subject in the scientific community. The hypothesis was first put forth in 2007 as an explanation for a mass extinction that occurred during the Younger Dryas period of 12,900 to 11,650 years ago—the immediate precursor to the Holocene Era. During the Younger Dryas period, Earth’s temperatures plunged abruptly. This is thought to explain the demise of the Clovis people, the earliest human settlers of North America, as well as the megafauna extinction of the time in which some 35 different mammal species, including the wooly mammoth, were wiped out. According to the theory, a comet, about 1 mile in diameter, exploded just above the Earth’s surface over modern-day Canada approximately 12,900 years ago, sparking a massive shock wave and heatgenerating event that set large parts of the northern hemisphere ablaze. The fact that scientists haven’t found a distinct crater suggests that the comet exploded in the Exploding Comet air rather than directly 26
impacting the Earth, and that the Laurentide ice sheet absorbed much of the force from the explosion. The comet’s explosion would have briefly heated up a large area, causing the Laurentide Ice Sheet to melt and sending massive amounts of fresh water into the Atlantic Ocean, which would then have affected the ocean currents that are ultimately responsible for global temperatures. Additionally, the massive wildfires caused by the comet would have loaded the atmosphere with sun-blocking dust, soot, water vapor, and nitric oxides. These polluting elements would have circled the Earth for a number of years, substantially reducing the amount of sunlight reaching the Earth’s surface, thereby killing off plant life and resulting in the starvation of vast numbers of herbivores and the carnivores who fed upon them. When the atmosphere cleared, temperatures rose dramatically, ushering in the Holocene epoch. In recent years, a number of findings have supported the theory, the most important of them being: • North American soil samples from that era exhibited an unusually high level of iridium—an element more common in extraterrestrial objects than in the Earth’s crust. •
Sediments from six sites across North America yielded large quantities of nanodiamonds (which only occur in sediment exposed to extreme temperatures and pressures, such as those from an explosion or impact). These were conclusively sourced through X-ray diffractometry back to the diamond fields region of Canada. The most plausible scenario for explaining their presence so far south is the kind of cataclysmic explosive event described by the comet impact hypothesis.
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The Kaali Crater field is a group of one large and eight small meteorite craters in Estonia that is believed to have been created by an impact event about 7,500 years ago. It was then and still is one of the few impact events that has occurred in a populated area Before the 1930s, there were several hypotheses about the origin of the craters, including theories involving volcanism and karst processes. Its meteoritic origins were first conclusively demonstrated in 1937. The craters were formed by a meteor with an estimated total mass of 10–20 tons traveling at a speed of approximately 30,000 miles per hour. At an altitude of 3–6 miles, the meteor broke into pieces before making impact with the Earth. The largest fragment produced a crater with a diameter of 360 feet and a depth of 72 feet. Kaali Lake is on the bottom of this crater. Eight smaller craters, all within a half mile of the main crater, were also formed by this bombardment. Their diameters range from 40 to 130 feet, and their depths range from 3 to 13 feet. Campo del Cielo (“Field of Heaven”) is a group of iron meteorites found in Argentina. The crater field covers an area of 1.9 by 11.5 miles and contains at least 26 craters, the largest being 377 by 299 feet. The age of the craters is estimated at 4,000–5,000 years. The iron-mass–containing craters were first reported in 1576, but they were already well known to the aboriginal inhabitants of the area. The craters and the surrounding area contain numerous fragments of an iron meteorite. The largest mass of 40 tons was located using a metal detector in 1969 at a depth 16 feet. That stone, named El Chaco, is the second heaviest single-piece meteorite after the Hoba meteorite (Namibia), which weighs about 65 tons. However, the total mass of the Campo del Cielo fragments found so far exceeds 100 tons, making it the heaviest meteorite ever recovered on Earth. At least 28
two of the craters contained thousands of small iron pieces. Such an unusual distribution suggests that a large celestial body entered the Earth’s atmosphere and broke into pieces before impacting with the ground. The size of the main body is estimated to have been larger than 12 feet in diameter. The Henbury Craters in Australia, which are about 5,000 years old, are the result of one of the few impact events that occurred in a populated area. The crater field contains over a dozen craters, which were formed when a meteorite broke up before impacting with the Earth’s surface. There are 13 to 14 craters ranging from 23 to 591 feet in diameter and up to 49 feet in depth. Several tons of iron-nickel fragments have been recovered from the site. The craters were discovered in 1899, but then went uninvestigated until 1930. Whitecourt Crater in Alberta, Canada, is estimated to have been formed between 1,080 and 1,130 years ago. The crater, which is in a heavily forested area, is approximately 118 feet in diameter and 30 feet deep. It was discovered in 2007, when a metal detector revealed fragments of meteoric iron scattered around the area. More than 3,000 pieces of the impacting meteorite had been found (as of 2012. The pieces are shrapnel—mostly less than 20 ounces in mass with sharp edges—and are mechanically deformed from the impact, but they show no sign of impact melt. About a half-dozen individual meteorites have also been found, with the largest weighing 68 pounds. The Qìngyáng Event that occurred in April 1490 in the Shaanxi district of China is a presumed meteor shower or air burst. A large number of deaths were recorded in historical Chinese accounts of the event, but they have not been confirmed by researchers in the modern era. 29
The historical records describe a shower during which “stones fell like rain,” killing more than 10,000 people. The Tunguska Event was a large-impact event that occurred near the Stony Tunguska River in the Eastern Siberian Taiga region of Russia on the morning of June 30, 1908. The Tunguska Event is the largest impact event on Earth in recorded history. The explosion is generally attributed to the air burst of a meteoroid, and is classified as an impact event—even though no impact crater has been found. The object, estimated to have been 200 feet across, is thought to have disintegrated at an altitude of 3 to 6 miles—instead of hitting the surface of the Earth— and to have had an energy yield of 5–10 megatons of TNT (200 times that of the atomic bomb dropped on Hiroshima). The explosion felled about 80 million trees over an area of approximately 800 square miles in a sparsely populated forest, yet caused no known human casualties. The shock wave from the blast would have measured 5.0 on the Felled Trees – Tunguska Richter earthquake magnitude scale—of sufficient magnitude to destroy a large metropolitan area. Witnesses to the event observed a column of bluish light—nearly as bright as the sun— moving across the sky. About 10 minutes later, there was a flash and a sound similar to artillery fire. The sounds were accompanied by a shock wave that knocked people off their feet and broke windows hundreds of miles away. The majority of witnesses reported only the sounds and tremors, and did not report seeing the explosion. Over the next few days, night skies in Asia and Europe were aglow, and it has been theorized that this effect was due 30
to light passing through high-altitude ice particles that had formed at extremely low temperatures. The Sikhote-Alin Meteorite fell in southeastern Russia on February 12, 1947. Though large iron meteorite falls had been reported previously, and fragments were recovered, never before in recorded history had a fall of this magnitude been actually observed. The overall size of the meteoroid has been estimated at approximately 100 tons, and approximately 80 tons of material survived the fiery passage through the atmosphere and reached the Earth. As the meteor, traveling at a speed of about 30,000 miles per hour, entered the atmosphere, it began to break apart at an altitude of about 3.5 miles, and the fragments fell together. The resultant impact field covered an elliptical area of about 0.5 square miles, and some of the fragments made impact craters, the largest of which was about 85 feet across and 20 feet deep. Eyewitnesses observed a large bolide brighter than the sun. The bright flash and the deafening sound of the fall were observed for 200 miles around the point of impact. A smoke trail, estimated at 20 miles long, remained in the sky for several hours. The Sylacauga Meteorite, which occurred on November 30, 1954, was the first documented extraterrestrial object to have injured a human being. The grapefruit-sized, 9-pound fragment crashed through the roof of a farm house, bounced off a large wooden console radio, and hit a 34-year-old woman while she napped on a couch. She was badly bruised on one side of her body, but was able to walk. Even though it fell early in the afternoon, the meteor made a fireball visible from three states as it streaked through the atmosphere,. There were also indications of an air blast, as witnesses described hearing “explosions or loud booms.” 31
The Příbram Meteorite fell on April 7, 1959, in former Czechoslovakia. At about 8.1 miles high, the meteor, which was estimated to weigh 117 pounds, fragmented, and several pieces came to Earth. Four pieces, with a total weight 12.63 pounds, were recovered, the largest weighing 9.76 pounds. The meteorite was found to have penetrated plowed land to a depth of 8 inches, after which it bounced and fall 12 inches further on. The fall was preceded by a bright bolide, the light of which extended to 30 miles, and was seen throughout western Czechoslovakia. One loud and several quieter explosions were heard. Příbram was the first meteorite whose trajectory was tracked by multiple cameras recording the associated fireball. This allowed its trajectory to be calculated, leading to a determination of its orbit and aiding in its recovery. The Neuschwanstein Meteorite fell to Earth on April 6, 2002, near Neuschwanstein Castle, Bavaria. The original mass of the meteoroid, which entered the atmosphere at 46,900 miles per hour, was estimated at 650 pounds, of which about 45 pounds should have reached the ground. It fragmented at a height of about 14 miles above the ground, and the fragments descended on an area of several square miles. Recovered were three fragments, with a total mass of about 13 pounds, the largest of which weighed 6.3 pounds. Neuschwanstein was the first meteorite in Germany, and the fourth in the world, to be monitored by one of the world’s fireball networks. Photographing the meteor simultaneously from several locations allowed accurate reconstruction of its trajectory and location of its fragments. The Carancas Meteorite was in impact event that occurred in Peru at an altitude of 12,500 feet on September 15, 2007. It involved a meteorite that was at least 10 feet in diameter before breaking up. The 32
impact created a crater more than 43 feet wide and 15 feet deep with visibly scorched earth around its location. When it hit, the meteorite was hotter than most usually are, perhaps because its outer layers didn’t have time to burn off as a result of the high altitude at which the strike occurred. Boiling water, smoke, and fetid noxious gases emerged from the crater, and particles of rock and cinders were found nearby. The meteorite, with a smoky tail, was bright enough to have been seen from 12 miles away, and people reported hearing an explosion— presumably the impact. After the impact, local villagers who had approached the crater became sick from a thenunexplained illness with a wide array of symptoms. The ground water in the local area is known to contain arsenic compounds, and the illness is now believed to have been caused by arsenic poisoning contracted when residents of the area inhaled the vapor of the boiling arsenic-contaminated water. 2008 TC3 was a 90-ton, 13-foot diameter asteroid that entered Earth’s atmosphere at 29,000 miles per hour on October 7, 2008. It exploded at an estimated 23 miles above a remote area of the Nubian Desert in Sudan with the energy of 0.9 to 2.1 kilotons of TNT, causing a large bolide. Some 600 meteorites, weighing a total of 23.1 pounds, were recovered from the impact field. It was the first time that an asteroid impact had been predicted prior to its entry into the atmosphere as a meteor, having been discovered by telescope 19 hours earlier. The Chelyabinsk Meteor was a superbolide caused by an approximately 65-foot near-Earth asteroid with an estimated initial mass of about 13,000–14,000 tons; it entered Earth’s atmosphere over Russia at a speed of about 40,000 miles per hour on February 15, 2013. It quickly became a brilliant superbolidemeteor over the southern Ural region. The object, which was undetected 33
before its atmospheric entry, exploded in an air burst at a height of around 97,000 feet, producing a bright flash, a hot cloud of dust, a large shock wave, and many surviving small fragmentary meteorites. The bulk of the object’s energy was absorbed by the atmosphere, with a total kinetic energy esChelyabinsk Meteor timated to be equivalent to the blast yield of 400–500 kilotons of TNT. When the blast hit the ground, it produced a seismic wave that registered on seismographs at magnitude 2.7. The light from the meteor was brighter than the sun, visible up to 60 miles away, and some eyewitnesses also felt intense heat from the fireball. Its explosion created panic among local residents, and about 1,500 people were injured seriously enough to seek medical treatment. This was the only meteor confirmed to have resulted in a large number of injuries. No deaths were reported. Most of the injured were hurt by the secondary blast effects of shattered, falling, or blown-in glass. The intense light from the meteor, momentarily 30 times brighter than the sun, also produced injuries, leading to over 180 cases of eye pain, and 70 people subsequently reported temporary blindness. Twenty people reported ultraviolet burns similar to sunburn, possibly intensified by the presence of snow on the ground. Some 7,200 buildings in six cities across the region were damaged by the explosion’s shock wave, and damages were about $33 million USD.
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Chapter 6
Predicting Earth’s Astronomical Collisions Small celestial objects enter the Earth’s atmosphere all the time. The vast majority of meteoroids with a diameter of less than 3 feet burn up before they hit the ground as meteorites. An estimated 500 meteorites reach the Earth’s surface each year, but only 5 or 6 of these typically create a weather radar signature with an impact field substantial enough for the objects to be recovered and made known to scientists. Many impact events occur without being observed by anyone on the ground. Between 1975 and 1992, American missile early warning satellites picked up 136 major explosions in the upper atmosphere. There is an inverse relationship between the size of the object and the frequency of such events—the bigger they are, the less frequently they hit. The following tables provide valuable information on size, frequency, and other relevant factors:
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STONY ASTEROID IMPACTS THAT GENERATE AN AIRBURST Impactor Diameter (Feet)
Energy at Atmospheric Entry (Kilotons)
Energy at Airburst (Kilotons)
Airburst Altitude (Miles)
Average Frequency (Years)
13 23 33 49 66 98 160 230 279
3 16 47 159 376 1,300 5,900 16,000 29,000
0.75 5 19 82 230 930 5,200 15,200 28,000
27.9 22.5 19/8 16.4 13.9 10.2 5.4 2.2 0.35
1.3 4.6 10 27 60 185 764 1,900 3,300
STONY ASTEROID IMPACTS THAT CREATE A CRATER Impactor Diameter (Feet)
Energy at Atmospheric Entry (Megatons)
Energy at Impact (Megatons)
Crater Diameter (Miles)
Frequency (Years)
330 430 490 660 820 980 1,300 2,300 3.300
47 103 159 376 734 1270 3010 16,100 47,000
3.4 31.4 71.5 261 598 1110 2,800 5,700 6,300
0.75 1.2 1.5 1.9 2.4 2.9 3.7 6.2 8.5
5,200 11,000 16,000 36,000 59,000 73,000 100,000 150,000 440,000
And then there are the really big ones, the devastators. Very large collisions, those with objects at least 3 miles in diameter, happen approximately once every 20 million years. The last known impact of an object of 6 miles or more in diameter was at the Cretaceous–Paleogene 36
extinction event 66 million years ago. The bottom line is that it’s 100% certain that the Earth will again be hit by a devastating asteroid; we’re just not 100% sure when that will be. Discussions about “death from above” scenarios usually center on asteroids, but a comet impact could be far more devastating than an asteroid strike. NearEarth asteroids (NEAs) have Earth-like orbits, so their collisions with Earth tend to be glancing blows from behind or from the side. Comets, on the other hand, travel around the sun in more random paths and can thus slam into the planet head-on, with potentially catastrophic results. In fact, comets can be traveling up to three times faster than NEAs relative to Earth at the time of impact. Given that the energy released by a cosmic collision increases as the square of the incoming object’s speed, a comet could pack nine times more destructive power than an asteroid of the same mass. Nevertheless, the focus on asteroids as Earth’s primary impact threat is not misplaced. The reason is simply one of numbers—the likelihood of an impact from an asteroid is probably 100 times greater than the likelihood of an impact from a comet of the same size. We have no firsthand knowledge of what the effects of an impact by a large meteorite (> 0.5 miles in diameter) or comet would be. Calculations and scaled experiments, however, have been conducted to estimate the effects, and the general consensus of scientists is as follows: • There would be a massive earthquake—up to Richter Magnitude 13—and numerous large magnitude aftershocks. •
Large quantities of dust ejected into the atmosphere would block incoming solar radiation, and could take months to settle back to the Earth’s surface. 37
•
Meanwhile, the Earth would be in a state of continual darkness, and worldwide temperatures would drop precipitously. These factors would undermine the photosynthetic processes of plants, and because photosynthetic organisms are the base of the food chain, this would seriously disrupt all ecosystems.
•
Enormous wildfires would be ignited by the radiation from the fireball, and the smoke from these fires would further block solar radiation, adding to the cooling effect and disruption of photosynthesis.
•
If the impact were to occur in the oceans, in addition to enormous tsunamis (0.5–2.0 miles high), a large steam cloud would be produced by the sudden evaporation of the seawater. This water vapor and CO2 would remain in the atmosphere long after the dust settles. Both of these gases are greenhouse gases, which scatter solar radiation and create a warming effect. Thus, after the initial global cooling, the atmosphere would undergo global warming for many years after the impact.
•
Large amounts of nitrogen oxides would result from the combining of nitrogen and oxygen in the atmosphere as a result of the shock produced by the impact. These nitrogen oxides would combine with water in the atmosphere to produce nitric acid, which would fall back to the Earth’s surface as acid rain, resulting in the acidification of surface waters.
In a best-case scenario, we might have 2 years’ or so warning of a pending collision. While 2 years might sound like a lot, more like 10 years would probably be needed 38
to prepare a space mission to intercept an object, deflect its path, and keep Earth out of harm’s way, if that’s even possible. One of the most promising deflection strategies envisions launching a robotic probe to rendezvous with and fly alongside of the incoming object, nudging it off course via a slight but persistent gravitational tug. This “gravity tractor” method obviously cannot work overnight. Another possibility, as depicted in numerous disaster films, is to use nuclear weapons to deflect or destroy the object. Currently, however, there are no detailed plans in place. In the late 20th and early 21st century, scientists put in place measures to detect near-Earth objects, and predict the dates and times of asteroids impacting Earth, along with the locations at which they will impact. The International Astronomical Union Minor Planet Center (MPC) is the global clearing house for information on asteroid orbits. NASA’s Sentry System continually scans the MPC catalog of known asteroids, analyzing their orbits for any possible future impacts. Currently, none are predicted. (The single highest-probability impact currently listed is asteroid 2010 RF12, approximately 20 feet in diameter, which is due to pass Earth in September 2095 with only a 5% predicted chance of impacting.) In September 2011, NASA announced that they had identified 911 of the 989 near-Earth objects larger than 0.5 miles in diameter estimated to exist. For mid-sized NEOs, with sizes between 300 feet and 0.5 miles, 5,200 have been found and are being tracked, but it is estimated that there are still over 15,000 of such bodies that have not yet been discovered. So far, only three impact events have been successfully predicted in advance. Currently, prediction is mainly based on cataloging asteroids years before they are due to impact. This works well for larger asteroids (> 0.5 miles in diameter) as they are easily 39
located from a long distance. Over 95% of them are already known, so their orbits can be measured and any future impacts predicted long before they are on their final approach to Earth. Smaller objects are usually too faint to observe very far in advance, so most can only be observed on final approach. A number of relatively recent incidents illustrate the Earth’s vulnerability to potential cosmic impacts. Among them are: • In March of 1989, a 0.25-mile-diameter asteroid, named 1989 FC, passed within 450.000 miles of the Earth. It was not discovered until after it had passed through the Earth’s orbit. Although 450,000 miles may seem like a long distance, it translates to a miss of the Earth by only a few hours at orbital velocities.
40
•
In March of 2004, a 100-foot-diameter asteroid, named 2004 FH, passed within 26,500 miles of the Earth, just beyond the orbit of weather satellites. The object was small, and likely would have only caused a local effect if it had hit the Earth’s atmosphere, but it was discovered only 4 days before it passed.
•
In December of 2004, astronomers calculated that an asteroid named 99942 Apophis, with a diameter of approximately 1,200 feet and a weight of 28 million tons, might hit Earth on April 13, 2029. Later calculations indicated that would not happen and that it will instead speed by at a distance of just 18,600 miles—a hair’s width in astronomical terms. (To put that distance in perspective, the Moon is located 238,900 miles away.) It was then suggested that the close proximity of the pass would alter the asteroid’s
orbit in such a way that it might impact the Earth in 2036. By May of 2013, additional observations and calculations had effectively eliminated that as a possibility. •
In November of 2011, a 1,300-foot-diameter asteroid named 2005 YU55 passed within the moon’s orbit. It was the first time such an object was known and photographed before it reached its nearest point to the Earth.
•
In June of 2012, an asteroid with a diameter greater than 0.5 miles, named 2012 LZ1, passed within about 3 million miles of Earth. Although it was never a threat, the fact that it was discovered only a few days before its passing was alarming.
While the above information might cause anxiety for some people, the odds against dying in a cosmic collision are so high, that such a possibility should not be of particular concern. There is a much greater likelihood of dying from various other natural disasters such as tornadoes, lightning strikes, and hurricanes. In fact, one has a greater chance of getting hit by all three of those at the same time. On the other hand, the odds of dying from an impact event are much higher than the odds of winning the Powerball lottery.
41
Odds of Dying in the US from Selected Causes in a Human Lifetime Cause Motor Vehicle Accident Murder Fire Firearms Accident Drowning Flood Airplane Crash Tornado Earthquake Lightning Asteroid/Comet Impact Shark Attack Odds of winning the Powerball
42
Odds 1 in 90 1 in 185 1 in 250 1 in 2,500 1 in 9,000 1 in 27,000 1 in 30,000 1 in 60,000 1 in 130,000 1 in 135,000 1 in 1,600,000 1 in 8,000,000 1 in 195,249,054
Section II
The Last Ice Age
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Introduction Most people don’t realize that we are currently in an ice age. An ice age is a lengthy period of time during which there are extensive ice sheets (masses of glacier ice that cover more than 19,000 square miles) in both the northern and southern hemispheres. Given the existence of the Greenland, Arctic, and Antarctic ice sheets, the present era qualifies as an ice age, specifically the Pliocene-Quaternary Ice Age, which began 2.6 million years ago. Within a long-term ice age, there are shorter periods of both colder climate, termed “glacial periods” (“glacials”—often colloquially called “ice ages”), and warmer periods called “interglacial periods” (“interglacials”). The world is currently in an interglacial period—the Holocene Epoch—which began with the ending of the last glacial period (“ice age”) about 11,700 years ago. This book is primarily about the period of transition from the colder Pleistocene Epoch to the warmer Holocene Eepoch, told primarily from a North American perspective.
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46
Chapter 7
Ice Ages in General An ice age is a period of long-term reduction in the temperature of the Earth’s surface and atmosphere, resulting in the presence or expansion of continental and polar ice sheets and alpine glaciers. As mentioned in the introduction, within a long-term ice age, there are shorter periods of both colder climate, termed glacial periods (“glacials”—often Alpine Glacier colloquially called “ice ages”), and warmer periods called interglacial periods (“interglacials”). The present era qualifies as a true ice age, specifically the Pleistocene-Quaternary Ice Age, which began 2.6 million years ago, and we are now in the inter-glacial Holocene Epoch, which began about 11,700 years ago. The concept of ice ages had its genesis in the early 1800s, when European scholars began to question what had caused the dispersal of erratic geological materials at 47
various locations around the world. During the winter of 1837, Louis Agassiz and Karl Friedrich Schimper developed the theory of a sequence of glaciations, and Schimper coined the term ice age for the periods of the glaciers. In July 1837, Agassiz publicly presented their synthesis, but the audience was very critical, with some opposing the new theory because it contradicted Glacial Erratic Boulder the established opinions on climatic history—that the Earth had been gradually cooling down since its birth as a molten globe. In order to overcome this resistance, Agassiz embarked on further geological fieldwork, and in 1840, published his book Study on Glaciers. It took several decades, however, until the ice age theory was fully accepted by scientists—in part, as a result of the work of James Croll, including the 1875 publication of his book Climate and Time, in Their Geological Relations, which provided a credible explanation for the causes of ice ages. There are three main types of evidence for ice ages: geological, chemical, and paleontological. • Geological evidence comes in a variety of forms, including rock scouring and scratching, glacial moraines, drumlins, valley cutting, and the deposition of till or tillites and glacial erratics. Successive glaciations tend to distort and erase previous geological evidence, making it difficult to interpret. Furthermore, this evidence was difficult to date precisely, and early theories assumed that the glacials were short compared to the longer interglacials. Later use of sediment 48
and ice cores analyses revealed that glacials are long, and interglacials are short. •
Chemical evidence consists mainly of variations in the ratios of isotopes in fossils present in sediments, sedimentary rocks, and ocean sediment cores. These ice cores provide climate proxies for the most recent glacial periods, and atmospheric samples included bubbles of air. Because water containing heavier isotopes has a higher heat of evaporation, its proportion decreases with colder conditions, thus permitting a temperature record to be constructed.
•
Paleontological evidence consists of changes in the geographical distribution of fossils. During glacial periods, cold-adapted organisms spread into lower latitudes, and organisms that had preferred warmer conditions become extinct or were squeezed into lower latitudes. This evidence is also difficult to interpret because it requires: (1) sequences of sediments that are easily correlated, covering long periods of time over a wide range of latitudes; (2) ancient organisms that survived for several million years without change and whose temperature preferences are easily determined; and (3) the finding of the relevant fossils.
Despite the difficulties, analysis of ice cores and ocean sediment cores has shown numerous periods of glacials and interglacials over the past few million years. These also confirm the linkage between ice ages and continental crust phenomena such as glacial moraines, drumlins, and glacial erratics. Hence, the continental crust phenomena are accepted as good evidence of earlier ice ages when they are found in layers created
49
much earlier than the time range for which ice cores and ocean sediment cores are available. There have been at least five major ice ages in the Earth’s history—the Huronian, Cryogenian, AndeanSaharan, Karoo, and the current Quaternary glaciation. Except for those ages, the Earth seems to have generally been ice-free, even at high latitudes. • The Huronion Ice Age, the earliest to be well documented, occurred around 2.4 to 2.1 billion years ago during the early Proterozoic Eon. It was caused by the elimination of atmospheric methane, a greenhouse gas, during the Great Oxygenation Event, which was the biologically induced appearance of dioxygen (O2) in the Earth’s atmosphere.
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•
The Cryogenian Ice Age, the next to be well documented, occurred from 850 to 630 million years ago, and was probably the most severe of the last billion years. It may have produced a “Snowball Earth” in which glacial ice sheets reached the Equator. It was possibly ended by the accumulation of greenhouse gases such as CO2 produced by volcanoes. It has been suggested that the end of this Ice age was responsible for the subsequent “Cambrian explosion” (in which most major animal phyla appeared in the fossil record), though this model is recent and controversial.
•
The Andean-Saharan Ice Age occurred from 460 to 420 million years ago, during the Late Ordovician and the Silurian Periods.
•
The Karoo Ice Age occurred between 360 and 260 million years ago during the Carboniferous and early Permian Periods. It appears to have
been the result of the evolution of land plants that caused a long-term increase in planetary oxygen levels and reduction of CO2 levels. •
The Quaternary Period, the current Ice Age, started about 2.6 million years ago with the spread of ice sheets in the Northern Hemisphere. Its initial glacial period, the Pleistocene Epoch, ended about 11.700 years ago and was followed by the current interglacial period, the Holocene. All that remains of the continental ice sheets are the Greenland, Arctic, and Antarctic ice sheets and smaller glaciers such as on Baffin Island. This Ice Age will be discussed in some detail in the next chapter.
Scientists do not yet fully understand the causes of ice ages—either the large-scale ice age periods or the smaller ebb and flow of glacial–interglacial periods within an ice age. The consensus is that there are several important interrelated factors, some of which might occur simultaneously, and thus bring about a global temperature change. Among these are: atmospheric composition, such as the concentrations of carbon dioxide and methane†; changes in the Earth’s orbit around the sun, †
An amusing aside: With today’s concerns about global warming, we hear a lot about “greenhouse gases”—carbon dioxide (continued on the bottom of next page) and methane. While most of the blame is directed toward carbon dioxide, methane nevertheless plays a significant role. Much more carbon dioxide than methane (35.9 billion tons vs. 500 million tons) is emitted annually into the Earth’s atmosphere, but methane is considerably more powerful in trapping heat. In 2012, a small team of scientists, noting that today’s cows, goats, sheep, and other large plant-eating ruminants, are a significant factor in methane release (50 to 100 million tons per year) by way of flatulence, undertook a study of how much methane dinosaurs had released in their day. Given that a cow discharges a daily average of 0.4 to 0.7 pounds of the gas, they estimated, based on body weight, that the sauropods of 160 million years ago would have each given off about 4.2 pounds per day. Guessing that there were roughly 10 dinosaurs per acre inhabiting
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known as Milankovitch Cycles; the motion of tectonic plates, resulting in changes in the relative location and amount of continental and oceanic crust on the Earth’s surface, which affect wind and ocean currents; variations in solar output; the orbital dynamics of the Earth–Moon system; and the impact of relatively large meteorites and volcanism, including eruptions of supervolcanoes. Glacial periods are subject to positive feedback, which makes them more severe, and negative feedback, which mitigates and (in all cases so far) eventually ends them. Ice and snow increase Earth’s albedo—i.e., its whiteness—which causes the Earth to reflect more of the sun’s energy and absorb less of it. This is exacerbated by the reduction in forests caused by the ice’s expansion. Hence, when the air temperature decreases, ice and snow fields grow, and continue to do so until the appearance of a negative feedback mechanism returns the system to an equilibrium. The reduction of land surface by glacial erosion reduces the amount of land above sea level and thus diminishes the amount of space on which ice sheets can form. After some time, this mitigates the albedo feedback, as does the lowering in sea level that accompanies the formation of ice sheets. Another factor is the increased aridity occurring with glacial maxima, which reduces the precipitation available to maintain glaciation. the 29 million square miles of vegetated land where they lived, they calculated that the dinosaurs’ collective flatulence contributed 520 million tons of methane to the Earth’s atmosphere. That is comparable to what is released today by all global methane sources, both natural and manmade! While that may have played a role in the global warming of the era, it clearly did not, as some reporters and others who wanted to hype the story suggest, cause the extinction of the dinosaurs. It can be said with a very high degree of certainty that they were eliminated by the climatic aftereffects resulting from a gigantic comet colliding with the Earth some 66 million years ago, and releasing 10 billion times as much energy as the nuclear bomb dropped on Hiroshima, Japan, in 1945.
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Glacial erosion is the predominant ice-related feature of high mountains such as the Alps, Himalayas, Andes, and Rockies. It has carved deep alpine valleys, and left sharp erosional remnants such as the Matterhorn in Europe. Valley glaciers near the ocean sculpted deep fjords in Norway, Greenland, northern Canada, Alaska, Chile, and Antarctica. Other large-scale examples of glacial erosion include the Great Lakes Matterhorn and the Finger Lakes of New York. In innumerable smaller examples, a combination of glacial erosion and deposition so altered the landscape as to derange the drainNorwegian Fjord age completely.
Eskers
Sediments and other geologic debris called till are deposited by glaciers, especially near their bases, sides, or fronts. Ridges of till and outwash sand left at the terminal or lateral margins of glaciers are known as moraines, and major moraine belts mark former continental ice sheets in the middle portions of North America, Europe, and Scandinavia. Till also forms drumlins, streamlined hills that 53
align with former ice movement. Moving water plays a large part in sediment deposition and subglacial erosion as well. One of the most striking landforms in formerly glaciated terrain is the esker. Eskers are sinuous ridges, generally 65 to 100 feet high, with steep side walls, and they can extend hundreds of kilometers in length. They were deposited in pressurized tunnels at the base of ice sheets during melting phases. In drier areas, extensive sand dunes and loess sheets were produced. Loess blown from outwash fans and river valleys in front of the glaciers accumulated to more than 25 feet in thickness along much of the Mississippi River Valley. Each glacial advance caused huge volumes of water that vaporated from the oceans to precipitate as snow on continental ice sheets, and to ultimately become more glacial ice. These ice sheets were as much as 5,000– 10,000 feet thick, and their enormous weight resulted in glacial land depression, with the surface of the Earth’s crust deforming and warping downward by as much as several hundred feet in some areas. At the end of each glacial period, when the glaciers retreated, the removal of the weight from the depressed land led to slow (and still ongoing) uplift or rebound of the land and the return flow of mantle material back under the deglaciated area. Due to the extreme viscosity of the mantle, typical uplift rates are on the order of only one-half inch per year or less, and it will take many thousands of years for the land to reach an equilibrium level. Given that ice sheets were formed from water evaporated from the world’s oceans, global sea levels were lowered—in some instances by as much as 650 feet. During interglacial periods, such as the present, drowned coastlines were common. While this is the case for the last 250 million years or so, with sea levels currently being near their highs for that period, in earlier 54
eras, for most of geologic time, they were even higher as a result of changes in the oceanic crust. During the Last Glacial Maximum, the final phase of the Pleistocene Epoch less than 20,000 years ago, glaciers covered ~8% of the Earth’s surface, ~25% of the Earth’s land area, and ~30% of Alaska. Glaciers today cover ~3.1% of the Earth’s surface, ~10.7% of the Earth’s land area, and ~5% of Alaska. With today’s concerns about man-made global warming, there is considerable discussion about the effects on civilization of the melting of glaciers and ice sheets. It is generally agreed that: if small glaciers and polar ice caps on the margins of Greenland and the Antarctic Peninsula were to melt, the sea level would rise about 1.5 feet; if the Greenland ice sheet were to melt, the sea level would rise about 24 feet; if the Antarctic ice sheet were to melt, the sea level would rise about 200 feet; and if all the world’s ice were to melt, the sea level would rise by about 230 feet. In the last of these scenarios, all of today’s coastal cities would be under water, and land area would shrink significantly. Not all of that ice, however, will melt. The Antarctic ice cap, where most of the ice exists, has survived much warmer times. A more realistic concern is that rising temperatures could trigger a catastrophic collapse of the West Antarctic Ice Sheet because much of it lies below sea level. The melting of West Antarctic ice would cause a rise of more than 20 feet in worldwide sea level, flooding many major cities such as Miami, New Orleans, London, Venice, and Shanghai. The models used by scientists predict that, in the absence of any such major catastrophe, the sea level is likely to rise somewhere between 1 and 3 feet in the next century, disrupting many, if not all, coastal communities.
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Chapter 8
The Most Recent Glacial Period Technically, the true “last Ice Age” (presumably meaning “latest” or “most recent”), the Quaternary Period, which began about 2.6 million years ago, is still ongoing. Its glacial period, the Pleistocene Epoch, lasted until about 11,700 years ago, when global warming brought about the current interglacial period, the Holocene Epoch. During the Last Glacial Maximum— the most recent time during the last glacial period, when ice sheets were at their greatest extension—vast ice sheets covered much of North America, northern Europe, and Asia, and profoundly affected the Earth’s climate by causing drought, desertification, and a dramatic drop in sea levels (by 400 or more feet). The Last Glacial Maximum began approximately 30,000 years ago and reached its peak about 26,500 years ago. (Note that the focus of what follows is limited almost exclusively to what occurred on the North American continent.) In North America, enormous ice sheets covered essentially all of Canada and extended roughly to the Missouri and Ohio Rivers, and eastward to New York City. (This period is often colloquially spoken of as “the last Ice 56
Age,” and it is in this sense that I will use that term from here on.) Numerous glaciers in the northern hemisphere fused together, and their movement radically altered the terrain of the land that they covered. The Cordilleran Ice Sheet covered the northwestern portion of the continent, and the eastern portion was covered by the Laurentide Ice Sheet. The Cordilleran Ice Sheet covered almost 1 million square miles of land, and at its eastern end, merged with the Laurentide Ice Sheet at the Continental Divide. The Laurentide Ice Sheet covered approximately 5 million square miles of land, including most of Canada and a large portion of the northern United States. Together, they formed an area of ice that contained 1½ times as much water as the Antarctic Ice Sheet does today. Many land areas above the 40 degrees north latitude (the current boundary between Kansas and Nebraska), were depressed as much as 600 feet by the enormous weight of the ice sheets. This, combined with rising sea levels as deglaciation began, allowed temporary marine incursions into areas that are now far from the sea, and Holocene marine fossils are today found in such places as Vermont and Michigan.
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Ice Sheet Coverage at Last Glacial Maximum
These ice sheets carved out numerous lakes, including the five Great Lakes (Lake Superior is today’s single largest freshwater lake, by area, in the world), the Finger Lakes, Lake Champlain, Lake George, and others across the northern Appalachians and throughout all of New England and Nova Scotia. The pre-glacial Teays River drainage system was radically altered and largely reshaped into the Ohio River drainage system. Other rivers were dammed and diverted to new channels, such as the Niagara River, which formed a dramatic waterfall and gorge when the water flow encountered a limestone 58
escarpment. The area from Long Island to Nantucket, Massachusetts, was, at that time, formed from glacial till. South of the ice sheets, large lakes accumulated, because water outlets were blocked and the cooler air slowed evaporation. These lakes coalesced, and when the Laurentide Ice Sheet retreated about 18,000 years ago, north central North America was totally covered by the largest of all proglacial lakes, Lake Agassiz—larger than all of today’s Great Lakes combined. Glaciers to the north blocked the natural northward drainage of the area, and the waters overflowed the Continental Divide, cutting the present Minnesota River Valley. The amount of discharge was staggering, and it contributed to the adjacent Mississippi River’s forming a very large valley. The deposition of enormous quantities of silt in Lake Agassiz caused that area to become one of the most fertile on Earth today. About 13,000 years ago, Lake Agassiz covered much of Manitoba, northwestern Ontario, northern Minnesota, eastern North Dakota, and Saskatchewan. At its greatest extent, it may have covered as much as 170,000 square miles, more than any currently existing lake in the world (including the Caspian Sea) and approximately the size of the Black Sea.
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Lake Agassiz About 13,000 Years Ago
During the Last Glacial Maximum, because of the lowering of sea levels, some continental shelves formed land bridges between landmasses that are now separate islands or continents. What is probably the most important of these connected Asia and North America about 30,000 years ago at what is now the Bering Strait. This land bridge, which has since been named Beringia, included the Chukchi Sea, the Bering Sea, the Bering Strait, and the Chukchi and Kamchatka Peninsulas in Russia as well as Alaska in the United States. Lacking heavy ice sheets, the area was not subject to glacial land depression, but it was subject to lowered sea levels, and reached a width of 620 miles wide at its greatest extent, covering an area of approximately 620,000 square miles—as large as British Columbia and Alberta put together. Because of arid conditions, snowfall in Beringia was very light, so it was not glaciated, but was, rather, a mosaic of biological communities. Steppe/tundra vegetation dominated large portions of the land, with a rich diversity of grasses and 60
herbs. There were patches of shrub tundra with isolated areas of larch, spruce, birch, and alder trees.
Beringia
The ice returned for some time, but after retreating north of the Canada–United States border around 10,000 years ago, Lake Agassiz again refilled. The last major shift in drainage occurred around 8,200 years ago. The melting of the remaining Hudson Bay ice caused Lake Agassiz to drain nearly completely. This final drainage of the lake is associated with an estimated 2.6- to 9.2-foot rise in global sea levels. Lake Agassiz’s major drainage reorganization events were of such magnitudes that they had significant impact on climate, sea level, and possibly early human civilization. 61
Major freshwater releases into the Arctic Ocean are thought to disrupt oceanic circulation and cause temporary cooling. The Lake Agassiz draining of 13,000 years ago may have been the cause of the Younger Dryas—a sharp decline in temperatures from about 12,900 to 11,650 years ago; and the draining from about 10,000 years ago may have been the cause of the 8,200-year climate event—another significant decrease in temperatures from about 8,200 to 7,800 years ago, which was milder than the Younger Dryas. This freshwater flooding of the North Atlantic may have shut down the ocean currents that conveyed warmer water from equatorial regions northward. The equatorial heat would have then warmed the waters of the various Southern Oceans, causing them to release carbon dioxide that then warmed the globe, melting back the continental ice sheets and ushering in the current warmer climate. While that theory of causation is still the most commonly accepted, there are others that include changes in the Earth’s orbit around the sun, variations in solar output, the orbital dynamics of the Earth–Moon system, the impact of relatively large meteorites, and volcanism—including eruptions of supervolcanoes. The fact is that the definitive reason for the retreat of the ice sheets remains elusive.
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Retreat of the Glaciers
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Chapter 9
Humans and Other Critters During this Late Glacial climate warming, human populations that had previously been forced into refuge areas as a result of the Last Glacial Maximum climatic conditions gradually begin to repopulate the Northern Hemisphere. The existence of the Beringia land bridge permitted the migration of land animals between Siberia and Alaska, followed later, probably no earlier than 16,500 years ago and perhaps as late as 12.600 years ago, by the migration of hunter-gatherer humans (known as PaleoIndians) from North Asia to the Americas. Late Pleistocene Hunters The most commonly accepted hypothesis is that, with the retreat of the Cordilleran and Laurentide Ice Sheets, an ice-free corridor through Alaska was formed, permitting continued human migration southward to what is now the United States and beyond. This would have occurred as the American glaciers blocking the way southward melted, but before the bridge was 64
again covered by the rising sea, approximately 11,000 years ago. The corridor would have been dominated by glacial outwash and meltwater, with ice-dammed lakes and periodic flooding from the release of ice-dammed meltwater. There is, however, scant archaeological evidence for the existence of this corridor, and, while there is general agreement that the Americas were first settled by people from Asia, the pattern of migration, its timing, and the place(s) of origin in Asia of those who migrated to the Americas remain unclear. One alternative that has been proposed is that the settlers migrated, not by inland routes, but by way of coastal routes that became ice-free when the coastal glaciers melted earlier than the mainland glaciers. Another recent hypothesis—one that would allow for the time of the settlement being even earlier—is that the earliest migrants arrived by boat, settled in ice-free coastal areas, and then moved outward from there. But there is no scientific consensus on this point, and the coastal sites that would offer further information now lie submerged in as much as 300 feet of water offshore. In 2007, geophysicist Allen West advanced a new theory to explain the transition to a warmer global environment. He suggested that approximately 12,900 years ago a comet (sometimes spoken of as the Clovis Comet) exploded just above the Earth’s surface over modern-day Canada, sparking a massive shock wave and heatgenerating event that briefly set large parts of the northern hemisphere ablaze. The wildExploding Comet fires would have briefly 65
heated up a large area, causing the Laurentide Ice Sheet to melt and send massive amounts of fresh water into the Atlantic Ocean, which would then have affected the ocean currents that are ultimately responsible for global temperatures. Additionally, the massive wildfires caused by the comet would have loaded the atmosphere with sun-blocking dust, soot, water vapor, and nitric oxides. These polluting elements would have circled the Earth for a few years, substantially reducing the amount of sunlight reaching the Earth’s surface, thereby killing off plant life and resulting in the starvation of vast numbers of herbivores and the carnivores that fed upon them. When the atmosphere cleared, temperatures rose dramatically (ushering in the Holocene Epoch) as a result of the increase in carbon dioxide released by the various Southern Oceans, as well as a decrease in the Earth’s albedo (its ability to reflect, rather than absorb, the heat of the sun) because of the reduced size of the ice sheets. The comet theory does an effective job of accounting for the abrupt plunge in temperatures during the Younger Dryas period, 12,900 to 11,650 years ago. It can also help to explain the demise of the people of the Clovis culture†, the earliest human settlers of North America, as well as the megafauna extinction of the time in which some 35 different mammal species, including the wooly mammoth, were wiped out. Findings at a paleontological site in Murray Springs, Arizona, appear to paint a clear picture of the event. There, at the appropriate depth underground, scientists unearthed the bones of a partially butchered mammoth, which were covered with what was †
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The Clovis culture is a prehistoric Paleo-Indian culture, named for distinct stone tools found near Clovis, New Mexico, in the 1920s and 1930s, and dated to approximately 12,900 years ago. Historically, the Clovis people have been considered to be the ancestors of most of the indigenous cultures of the Americas.
determined to be cometary ejecta, and directly on top of that was a thick black mat that was determined to be ash. The existence of the Clovis Comet is a highly controversial subject in the scientific community. Initially, many scientists ridiculed the idea, saying that it was the stuff of science fiction, but when they undertook field expeditions to debunk it, most of their findings ended up supporting the theory. The fact that the scientists didn’t find a distinct crater suggests that the comet exploded in the air rather than directly impacting the Earth, and that the Laurentide Ice Sheet absorbed much of the force from the explosion. North American soil samples from that era exhibited an unusually high level of iridium— an element more common in extraterrestrial objects than in the Earth’s crust. Moreover, sediments from six sites across North America yielded large quantities of nanodiamonds—found only in sediment exposed to extreme temperatures and pressures, such as those from an explosion or impact—which were conclusively sourced through X-ray diffractometry back to the diamond fields region of Canada. The only plausible scenario currently available for explaining their presence so far south is the kind of cataclysmic explosive event described by West’s theory. A similar event, but on a much smaller scale, occurred during recorded history when an extraterrestrial object exploded over Tunguska, Siberia, on June 30, 1908, flattening 800 square miles of forest. Ninety percent of the animals represented by fossils from this period can be recognized as being similar to modern forms, but there are many fossils that demonstrate spectacular differences. The Pleistocene is generally recognized as a time of gigantism in terrestrial mammals. The causes for such gigantism are not completely understood, but they most likely include a 67
response to colder conditions and an improved ability to resist predators and reach food higher on shrubs or buried beneath snow. More than three-quarters of these large Ice Age animals, both herbivores and carnivores, suffered major die-offs or extinction in a very short period of time around 12,900 years ago. This major extinction event killed off at least 35 varieties of large mammals (megafauna). Among them were carnivores such as the dire wolf, the short-faced bear, the saber-toothed cat, the American cheetah, and the American lion. Also among them were herbivores such as the wooly mammoth, the mastodon, the giant ground sloth, the woodland musk ox, and the giant beaver. These examples are each discussed below. Dire Wolf: The dire wolf was a large carnivorous mammal of the genus Canis, of the dog family Canidae. Dire wolf remains have been found across a broad range of habitats, including the plains, grasslands, and some forested mountain areas of North America. The sites range in elevation from sea level to 7,400 feet, and have rarely been located north of 42°N latitude. This range restriction is thought to be due to temperature, prey, or habitat limitations imposed by proximity to the Laurentide and Cordilleran Ice Sheets that existed at the time. The dire wolf is the largest species of the genus Canis known to have existed. Its shape and proportions were similar to those of the modern North American wolves. The largest northern wolves today, weighing between 130 and 150 Dire Wolf pounds, have a shoulder height of 38 inches and a 68
body length of 69 inches. The dire wolf’s teeth, however, were larger, with greater shearing ability than those of the modern wolf, and its bite force at the canine tooth was the strongest of any known Canis species. These characteristics are thought to have been adaptations for preying on the Late Pleistocene megaherbivores. As with other large Canis hypercarnivores today, the dire wolf is thought to have been a pack hunter. Short-faced Bear: The short-faced bear, a large carnivorous mammal, was the most common early North American bear. It was considered to be one of the largest known terrestrial mammalian carnivores that has ever existed. When walking on all fours, it stood 5–6 feet high at the shoulder, and would have been 10–11 feet tall on its hind legs. The largest of them weighed about Short-faced Bear 2,000 pounds. Despite its name, this enormous bear didn’t actually have a short face, but in comparison to its long arms and legs, it looked like it did. These long limbs likely helped it to run at higher speeds than modern bears, but scientists are still uncertain as to how and why they developed. Saber-toothed Cat: The saber-toothed cat was a large carnivorous mammal characterized by long, curved, saber-shaped canine teeth. The large maxillary canine teeth extended from the mouth even when it was closed. Sabertoothed cats were generally more robust than today’s cats and were quite bear-like in build. Saber-toothed Cat
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They were believed to be excellent hunters and preyed on large herbivorous mammals such as such as sloths, mammoths, and mastodons. The evolution of their enlarged canine teeth was presumably a result of the large size of their prey. Like modern lions, they appear to have been social carnivores. American Cheetah: The American cheetah, a large carnivore, was endemic to the prairies and plains of western North America. It stood a little taller than the modern cheetah, with an approximate shoulder height of 33 inches, a length of 67 inches, and a weight of about 150 pounds. (Some large examples weighed as much as 200 pounds.) It had a shortened face, nasal cavities that expanded for increased oxygen capacity, and legs proportioned for swift running. It was American Cheetah probably a predator of hoofed plains animals, such as the pronghorn, and may have been the reason that pronghorns evolved to run so swiftly, their 60-mph top speed being much more than was needed to outrun extant American predators, such as cougars and gray wolves. American Lion: The American lion was a large carnivore, about 25% larger than the modern African lion, making it one of the largest members of the cat family. Standing about 4 feet tall at the shoulder, it measured 5 to 8 feet long and weighed up to 900 pounds. It was smaller than its contemporary competitor, the giant short-faced bear, which was the largest carnivore of North America at the time, and was about the same size as the sabertoothed cat. It ranged from Alberta, Canada, to Maryland 70
in the US, and as far south as Mexico, inhabiting savannas and grasslands like the modern lion. It was absent from eastern Canada and the northeastern United States, perhaps because of the presence of dense boreal forests in those region. In the colder parts of its range, it probably used caves American Lion for shelter, and may have lined its den with grass or leaves, as does the Siberian tiger. The American lion most likely preyed on deer, horses, bison, mammoths, and other large hoofed mammals. Wooly Mammoth: The wooly mammoth, a large herbivore, was part of the elephant family, and its closest extant relative is the Asian elephant. It was roughly the same size as the modern African elephant, with males having a shoulder height of 9 to 11 feet and a weight up to 6 tons. It was well adapted to its cold environment during the last Ice Age, being covered in fur, with an outer covering of long guard hairs and a shorter undercoat. The ears and tail were small to minimize frostbite and heat loss. It also had a layer of fat, as much as 4 inches thick, under the skin, which helped to keep it warm. The woolly mammoth had very long tusks, which were more curved than those of modern elephants. The largest known male tusk is 14 feet long and Wooly Mammoth weighs 201 pounds, but 71
8 to 10 feet and 100 pounds was a more typical size. The tusks grew spirally in opposite directions from the base and continued in a curve until the tips pointed towards each other, sometimes crossing. It used its tusks and trunk for manipulating objects, fighting, and foraging. Its behavior was similar to that of modern elephants and, like modern elephants, woolly mammoths were likely very social and lived in matriarchal family groups. Its lifespan was probably about 60 years. The wooly mammoth’s habitat was the mammoth steppe that stretched across northern Asia, many parts of Europe, and the northern part of North America during the last Ice Age—similar to the grassy steppes of modern Russia, but the flora was more diverse, abundant, and grew faster. Grasses, sedges, shrubs, and herbaceous plants upon which the wooly mammoth fed were present, and scattered trees were mainly found in southern regions. Because of various climatic conditions at the time, this landmass was not dominated by ice and snow, contrary to what is popularly believed. Modern humans coexisted with wooly mammoths in Europe as much as 40,000 years ago, and Neanderthals did so before that. The people used the animals’ bones for building materials, tools, furniture, and musical instruments, and used their ivory for art and weapons. This was also the case in North America during the Ice Age. While several woolly mammoth specimens show evidence of being butchered by humans, it is not known how much prehistoric humans relied on woolly mammoth meat for food, because there were many other large herbivores available for that purpose. Mastodon: The mastodon, a large herbivore, was very similar in appearance to the modern elephant and, to a lesser degree, the mammoth, though not closely related to either one. Compared to the mammoth, the mastodon 72
had shorter legs, a longer body, and was more heavily built. The average American mastodon stood about 7 feet 7 inches at the shoulder, but large males could be as much as 9 feet 2 inches in height and weigh about 8.5 tons. The mastodon’s teeth were less complex than those of the mammoth, being Mastodon designed for browsing on the leaves, twigs, and branches of deciduous and coniferous trees, rather than grazing. The tusks of the mastodon were somewhat longer (up to 16 feet) than those of the mammoth and did not curve as much. Both species were covered in long, shaggy hair that protected them from the harsh conditions of their respective environments, but mammoths also had fatty humps on their backs, which provided them with the additional nutrients necessary in their more northerly, ice-covered habitats. The fossil sites for the American mastodon extend from present-day Alaska and New England in the north, to Florida, southern California, and as far south as central Mexico. Its main habitat was cold spruce woodlands, and it is believed to have browsed in herds. Based on the paleontological evidence, it can be inferred that, as with modern elephants, the mastodon social group was matriarchal and consisted of adult females and the young. The males left these groups upon reaching sexual maturity and lived either alone or in male bond groupings. Giant Ground Sloth: The giant ground sloth was a large herbivore with several genera living throughout North and South America. Megalonyx was a genus that was widespread in North America, with remains hav73
ing been found as far north as Alaska and the Yukon. Fossils have also been found in the midwestern US, southwestern US, and Mexico. Among the various giant ground sloths, it was medium-sized—9.8 feet tall and weighing about 2,200 pounds (about the size of an ox). Its South American relative, Megatherium americanum, was considerably Giant Ground Sloth larger, with a length up to 20 feet and a weight up to 10,000 pounds, making it larger than a modern African bush elephant bull. The North American giant ground sloth had a blunt snout, massive jaw, and large, peg-like teeth. Its hind limbs (which were significantly shorter than the front) were flat-footed and this, along with its stout tail, allowed it to rear up into a semi-erect position to feed on tree leaves. The forelimbs had three highly developed claws that were probably used to strip leaves and tear off branches. Its skeletal structure indicates that it was a truly massive animal, with thick bones and even thicker joints (especially those on the hind legs), which gave its appendages tremendous power that, combined with is size and fearsome claws, provided a formidable defense against predators. Giant ground sloths preferred living in forests along rivers or lakes, but they also fed in open fields. Their diet consisted primarily of tree foliage, hard grasses, shrubs, and yucca. In the US Midwest, most sloth fossils have been found in caves. In one discovery, an adult was found in direct association with two juveniles of different ages, suggesting that adults cared for young in different generations. 74
Woodland Musk Ox: The woodland musk ox, a large herbivore, was the most abundant and widespread of the musk oxen that inhabited North America during the Late Pleistocene Epoch. Musk oxen are stocky ruminant mammals with large heads, short necks, thick coats, and short, stout legs. Their name derives from the musky odor they emit during mating season, and from their superficial resemblance to the ox, but they are not closely related to cattle. The woodland musk ox was taller and less robust than the tundra muskox, with longer legs, a shorter, lighter, body, and less protruding eye orbits. Other differences were a thicker skull and considerably longer snout. Both males and females had long, curved horns. They stood 4 to 5 feet high at the shoulder, with a length of 5 to 8 feet and a weight of 650 to 900 pounds. The thick coat and large head suggested a larger animal than the muskox truly was; the bison, to which the muskox is often compared, can weigh up to twice as much. Fossils have been discovered from Alaska and Yukon to California Woodland Musk Ox and Texas, Missouri, Oklahoma, Virginia, North Carolina, and New Jersey in a wide range of habitats, including a variety of grasslands, alpine meadows, and woodlands. The woodland musk ox fed on grasses, sedges, and willows, and in the summer, stored large amounts of fat, which it used to supplement the meager forage in winter. The animals traveled in herds, often of 20–30 individuals, both male and female. While the bulls were dominant and made decisions for the groups during the 75
rutting season, the females would take charge during gestation, and decide what distance the herd traveled in a day and where they would bed for the night. Subordinate and elderly bulls would leave the herds to form bachelor groups or become solitary but, when danger was present, could return to the herd for protection. Musk oxen are not aggressive, but when attacked, the adults encircled the young and presented a formidable front of horns that was effective against Arctic wolves and dogs. When necessary, the musk ox could run at speeds up to 37 miles per hour. Their average life expectancy was on the order of 12 to 20 years. Giant Beaver: The giant beaver, a large herbivore, was generally similar in appearance to the modern beaver, but was not closely related. It was much larger, with an average length of 6.2 feet and a weight between 200 and 275 pounds, approximately the size of a black bear. (The weight of a modern beaver is roughly 44 pounds— approximately the size of a black bear. That makes it the largest known rodent in North America during the Pleistocene and the largest known beaver ever. Its hind feet were much larger than those of modern beavers, while its hind legs were shorter. Its tail was longer, but may have been narrower, and it is assumed that, like the modern beaver, it had webbed feet. One of the defining characteristics of the giant beavers was their incisors, which differed in size and shape from those Giant Beaver of modern beavers. Whereas modern beavers have chisel-like incisor teeth for gnawing on wood, the teeth of the giant beavers were bigger and broader, grew to about 6 inches long, 76
and were not as efficient at cutting wood. It is possible, therefore, that the giant beaver did not construct dams. It is thought that these animals were clumsy walkers but strong swimmers, and probably spent most of their time in the water. Their skull structure indicates that they able to engage in extended underwater activity, thanks to the ability to take more oxygen into their lungs. Another difference is that their brains were proportionately smaller, so they may have had less effective interactions with the environment as well as less complex patterns of thoughts and behavior. Fossils of the giant beaver have been found concentrated around the midwestern United States in states near the Great Lakes, particularly Illinois and Indiana, but specimens are also recorded from Alaska and Canada to Florida. The animal apparently ventured into Alaska and the Yukon during the interglacial periods but retreated south when temperatures dropped. Although most giant beavers inhabited lakes and ponds that were bordered by swamps, they were also present in spruce tundra habitats. They did not eat woody vegetation, but had a diet dominated by aquatic plants, including coarse leaves, the roots of sedges, cattails, and other such vegetation. They preferred areas with cooler annual temperatures and a long summer growing season, which would enable them to store sufficient fat to survive the winter.
Without a doubt, the Earth is currently experiencing an era of global warming. In the period from 1880 to 2012, the global average (land and ocean) surface temperature increased by 1.53 °F. In the 100-year period from 1906 to 2005, Earth’s average surface temperature rose by 77
1.33±0.32 °F. The rate of warming almost doubled in the last half of that period. Although the popular press often reports the increase of the average near-surface atmospheric temperature as the measure of global warming, most of the additional energy stored in the climate system since 1970 has accumulated in the oceans. The rest has melted ice and warmed Global Temperature Change the continents and the atmosphere. Sixteen of the 17 warmest years on record have occurred since 2000; but while record-breaking years attract considerable public attention, individual years are less significant than the overall trend. Depending on the choices that humans make with respect to energy consumption and energy production, indications are that by the end of the 21st century, the average global surface temperature will rise by another 1.0 to 6.0oF. Future climate change and associated impacts will differ from region to region. Anticipated effects include increasing global temperatures, rising sea levels, changing precipitation, and expansion of deserts in the subtropics. Warming is expected to be greater over land than over the oceans and greatest in the Arctic, with the continuing retreat of glaciers, permafrost, and sea ice. Other likely changes include: more frequent extreme weather events such as heat waves, droughts, heavy rainfall with floods, and heavy snowfall; ocean acidification; and species extinctions due to shifting temperature regimes. Effects significant to humans include the threat to food security from decreasing crop yields and the abandonment of 78
populated areas due to rising sea levels. Because the climate system has a lot of “inertia,” many of these effects will persist for not only decades or centuries, but for tens of thousands of years to come. There is considerable evidence that, over the past few hundred years, the rapid increases in human activity— especially the burning of fossil fuels—has caused the parallel rapid and accelerating increase in atmospheric greenhouse gases that trap the sun’s heat. The consensus of the scientific community is that the resulting greenhouse effect is a principal cause (with comparatively modest additional contributions from deforestation, land use changes, soil erosion, and agriculture) of the increase in global warming, which has occurred over the same period and is a chief contributor to the increasingly rapid melting of the remaining glaciers and polar ice. Since the beginning of the Industrial Revolution, there has been a 40% increase in the atmospheric concentration of carbon dioxide (CO2)—from 280 ppm in 1750 to 406 ppm in early 2017. The first 30 ppm increase took place in about 200 years, from the start of the Industrial Revolution to 1958; however, the next 90 ppm increase took place within 56 years, from 1958 to 2014. This increase, in a few hundred years, is greater than the increase that occurred at the end of the last Ice Age over a period of a few thousand years. The chart on the left shows the amount of CO2 emitted into the atmosphere by human activities since 1900. It is strikingly similar to the chart of global temperature changes (presented above) over the same period of time. Man-made CO2 Emissions This similarity, while (Billion Tons)
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not necessarily proof of cause and effect, is definitely telling. The current levels of CO2 are much higher than at any time during the last 800,000 years, the period for which reliable data has been extracted from ice cores. Less direct geological evidence indicates that CO2 values higher than this were last seen about 20 million years ago. As of 2013, the scientific consensus was that it is extremely likely that human influence has been the dominant cause of the observed warming since the mid20th century. These findings have been recognized by the national science academies of the major industrialized nations and are not disputed by any scientific body of national or international standing. Nevertheless, there are those who vehemently reject the reality of human-caused global warming. They engage in denial, dismissal, unwarranted doubt, or views contradicting the scientific opinion on climate change, including the extent to which it is caused by humans, its impacts on nature and human society, or the potential of adaptation to global warming by human actions. The disputed issues include the causes of increased global average air temperature, whether this warming trend is unprecedented or within normal climatic variations, whether humankind has contributed significantly to it, and whether the increase is completely or partially an artifact of poor measurements. Additional disputes concern estimates of climate sensitivity, predictions of additional warming, and what the consequences of global warming will be. Beginning in 1989, industry-funded organizations sought to spread doubt among the public, using a strategy previously developed by the tobacco industry. Global warming denial is most prevalent in the United States, where organizations associated with conservative economic policies and backed by industrial interests opposed to the regulation of CO2 emissions 80
have challenged the Intergovernmental Panel on Climate Change (IPCC) climate change scenarios, funded scientists who claim to disagree with the scientific consensus, and provided their own projections of the economic cost of stricter controls. The small group of scientists involved began publishing in books and the press rather than in scientific journals. As their arguments were increasingly refuted by the scientific community and new data, the deniers turned to political arguments, making personal attacks on the reputation of mainstream scientists, and promoting ideas of a global warming theory conspiracy.
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Section III
When the Earth Shudders
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Introduction Earthquakes have played a significant role in physically shaping the Earth as we know it today. They’ve been involved in structuring the land masses, building the mountain ranges, and sculpting the ocean basins. The earthquakes of millions of years ago weren’t much different from the earthquakes that occur now, but there have been so many of them over the eons that, collectively, their effects have been enormous. For example, most people know that the Himalayan Mountains were created by earthquakes, but many mistakenly believe that they resulted from a couple of “really big ones.” That is not the case. The immense present size of those mountains is attributable to the effects of hundreds or thousands of “ordinary run-of-the-mill earthquakes.” Consider that the 2005 Kashmir Earthquake added “a couple of yards” to the height of the mountain directly above its epicenter. Multiply “a couple of yards” (6 feet) by a factor of 5,000 (presumably a reasonable approximation of the number of earthquakes that might have occurred during millions of years), and the result is a mountain 30,000 feet high— the equivalent of Mount Everest. The 1960 Valdivia Earthquake that struck Chile with a magnitude of 9.5 was the most powerful earthquake in recorded history, but that’s about as big as they can get 84
under “normal” circumstances. While extremely strong earthquakes, those beyond a magnitude of 9.5, are theoretically possible, the energies involved make them effectively impossible without an extremely destructive source of external energy—such as the asteroid impact that created the Chicxulub crater near the Yucatan Peninsula in Mexico, causing the mass extinction that most likely killed off the dinosaurs. That event is estimated to have had a magnitude of 13. An earthquake with a magnitude of 15 could completely destroy the Earth. The first chapter of this book discusses the causes and nature of earthquakes. Chapters 2, 3, and 4 profile selected historical earthquakes from before 1900 (9), the 20th century (11), and the 21st century (5), respectively. The earthquakes I have selected to discuss are generally the most powerful, the most deadly, the most destructive, or the most well-known of their ilk. Appendix A provides comparative data on the selected quakes. Chapter 5 covers future earthquake risk, earthquake prediction and forecasting, and earthquake mitigation.
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Chapter 10
Earthquakes in General An earthquake is the shaking of the Earth’s surface caused by the sudden release of energy in the Earth’s lithosphere (its rigid, outermost shell), which creates seismic waves—i.e., waves of energy that travel through all the Earth’s layers). Earthquakes can range in intensity from those too weak to be felt to those violent enough to hurl people about and destroy whole cities. The seismicity or seismic activity of an area refers to the frequency, type, and size of earthquakes experienced over a period of time. At the Earth’s surface, earthquakes manifest themselves by shaking and sometimes displacing the ground. Note that the hypocenter is the focal point of the quake within the Earth’s mass, while the epicenter is the point on the Earth’s surface directly above the hypocenter. When the hypocenter of a large earthquake is located offshore, the seabed may be displaced sufficiently to cause a tsunami. Earthquakes can also trigger landslides, and, occasionally, volcanic activity. The intensity of local ground-shaking depends on several factors besides the magnitude of the earthquake and the distance from the epicenter; two of the most important are soil conditions and geographical features that may amplify or reduce the effects. 86
In its most general sense, the word “earthquake” is used to describe any seismic event that generates seismic waves. Earthquakes are caused mostly by the rupture of geological faults, but they may also occur as a result of other events such as volcanic activity, landslides, and human activity (referred ti as “induced seismicity”). Induced seismicity refers to typically minor earthquakes and tremors that are caused by human activity that alters the stresses and strains on the Earth’s crust. Causes of induced seismicity include: artificial lakes (dams); mining; waste disposal wells; hydrocarbon extraction and storage; groundwater extraction; geothermal energy; hydraulic fracturing; and carbon capture and storage. Earthquakes often occur in volcanic regions, both as a result of tectonic faults and the movement of magma in volcanoes. Such earthquakes can serve as an early warning of volcanic eruptions, as during the 1980 eruption of Mount St. Helens. An aftershock is an earthquake that occurs after a previous earthquake, which is spoken of as the mainshock. An aftershock is located in the same region as the main shock but is always of a smaller magnitude. If an aftershock is larger than the main shock, the aftershock is redesignated as the main shock and the original main shock is redesignated as a foreshock. Aftershocks are formed as the crust around the displaced fault plane adjusts to the effects of the main shock. Earthquake “swarms” are sequences of earthquakes striking in a specific area within a short period of time. They differ from earthquakes followed by a series of aftershocks because no single earthquake in the sequence has a notably greater magnitude than the others. Sometimes a series of earthquakes occur in what has been called an “earthquake storm,” wherein multiple earthquakes strike a fault in clusters, each triggered by the stress 87
redistribution of its predecessors. Similar to aftershocks but on adjacent segments of fault, these storms occur over the course of years, with some of the later earthquakes being as damaging as the early ones.
Earth’s Tectonic Plates
Most of the planet’s significant earthquakes occur because the Earth’s crust is divided into approximately 15 major segments (plates) and any number of minor ones. These plates are in constant motion relative to one another, with both earthquakes and volcanoes likely to occur around the various types of boundaries between them. The three most noteworthy plate boundaries, known as “earthquake belts,” are: • The Circum-Pacific seismic belt (often called “The Ring of Fire”), which involves several of the Earth’s tectonic plates, has a 25,000-milelong horseshoe shape, is located along the rim of the Pacific Ocean, and is where about 90% of all earthquakes, including 81% of the world’s largest, occur. It includes 452 volcanoes and is the site of over 75% of the world’s active and dormant volcanoes. All but 3 of the world’s 25 largest volcanic eruptions of the last 11,700 years 88
occurred at volcanoes in the Ring of Fire. The belt extends from Chile, northward along the South American coast through Central America, Mexico, the West Coast of the United States, the southern part of Alaska, through the Aleutian Islands to Japan, the Philippine Islands, New Guinea, the island groups of the Southwest Pacific, and to New Zealand. •
The Alpide seismic belt extends from Java to Sumatra, through the Himalayas, the Mediterranean, and out into the Atlantic. It includes: the Alps; the Carpathians; the Pyrenees; the mountains of Anatolia and Iran; the Hindu Kush; and the mountains of Southeast Asia. It is the second most seismically active region in the world, after the Circum-Pacific belt, and accounts for 17% of the world’s largest earthquakes, including some of the most destructive.
•
The Mid-Atlantic Ridge is a mid-ocean tectonic plate boundary located along the floor of the Atlantic Ocean and is part of the longest mountain range in the world. In the North Atlantic, it separates the Eurasian and North American Plates, and in the South Atlantic, it separates the African and South American Plates. Although the Mid- Atlantic Ridge is mostly an underwater feature, portions of it have enough elevation to extend above sea level, where it forms islands such as Iceland. The ridge has an average spreading rate of about 1 inch per year.
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Earth’s Principal Earthquake Belts
The three main types of tectonic plate boundaries, which are described below, play a significant role in the nature of the earthquakes that occur in their vicinities. • Divergent (or constructive) plate boundaries occur where two plates slide apart from one another, and new Earth crust is formed by the cooling and solidifying of hot molten rock. Most active divergent plate boundaries occur between oceanic plates and exist as mid-oceanic ridges at the bottom of the oceans (e.g., the “Mid-Atlantic Ridge”). Where the mid-oceanic ridge rises above sea-level, volcanic islands are formed, for example, Iceland. When a divergent boundary occurs beneath a continental plate, the pulling apart is not Divergent Plate Boundary strong enough to create a clean, 90
single break through the Earth’s surface. Instead, the continental plate is arched upwards by the lift of heat-generated convection currents, pulled thin by extensional forces, and fractured into a rift-shaped structure. As the two plates pull apart, normal faults develop on both sides of the rift, and the central blocks slide downwards. Earthquakes occur as a result of this fracturing and movement. As similar action continues over an extended period of time, a rift valley is formed, and if the rift grows deep enough, it might drop below sea level, allowing ocean waters to flow in. The East Africa Rift Valley is a classic example of a rift valley. •
Convergent (or destructive) plate boundaries occur where two plates slide toward each other and collide, forming a subduction zone in which one plate moves underneath the other and lithosphere is destroyed. At zones of oceanto-continent subduction (e.g., the “CircumPacific Seismic Belt”), the dense oceanic plate Convergent Plate Boundary plunges beneath the less dense continental plate. Earthquakes follow the path of the downward-moving plate as it descends, and as the subducted plate is heated, it releases volatiles—mostly water from hydrous minerals—into the surrounding mantle. The addition of water lowers the melting point of the mantle material above the subducting slab, causing it to melt, typically resulting in volcanism. 91
Earthquakes along convergent plate boundaries, megathrust earthquakes, are generally the most powerful of earthquakes including almost all those of magnitude 8 or more. The Earth’s major subduction zone is associated with the Pacific and Indian Oceans and is responsible for the volcanic activity that occurs along the Pacific Ring of Fire. Since these earthquakes deform the ocean floor, they often generate a significant series of tsunami waves. During collisions between two continental plates, large mountain ranges, such as the Himalayas are formed. •
Transform (or conservative) plate boundaries occur where two plates slide past each other along transform faults— neither creating nor destroying lithosphere. Strong earthquakes can occur along a Transform Plate Boundary transform fault, but volcanoes are seldom present. The San Andreas Fault in California is an example of a transform boundary.
Estimates place the number of annual worldwide earthquakes that are detectable with current instrumentation to be approximately 500,000, about 100,000 of which are large enough to be felt by humans. Minor earthquakes occur constantly, but larger earthquakes occur less frequently, with the relationship being exponential—in other words, there are roughly 10 times as many magnitude 4 earthquakes as magnitude 5 ones, and 10 times as many magnitude 5 earthquakes as 92
magnitude 6. (See below for a discussion of Earthquake Magnitude Scales.) The United States Geological Survey estimates that, since 1900, there has been an average of 18 major earthquakes (magnitude 7.0–7.9) and one great earthquake (magnitude 8.0 or greater) annually, and that this average has been relatively stable. The number of seismic stations has increased from about 350 in 1931 to many thousands today. As a result, many more earthquakes are reported than in the past, but this is because of the vast improvement in instrumentation, not because of an increase in the actual number of earthquakes occurring. The principal initial effects of an earthquake are ground shaking and rupture. These factors create the forces that cause the oscillation of buildings and other rigid structures, with resulting Earthquake-Related damage that is more or Building Damage less severe depending on a number of factors pertaining to the construction of the structures. Earthquakes can cause any number of serious secondary problems that can result in further damage or loss of life. Among these are: • Tsunamis: An offshore subduction zone earthquake can cause massive upheavals of the ocean’s floor and trigger major tsunamis that can travel great distances, causing significant damage and Earthquake-Related Tsunami
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loss of life when they come ashore, flooding everything in their path.
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•
Floods: Floods may occur as secondary effects of earthquakes if dams are damaged or if earthquakes cause landslides to dam rivers, resulting in floodEarthquake-Related Flood ing upstream while the dam stands, and downstream if it collapses.
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Landslides and avalanches: Earthquakes can produce slope instability, leading to landslides, a major geological hazard, especially in areas with water-saturated soils.
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Soil liquefaction: Soil liqueEarthquake-Related Landslide faction occurs when, because of the shaking, water-saturated granular material (such as sand) temporarily loses its bonding strength and transforms from a solid into Earthquake-Related Soil a liquid. Soil Liquefaction liquefaction can undermine the foundations and supports of struc-
tures, causing them to collapse, crumble, or sink into the ground. •
Fires: Earthquakes can cause fires by damaging electrical power or gas lines. In the event of water mains rupturing and a loss of pressure, it may also become difficult to stop the spread of a fire once it has startEarthquake-Related Fire ed.
•
Human impacts: An earthquake may cause injury and loss of life, road and bridge damage, general property damage, and collapse or destabilization (potentially leading to future collapse) of buildings. The aftermath may bring disease, lack of basic Earthquake-Related Deaths necessities, economic impact, and mental consequences in survivors, such as panic attacks and depression.
In ancient times, earthquakes were believed to be caused by restless gods or giant creatures residing beneath the surface of the Earth. In Greek mythology, Poseidon, the god of the sea, was also thought of as the god of earthquakes, and thus the cause of them. It was said that when he was angry with people and wished to inflict fear and revenge on them, he would strike the ground with his trident, causing the Earth to shake. The early Greek philosophers developed a theory that 95
earthquakes were caused by movements of gases trying to escape from underground. In 1664, Athanasius Kircher argued that earthquakes were caused by the movement of fire within a system of channels inside the Earth; in 1703, Martin Lister and Nicolas Lemery proposed that earthquakes were caused by chemical explosions within the Earth. Until the early part of the 18th century, western scientists, including Isaac Newton, thought earthquakes were caused by explosions of flammable material deep underground. After extensive study of the 1755 Lisbon Earthquake, in 1761, John Michell, an English clergyman and natural philosopher, introduced the idea that earthquakes spread out as elastic waves through the Earth and that they involve the offsets in geological strata now known as faults. He was able to estimate both the epicenter and the focus of the Lisbon earthquake, and may also have been the first to suggest that a tsunami is caused by a submarine earthquake. Study of this quake by Michell and others set in motion intensified scientific attempts to understand the behavior and causation of earthquakes. In 1857, Robert Mallet laid the foundation for instrumental seismology and carried out seismological experiments using explosives; he was also responsible for coining the word “seismology.” In 1897, Emil Wiechert’s theoretical calculations led him to conclude that the Earth’s interior consists of a mantle of silicates surrounding a core of iron. In 1906, Richard Oldham identified the differing velocities of primary (or “pressure”) and secondary (or “shear”) seismic waves, and found the first clear evidence that the Earth has a central core. In 1910, after studying the 1906 San Francisco earthquake, Harry Reid put forward the “elastic rebound theory,” which remains the foundation for modern tectonic studies. Based on his study of 96
earthquake waves, in 1926, Harold Jeffreys suggested that the core of the Earth is liquid below the mantle. In 1937, Inge Lehmann determined that within the Earth’s liquid outer core, there is a solid inner core. Today, then, the interior structure of the Earth is conceptualized as being layered in spherical shells that can be defined by their chemical and rheological (deformation and flow) properties. Earth has an outer silicate solid crust, a highly viscous mantle, a liquid outer core that is much less viscous than the mantle, and a solid inner core. By the 1960s, earth science had developed to the point where a comprehensive theory of the causation of seismic events had come together in the now well-established theory of plate tectonics. In 1935, seismologist Charles Richter developed a scale, later dubbed the “Richter Magnitude Scale,” for computing the magnitude of earthquakes. The scale is
The Earth’s Inner Structure
logarithmic, so each unit represents a 10-fold increase in the amplitude of the seismic waves and a 32-fold difference in energy. For instance, an earthquake of magnitude 6.0, as measured with a seismometer, 97
releases approximately 32 times more energy than a 5.0 magnitude earthquake, and a 7.0 magnitude earthquake releases 1,024 times (32 × 32) more energy than a 5.0 magnitude earthquake. An 8.6 magnitude earthquake releases the same amount of energy as 10,000 atomic bombs of the type dropped on Hiroshima. The energy released in an earthquake, and thus its magnitude, is proportional to the area of the fault that ruptures and the reduction in stress level in a fault when an earthquake occurs. Therefore, the longer the length and the wider the width of the faulted area, the larger the resulting magnitude. The most important parameter controlling the maximum earthquake magnitude on a fault is, however, not the maximum available length, but the available width, because the latter varies by a factor of 20. The Richter Scale is a relatively simple measurement of an event’s amplitude, and its use has become minimal in the 21st century, as most seismological authorities now express an earthquake’s strength in terms of the Moment Magnitude Scale, which is based on the actual energy released by an earthquake. All magnitude scales retain the logarithmic basis introduced by Richter and are adjusted so the mid-range approximately correlates with the original “Richter Scale.” Popular press reports of earthquake magnitude usually fail to distinguish between magnitude scales and are often reported as “Richter Magnitudes” when the reported magnitude is actually a Moment Magnitude. Because the scales are intended to report the same results within their applicable conditions, the confusion and the numerical difference is minor. In this book, for the sake of simplicity, I have chosen not to differentiate between the scales. While extremely strong earthquakes, beyond a magnitude of 9.5, are theoretically possible, the energies involved make such earthquakes on Earth effectively 98
impossible without an extremely destructive source of external energy. For example, the asteroid impact that created the Chicxulub crater—which is buried beneath the Yucatan Peninsula in Mexico and caused the mass extinction that may have killed the dinosaurs—has been estimated as causing a magnitude 13 earthquake. A magnitude 15 earthquake could destroy the Earth completely.
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Chapter 11
Selected Earthquakes Prior To 1900 Seismology is a relatively new scientific discipline. As a result, most of the information that we have about earthquakes prior to 1800 is provisional, based as it is on anecdotes and conjectural reconstruction of events. Despite the advances in scientific theory, definitive information about seismic events—even in the 19th century—is not readily available. Even today, there are those, including a number who are part of the Christian far-right, who insist that earthquakes are visited upon humans by God as punishment for their sins. I have selected for examination nine earthquakes from the period before 1900. They are profiled below:
The 365 Crete Earthquake The 365 Crete Earthquake, with an estimated magnitude of 8.6, occurred on July 21, 365, at about sunrise in the Eastern Mediterranean, with a presumed epicenter near Crete (then a part of the Roman Empire). It caused widespread destruction in central and southern Greece, north100
ern Libya, Egypt, Cyprus, Sicily, and Spain. On Crete, nearly all towns were destroyed. The quake was followed by a tsunami, with an estimate height of 100 feet, which devastated the southern and eastern coasts of the Mediterranean, particularly Libya, Alexandria, and the Nile Delta, killing thousands and hurling ships almost 2 miles inland. Recent geological studies view the 365 Crete Earthquake in connection with a clustering of major seismic activity in the Eastern Mediterranean during the era between the 4th and 6th centuries, which may have reflected a reactivation of all major plate boundaries in the region. The earthquake is believed to be responsible for a 30foot uplift of the island of Crete. An earthquake of such a size exceeds all modern ones known to have affected the region. Scientists estimate that such a large uplift is likely to occur only once in 5,000 years. The other segments of the fault, however, could slip on a similar scale—and this could happen every 800 years or so. Historians continue to debate the question of whether ancient sources refer to a single catastrophic earthquake in 365, or whether it represents a historical amalgamation of a number of earthquakes occurring between 350 and 450. The interpretation of the surviving literary evidence is complicated by the tendency of late antique writers to describe natural disasters as divine responses or warnings relative to political and religious events. The Roman historian Ammianus Marcellinus described in detail the tsunami that hit Alexandria and other locales. His account is especially noteworthy for clearly distinguishing the three main phases of a tsunami; specifically, there is an initial earthquake, followed by 365 Crete - Edifice Destruction 101
a sudden retreat of the sea, and then an ensuing gigantic wave rolling inland. He also wrote of many ships being sunk, carried inland, or perched on the roofs of houses … and of many thousands of people being killed.
The 1138 Aleppo Earthquake The 1138 Aleppo Earthquake, with an estimated magnitude of 8.5, occurred on October 11, 1138. Its name was taken from the city of Aleppo in northern Syria, where the most casualties were sustained. The main quake was preceded by a smaller quake on October 10, and several small aftershocks occurred in the weeks that followed. It was among the deadliest earthquakes in history, and is frequently listed as the third-deadliest earthquake ever, surpassed only by the 1556 Shaanxi and 1976 Tangshan earthquakes in China. The presumed death toll of 230,000, however, is based on a historical conflation of this earthquake with other Iranian earthquakes in November 1137 and September 1139. The first mention of a 230,000 death toll was in the 15th century. Aleppo is located along the northern part of the Dead Sea Transform system of geologic faults, which is a plate boundary separating the Arabian plate from the African plate. The earthquake was the beginning of the first of two intense sequences of earthquakes in the region: October 1138 to June 1139, and a later series, much more intense, from September 1156 to May 1159. The residents of Aleppo, a large city of several tens of thousands during this period, had been warned by the foreshocks and fled to the countryside before the main quake. Contemporary accounts of the damage simply state that the city was destroyed. Although Aleppo was the largest community affected by the earth102
quake, it likely did not suffer the worst of the damage. The hardest-hit area was Harim, where Crusaders had built a large citadel. The walls of the citadel collapsed, as did the walls to its east and west. A Muslim fort at Al-Atārib was destroyed as well, and several smaller 1138 Aleppo - Citadel Ruins towns and manned forts were reduced to rubble. The quake was allegedly felt as far away as Damascus, about 220 miles to the south.
The 1498 Nankai Earthquake The 1498 Nankai Earthquake, with a magnitude of 8.6, occurred off the coast of Nankaidō, Japan, on September 20, 1498, at about 8:00 AM local time. The quake caused an uplift of the seafloor by as much as 13 feet, with a much smaller subsidence near the coast, and triggered a large tsunami, estimated at 56 feet in height. Lake Hamana became a brackish lake because the tsunami broke through low-lying land between the lake and the Pacific Ocean. The southern coast of Honshu Island runs parallel to the Nankai Trough, which marks the subduction of the Philippine Sea Plate beneath the Eurasian Plate. Movement on this convergent plate boundary leads to many earthquakes, some of them of megathrust type. The Nankai megathrust has five distinct segments that can rupture independently, and the segments have ruptured repeatedly, either singly or together, over the last 1,300 years. Megathrust earthquakes on this structure tend to occur in 103
pairs, with a relatively short time gap between them. In addition to two events in 1854, there were similar earthquakes in 1944 and 1946. In each case, the northeastern segment ruptured before the southwestern segment. In the 1498 event, the earthquakes were either simultaneous, or close enough in time to not be distinguished by historical sources. Severe shaking caused by this earthquake was recorded from Bōsō Peninsula in the northeast to Kii Peninsula in the southwest. The tsunami was recorded in Suruga Bay and at Kamakura, where it destroyed the building housing the statue of the Great Buddha at Kōtoku-in. There is also evidence of severe shaking from ground liquefaction in the Nankai area. Tsunami deposits attributed to this earthquake have 1498 Nankai Destruction (1946 Recreation) been described from the coastal plains around the Sagami Trough and the Izu Peninsula. The death toll associated with this event is uncertain, but the casualties reportedly ranged between 26,000 and 31,000.
The 1556 Shaanxi Earthquake The 1556 Shaanxi Earthquake, with a magnitude of 8.0, occurred on the morning of January 23, 1556, in Shaanxi, China. The quake’s epicenter was in the Wei River Valley in Shaanxi Province. A 520-mile-wide area was destroyed, and more than 97 counties were affected, with as much as 60% of the population killed in some. 104
This catastrophic earthquake was the deadliest earthquake in recorded history, killing approximately 825,000 people. Following the earthquake, aftershocks continued several times a month for half a year. Much of the area affected was part of The Loess Plateau, named for loess, the silty soil deposited on the plateau over the ages due to wind blowing silt into the area from the Gobi Desert. Loess is highly erosion-prone soil that is susceptible to the forces of wind and water, and much of the population lived in dwellings called yaodongs, artificial caves built into the cliffs of the plateau. Many of these 1556 Shaanxi dwellings collapsed on aodongs in Loess Cliffs their occupants in landslides caused by the earthquake, and this was the major factor contributing to the horrific death toll. In the city of Huaxian, every single building and home was demolished, killing more than half the residents, with a death toll estimated in the hundreds of thousands. The situation in the cities of Weinan and Huayin was similar. In certain areas, 65-foot-deep crevices opened in the earth. Destruction and death were everywhere, affecting places as far as 300 miles from the epicenter. The earthquake also triggered landslides, which also contributed to the massive death toll. The financial cost of damage done by the earthquake is almost incalculable in modern terms—an entire region of inner China was destroyed, and an estimated 60% of the region’s population died!
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The 1693 Sicily Earthquake The 1693 Sicily Earthquake, with a magnitude of 7.4, struck parts of southern Italy near Sicily, Calabria, and Malta on January 11, 1693, at around 9:00 PM local time. The epicenter of the disaster was probably close to the coast, possibly offshore, although the exact position remains unknown. It was the most powerful earthquake in Italian history, destroying at least 70 towns and cities, seriously affecting an area of 2,200 square miles, and causing the death of about 60,000 people. According to contemporary accounts, the quaking lasted for 4 minutes. This quake was preceded on January 9 by a damaging foreshock, with an estimated magnitude of 6.2, and there were dozens of aftershocks, some as late as August 1694, and some reportedly as strong as the main quake. Aftershocks continued until at least 1696, with their effects concentrated in towns along the coast. Sicily lies on part of the complex convergent boundary where the African Plate is subducting beneath the Eurasian Plate. This subduction zone is responsible for the formation of the stratovolcano Mount Etna and considerable seismic activity. Most damaging earthquakes, however, occur on the Siculo-Calabrian rift zone, which runs for about 230 miles. A 25-foot tsunami triggered by the earthquake affected most of the Ionian Sea coast of Sicily, about 140 miles in all. The strongest effects were concentrated around Augusta, where the initial withdrawal of the sea left the harbor dry, followed by a wave of at least 8 feet in height, possibly as much as 25 feet, which inundated part of the town. The earthquake also triggered large landslides, and in one case, a large rockslide dammed a stream, forming a lake a few miles long. Several large NW-SE trend106
ing fractures, up to 1,600 feet long and 6.6 feet wide, were created on the plains just south of Catania. In the same area, sand volcanoes were formed by jets of water spurting as much as several yards into the air, with similar phenomena being reported in the Lentini plain and along some river valleys. The extent and degree of destruction caused by the earthquake led to an extensive rebuilding of 1693 Sicily - Norman Castle Ruins the towns and cities of southeastern Sicily in a homogeneous late-Baroque style.
The 1707 Hoei Earthquake The 1707 Hōei Earthquake, with an estimated magnitude of 8.6, struck south-central Japan on October 28, 1707, at 2:00 PM local time. It was the largest earthquake in Japanese history until the 2011 Tōhoku earthquake surpassed it. It caused moderate-to-severe damage throughout southwestern Honshu, Shikoku, and southeastern Kyūshū. The earthquake and the resulting destructive tsunami caused more than 5,000 casualties. This event ruptured all of the segments of the Nankai megathrust simultaneously, the only earthquake known to have done so. The uplift at Cape Muroto, Kōchi, is estimated at 7.5 feet. Along the southwestern coast of Kōchi, run-up wave heights were on the order of 33 feet. As mentioned in the profile of the 1498 Nankai Earthquake, the southern coast of Honshu runs parallel to the Nankai Trough, which marks the subduction of the 107
Philippine Sea Plate beneath the Eurasian Plate. Movement on this convergent plate boundary leads to many earthquakes, some of them of megathrust type. The quake destroyed 29,000 houses and caused more than 5,000 deaths. At least one major landslide was triggered by the earthquake, the Ohya slide in Shizuoka. This landslide, one of the three largest in Japan, involved an area of 0.7 square miles, with an estimated volume of 150 million cubic yards. The earthquake might also have triggered the last eruption of Mount Fuji. There is evidence that changes in stress caused by large earthquakes may be sufficient to trigger volcanic eruptions if the magma system involved is close to a critical state. The 1707 earthquake may have caused changes in pressure in the magma chamber beneath Mount Fuji through a static stress 1707 Hoei - Mt. Fuji Eruption (Artist’s Rendering) change; Mount Fuji erupted 49 days later on December 16, 1707.
The 1755 Lisbon Earthquake The 1755 Lisbon Earthquake, with an estimated magnitude of 8.5, occurred in the Kingdom of Portugal on Saturday, November 1, 1755, the holy day of All Saints’ Day, at around 9:40 AM local time. In combination with subsequent fires and a tsunami, the earthquake almost totally destroyed Lisbon and adjoining areas. Its epicenter is believed to have been located in the Atlantic Ocean about 120 miles west-southwest of Cape St. Vin108
cent. There were three distinct shocks over a 10-minute period. The first was followed by an even more powerful second shock that caused many buildings to collapse. A number of large fissures, up to 16 feet wide, opened up within the city. Immediately after the first shock, many townspeople fled to the waterfront, believing the area to be safe from fires and falling debris caused by aftershocks. They watched as the water receded, revealing a sea floor littered with lost cargo and shipwrecks. Some of the people sought safety on the sea by boarding ships moored on the Tagus River, but about 40 minutes after the earthquake, an enormous tsunami engulfed the harbor and downtown, racing up the Tagus River. The first tsunami wave was followed by two more waves, which hit the shore, each dragging people and debris out to sea and leaving large stretches of the river bottom exposed. Boats overcrowded with refugees capsized and sank. The height of the waves was estimated to be 20 feet. In the areas unaffected by the tsunami, fires quickly broke out, most having been started by cooking fires and candles. Many of them were rapidly extinguished, especially in the densely populated areas, but some inhabitants who fled their homes left fires burning. Narrow streets full of fallen debris prevented access to the fire sites, and within minutes, the fires spread and turned Lisbon into a raging inferno. The public squares filled with people and their rescued belongings, but as the fire approached, these squares were abandoned, and the fire reached catastrophic proportions. Two thirds of the city was destroyed by the flames that raged for 5 days. Firefighters were sent to extinguish the raging flames, and teams of workers and ordinary citizens were ordered to remove the thousands of corpses before disease could spread. Contrary to custom and against the wishes of 109
the church, many corpses were loaded onto barges and buried at sea beyond the mouth of the Tagus River. To prevent disorder in the ruined city, the Portuguese Army was deployed, and gallows were constructed at high points around the city to deter looters; more than 30 people were publicly executed. The army prevented many able-bodied citizens from fleeing, pressing them into relief and reconstruction work. Eighty-five percent of Lisbon’s buildings were destroyed, including famous palaces and libraries, as well as most examples of Portugal’s distinctive 16th-century Manueline architecture. Several buildings that had suffered little earthquake damage were destroyed by the subsequent fires. Lisbon’s magnificent museums and libraries—housing priceless documents and papers dealing with the history of Portugal’s great past—burned to the ground. Enormous numbers of works of art, tapestries, books, 1755 Lisbon - Cathedral and manuscripts were Destruction (Artist’s Rendering) destroyed. Also burned was the king’s palace and the Royal Ribera Palace, which stood just beside the Tagus River. Lisbon was not the only Portuguese city affected by the catastrophe. Throughout the south of the country, destruction was rampant. Almost all of the ports in the Azores archipelago suffered significant destruction from the tsunami, with the sea penetrating about 500 feet inland. Severe shaking was felt in North Africa, where the quake caused heavy loss of life in the towns of Algeria and Morocco more than 400 miles south of Lisbon. The town of Algiers was completely destroyed. Tangiers suf110
fered numerous deaths and extensive damage. The earthquake was particularly destructive in Morocco, where approximately 10,000 people perished. Shocks from the earthquake were also felt throughout Europe from as far away as Finland. Tsunamis as high as 66 feet swept the coast of North Africa. The tsunami took just over 4 hours to travel over 1,000 miles to the United Kingdom, where it hit Cornwall at a height of 10 feet. It also crossed the Atlantic Ocean, reaching the Lesser Antilles in the afternoon. Reports from Antigua, Martinique, and Barbados note that the sea first rose by 5 feet, followed by large waves. This event’s widespread physical effects aroused a wave of scientific interest and research into earthquakes. The Lisbon Earthquake, the first to be studied scientifically for its effects over a large area, can be said to be the wake-up call that led to the birth of modern seismology and earthquake engineering.
The 1868 Arica Earthquake The 1868 Arica Earthquake, with an estimated magnitude of 8.5–9.0, occurred on August 13, 1868, at 4:30 PM local time, near Arica, then part of Peru, but now part of Chile,. According to eyewitness reports, the shaking of the ground lasted 4 to 5 minutes, but this may have included the strong aftershocks that immediately followed the main quake. All told, about 400 aftershocks were noted in the next 2 weeks. The earthquake caused almost complete destruction in the southern part of Peru, resulting in an estimated 25,000 deaths and damages on the order of $300 million (1868 USD; $4.8 billion 2016 USD). 111
The earthquake occurred along the boundary between the Nazca Plate and the South American Plate. The earthquake was likely a result of thrust-faulting, caused by the subduction of the Nazca plate beneath the South American plate. A 370-mile rupture length has been estimated, making it one of the largest fault breaks in modern times. A tsunami (or multiple tsunamis) in the Pacific Ocean was produced by the earthquake, and was observed in Hawaii, Japan, Australia, and New Zealand. Hawaii was hit particularly hard; run-up reached 15 feet at Hilo, causing severe damage to the waterfront. Further west, the tsunami generated 5 feet of run-up in Japan, and flooded the harbor of Yokohama. The tsunami also generated sizable run-up and some damage in New Zealand, where heights reached 16 feet. Locally, tsunami waves caused extensive destruction to coastal towns and ports along the coasts of Southern Peru and Northern Chile. The first wave arrived at Arica 52 minutes after the earthquake, with a 39-foot height, followed by the largest wave, at 52 feet, 73 minutes later. The tsunamis were disastrous for the port of Arica. They literally swept the low-lying parts of the town clean, removing all traces, including the foundations, of the structures that once existed there. The first sea-level fluctuation was a withdrawal of the water 22 minutes after the quake, causing ships in the harbor to sit on the bottom. Two subsequent waves crashed on the port’s wharf—the first sweeping away the people who were providing aid to the crew of beached ships. Approximately 2 hours later, two more waves violently struck the coastal area of Arica, spreading widespread destruction. There were several ships anchored offshore near Arica at the time; two were US Navy ships—the USS Fredonia and the USS Wateree. When the water first withdrew, the Fredo112
nia sat on the bottom, and the maximum wave, 2 hours after the quake, wrecked it and most other ships in the harbor. The tsunami drove three of the ships anchored in port nearly 2,600 feet inland: the Peruvian corvette America, the US gunboat Wateree, and the US store ship Fredonia (which was completely destroyed). 1868 Arica - USS Wateree Aground When the ocean finally returned to normal, the Wateree was, amazingly, still in near-perfect condition … sitting on the beach 1,290 feet from the water! Despite the height and ferocity of the tsunami, only one casualty was reported aboard that ship. The Americana however, was not as fortunate; it lost 83 men, including the captain.
The 1896 Sanriku Earthquake The 1896 Sanriku Earthquake, with a magnitude of 8.5, occurred on June 15, 1896, at 7:32 PM local time. Its epicenter was located approximately 100 miles off the coast of Iwate Prefecture, Honshu, Japan. This earthquake was one of the most destructive seismic events in Japanese history, causing 22,066 deaths and destroying about 9,000 homes. It resulted in two tsunamis with waves reaching a height of 125 feet, which was a record until the 2011 Tohoku Earthquake. The epicenter was just to the west of the Japan Trench, which is the surface expression of the west-dipping subduction zone that forms part of the convergent boundary between the Pacific and Eurasian plates. 113
There was little awareness of the earthquake itself when it occurred because of its distance from shore and because of its character, but the tsunami that ensued was massive and caused overwhelming damage on shore. After what was experienced by people as a small earthquake, there was little concern because it was so weak and also because many other small tremors had been felt in the previous few months. However, 35 minutes later, the first tsunami wave struck the coast, followed by a second wave 5 minutes afterward. In some locations, the wave reached a height of 125 feet, destroying everything in its path. Damage was particularly severe because the tsunamis coincided with high tides. As was usual each evening, the local fishing fleets were all at sea when the tsunamis struck. In the deep water the waves went unnoticed. Only when the fishermen returned to port the next morning did they become aware of the debris and bodies. The violence of the tsu1896 Sanriku Grounded Fishing Vessel nami was extraordinary. Generally, victims in tsunami disasters die by drowning, but in the Sanriku event, there was extensive damage to the bodies of the casualties—fractured skulls, bodies heavily scarred, and legs and arms broken. The impact of this tsunami carried across the Pacific. In Hawaii, wave heights of up to 30 feet were observed, resulting in wharves being demolished and several houses being swept away. In California, a 9.5-foot-high wave was experienced. Seismologists have found that the tsunami’s magnitude was much greater than expected for the estimated 114
seismic magnitude, and this earthquake is now regarded as being part of a distinct class of seismic events, the tsunami earthquake. Such events are a result of relatively slow rupture velocities. They’re particularly dangerous, because, as in this case, a large tsunami may arrive at a coastline with little or no warning.
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Chapter 12
Selected 20th-Century Earthquakes John Mitchell’s 1761 theory, based on his study of the 1755 Lisbon Earthquake, was that the propagation of elastic waves through the structure of the Earth caused earthquakes was ahead of its time. However, by 1900, the nascent discipline of seismology was established, and earthquakes were being studied from a truly scientific perspective. In 1910, after studying the 1906 San Francisco earthquake, Harry Reid put forward the “elastic rebound theory,” which remains the foundation for modern tectonic studies. I have selected for examination 11 earthquakes from the 20th century. They are profiled below:
The 1906 San Francisco Earthquake The 1906 San Francisco Earthquake, with an estimated magnitude of 7.8, struck the coast of Northern California on April 18, 1906, at 5:12 AM local time, and the shaking lasted about 42 seconds. About 25 seconds before the main shock, there was a significant foreshock, 116
and the quake was followed by a number of aftershocks. Severe shaking was felt from Eureka on the North Coast to the Salinas Valley, an agricultural region to the south of the San Francisco Bay Area. Devastating fires soon broke out in the city and lasted for several days. As a result, approximately 3,000 people died and more than 80% of the city of San Francisco was destroyed. Property losses from the disaster were estimated at more than $400 million (1906 USD; $10.1 billion 2016 USD). This is remembered as one of the worst and deadliest earthquakes in the history of the United States. The death toll remains the greatest loss of life from a natural disaster in California’s history and high on the list of American urban disasters. The San Andreas Fault is a continental transform fault that forms part of the tectonic boundary between the Pacific Plate and the North American Plate. The 1906 rupture propagated both southward and northward for a total of 296 miles. This fault runs the length of California from the Salton Sea in the south to Cape Mendocino in the north, a distance of about 810 miles. The maximum observed surface displacement from the quake was about 20 feet. As damaging as the earthquake and its aftershocks were, the fires that burned out of control afterward were even more destructive. It has been estimated that up to 90% of the total destruction was the result of the subsequent fires. Within 3 days, over 30 fires caused by ruptured gas mains destroyed approximately 25,000 buildings on 490 city blocks. Some were started when 1906 San Francisco City in Flames
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firefighters untrained in the use of dynamite attempted to demolish buildings to create firebreaks. The dynamited buildings themselves often caught fire. Out of a total city population of approximately 410,000, about 250,000 people were left homeless; half of those who evacuated fled across the bay to Oakland and Berkeley. Newspapers described Golden Gate Park, the Presidio, the Panhandle, and the beaches between Ingleside and North Beach as covered with makeshift tents. More than 2 years later, many of these refugee camps were still in operation. Although the impact of the earthquake on San Francisco was the most famous, considerable damage was also inflicted on several other cities. These include San Jose and Santa Rosa, the entire downtown of which was essentially destroyed. Most of the deaths occurred in San Francisco itself, but 189 were reported elsewhere in the Bay Area. In Monterey County, the earthquake permanently shifted the course of the Salinas River near its mouth, diverting it 6 miles south to a new channel.
The 1908 Messina Earthquake The 1908 Messina Earthquake, with a magnitude of 7.5, occurred on December 28, 1908, at about 5:20 AM local time. Its epicenter was in the Strait of Messina which separates the busy port city of Messina in Sicily and Reggio Calabria on the Italian mainland. The quake had a depth of 5–6 miles, the ground shook for 30–40 seconds, and the damage was widespread, with destruction experienced within a 190-mile radius. The cities of Messina and Reggio Calabria were almost completely destroyed, and a total of approximately 120,000 lives 118
were lost. This was the most destructive earthquake ever to strike Europe. Italy sits along the boundary zone of the African Continental Plate, and this plate is pushing against the seafloor underneath Europe at a rate of approximately 1 inch per year. This causes vertical displacement, which in turn can cause earthquakes. The earthquake nearly leveled Messina; at least 91% of the structures in the city were destroyed or irreparably damaged, and almost half the population lost their lives. Reggio Calabria and other locations in Calabria also suffered heavy damage, with Reggio’s historic center being almost completely eradicated. The elevated death toll was due to the fact that most people were asleep, and were therefore killed outright or buried alive in their beds as their houses collapsed on top of them. Thousands were trapped under debris, suffering horrific injuries from which many died. About 10 minutes after the earthquake, the sea on both sides of the Strait suddenly withdrew 230 feet from the shore as a 39-foot tsunami formed. Three waves then struck nearby coasts, impacting hardest along the Calabrian coast and inundating Reggio Calabria. The entire Reggio seafront was destroyed, and a great number of people who had gathered there perished. In Messina, the tsunami also caused more devastation and deaths; many of the survivors of the earthquake had fled to the supposed relative safety of the seafront to escape their collapsing houses. The second and third tsunami waves, coming in rapid succession and higher than the first, 1908 Messina -Tsunami Strike raced over the harbor, 119
smashed boats docked at the pier, and broke parts of the sea wall. After engulfing the port and rushing 100 yards inland beyond the harbor, the waves swept away people, a number of ships that had been anchored in the harbor, fishing boats, and ferries; and it inflicted further damage on the edifices within the zone that had remained standing after the shock. The Messina shoreline was irrevocably altered as large sections of the coast sank several feet into the sea. Huge crevasses and fissures opened in the streets, and these—as well as the mounds of rubble and falling masonry—hampered those survivors who had fled from their razed homes to seek safety. Families had become separated, and a torrential downpour of rain that had begun only minutes before the earthquake added to the confusion and impeded visibility that was worsened further by the darkness and thick clouds of dust. Outbreaks of fire caused by broken gas pipes also added to the chaos and destruction. The ground continued to shake with repeated aftershocks, causing remaining structures to topple down onto the ruins of demolished edifices, killing and injuring rescuers and those who had survived the main shock. Hospitals in both Messina and Reggio Calabria lay in ruins, with nearly all the doctors and nurses dead. The injured in the two cities had no medical support or medicine until outside relief arrived. Telegraph lines were severed and railway lines were mangled, making communication impossible. Most of Messina’s officials were killed or gravely injured, as were nearly all members of the police force and the soldiers of its garrison, who perished when their respective barracks collapsed. Prisoners who had escaped death when the prison was destroyed began looting property and even robbing corpses of their jewelry. Peasants from nearby 120
rural villages joined the looters. Troops were soon sent to the city and martial law was declared.
The 1920 Haiyuan Earthquake The 1920 Haiyuan Earthquake, with a magnitude of 7.8, occurred on December 16, 1920, at 8:06 PM local time, in Haiyuan County, Ningxia Province, Republic of China. The earthquake affected an area of some 25,000 square miles, including 10 major population centers, and caused total destruction in the Lijunbu-Haiyuan-Ganyanchi area. About 125 miles of surface faulting was 1920 Haiyuan seen, and there were nuDestroyed Buildings merous landslides and ground cracks throughout the epicentral area. Some rivers were dammed; others changed course. The death toll was 273,419, and the estimated property damage was approximately $20 million (1920 USD; $1.3 billion 2016 USD). The quake was followed by a series of aftershocks for 3 years. This was one of the world’s two deadliest earthquakes in the 20th century; the other was the 1976 Tangshan Earthquake. The great devastation caused by the earthquake was due largely to poor soil conditions throughout the Gansu province, and by the fact that for almost 300 years, there had been no recorded earthquakes in the region to stabilize gradual changes to the landscape. Situated along a stretch of the Yellow River south of the Gobi Desert, the area around Haiyuan is part of the most extensive stretch of loess terrain on Earth. Cave dwellings dug out of loess 121
were the predominant form of home construction in the area and were particularly susceptible to collapse under seismic activity. The destruction of homes and granaries beneath collapsed hills subjected the initial survivors both to hunger and to exposure to the windstorms and snowfall that immediately followed the quake. Vulnerable to bandit activity, many thousands roamed in a deformed landscape, which was stripped of its roads and devoid of standing structures and familiar natural landmarks. It is unclear what portion of total fatalities was due to starvation or exposure in the quake’s aftermath, but investigators estimated landslides claimed at least 100,000 human lives outright.
The 1923 Kanto Earthquake The 1923 Kantō Earthquake, with a magnitude of 7.9, occurred on September 1, 1923, at 11:58 AM local time. It struck the Kantō Plain on the Japanese main island of Honshū. Its focus was 14 miles beneath Izu Ōshima Island in Sagami Bay; its duration was somewhere between 4 and 10 minutes; and there were 57 aftershocks. This earthquake devastated Tokyo, the port city of Yokohama, and the surrounding prefectures of Chiba, Kanagawa, and Shizuoka. It also caused widespread damage throughout the Kantō region. The quake caused an estimated 142,800 deaths, including those who were missing and presumed dead. Over 570,000 homes were destroyed, leaving an estimated 1.9 million people homeless. The damage is estimated to have exceeded $1 billion (1923 USD; $14 billion 2016 USD). The cause of this earthquake was a rupture of part of the convergent boundary where the Philippine Sea Plate 122
is subducting beneath the Okhotsk Plate along the line of the Sagami Trough. Because the earthquake struck at lunchtime, when many people were cooking meals over fires, a large number of people died as a result of multiple large fires that broke out. Some fires developed into firestorms that swept across cities. Many people died when their feet became stuck on melting tarmac. The single greatest loss of life was caused by a fire tornado that engulfed one location in downtown Tokyo, where about 38,000 people were incinerated after taking shelter there following the earthquake. The earthquake broke water mains all over the city, and it 1923 Kanto - Firestorm took nearly two full days to extinguish the fires. A strong typhoon centered off the coast brought high winds to Tokyo Bay at about the same time as the earthquake, causing fires to spread rapidly. Many homes were buried or swept away by landslides in the mountainous and hilly coastal areas in western Kanagawa Prefecture, and a collapsing mountainside in the village of Nebukawa, which is west of Odawara, pushed the entire village and a passenger train carrying over 100 passengers into the sea. Additionally, a tsunami with waves up to 33 feet high struck the coast of Sagami Bay, Bōsō Peninsula, Izu Islands, and the east coast of Izu Peninsula within minutes, causing numerous deaths. In the confusion after the quake, false rumors led mobs in urban Tokyo and Yokohama—who believed Koreans with bombs were taking advantage of the disaster by committing arson and robbery—to carry out 123
mass murder of Koreans. Anti-Korean sentiment was heightened by fear of the Korean independence movement, partisans of which were responsible for assassinations of top Japanese officials and other activities. The government reported 231 Koreans were killed by mobs in Tokyo and Yokohama in the first week of September. Independent reports said the number of dead Koreans was far higher, ranging from 6,000 to 10,000.
The 1960 Valdivia Earthquake The 1960 Valdivia Earthquake—with a magnitude of 9.5 and shaking that lasted approximately 10 minutes— struck the coast of Chile on May 22, 1960, at 3:11 PM local time. It affected all of Chile between Talca and Chiloé Island, more than 150,000 square miles. The epicenter of this megathrust earthquake was located approximately 350 miles south of Santiago, with Valdivia being the most affected city. Its measured magnitude of 9.5 makes it the most powerful earthquake ever recorded. The Valdivia quake was the largest in a sequence of strong earthquakes that affected Chile between May 21 and June 6. They were caused by the release of mechanical stress between the subducting Nazca Plate and the South American Plate on the Peru–Chile Trench. Earthquake-induced tsunamis affected southern Chile, Hawaii, Japan, the Philippines, China, eastern New Zealand, southeast Australia, and the Aleutian Islands. Some localized tsunamis severely battered the Chilean coast, with waves up to 82 feet high. Across southern Chile, the tsunami caused enormous loss of life, damage to port infrastructure, and the destruction of many small boats. The main tsunami crossed the Pacific Ocean at a speed of several hundred miles per hour and devastated 124
Hilo, Hawaii, killing 61 people. Waves as high as 35 feet were recorded 6,200 miles from the epicenter and as far away as Japan and the Philippines. The earthquake also triggered numerous landslides, mainly in the steep glacial valleys of the southern Andes. A number of Spanish colonial-era fortifications were completely demolished. Witnesses reported underground water flowing up through the soil, and the resulting soil liquefaction and subsidence destroyed buildings, deepened local rivers, and created wetlands in places where they hadn’t existed previously. Extensive areas of the city were flooded, and the electricity and 1960 Valdivia Damage water systems of Valdivia were completely destroyed. Despite the heavy rains of May 21, the city was left without a potable water supply, and this became a serious problem in one of Chile’s rainiest regions. Two days after the earthquake, Cordón Caulle, a volcanic vent close to the Puyehue volcano, erupted. Other volcanoes may also have erupted, but none was reported due to the lack of communication in Chile at the time. The death toll and monetary losses arising from this widespread disaster are not certain. Published estimates of fatalities from the earthquake and tsunami, combined, averaged about 3,500. Given the strength of the earthquake, this relatively low number is explained in part by the low population density in the region. The average of the published estimated damages is about $600 million (1960 USD; $4.8 billion 2016 USD). 125
The 1964 Alaska Earthquake The magnitude-9.2 1964 Alaska Earthquake occurred on Good Friday, March 27, 1964, at 5:36 PM local time, and lasted 4 minutes and 38 seconds. The epicenter of this megathrust earthquake was 12.4 miles north of Prince William Sound, 75 miles east of Anchorage and 40 miles west of Valdez. The focus occurred at a depth of approximately 15.5 miles. There were hundreds of aftershocks following the main shock. In the first day alone, 11 major aftershocks with a magnitude greater than 6.0 were recorded. Nine more struck over the next 3 weeks. In all, thousands of aftershocks occurred in the months following the quake, and smaller aftershocks continued to strike the region for more than a year. This was the most powerful earthquake recorded in North American history, and the second most powerful (after the 1960 Valdivia Earthquake) in world history. The event was a subduction-zone earthquake along the Aleutian Megathrust Fault between the Pacific and North American plates in Prince William Sound. Ocean floor shifts created large tsunamis, which caused many of the deaths and much of the property damage. Large rockslides, which caused considerable property damage, also occurred. Vertical displacement of up to 38 feet occurred, affecting an area of 100,000 square miles within the state. Two types of tsunamis were produced by this earthquake—a large tectonic tsunami and about 20 smaller local tsunamis. These smaller tsunamis were produced by submarine and subaerial landslides and were responsible for the majority of the tsunami damage. Tsunami waves were noted in over 20 countries, including: Peru, New Zealand, Papua New Guinea, Japan, the Gulf of Mexico, 126
and Antarctica. The largest tsunami wave was recorded in Shoup Bay, Alaska, with a height of about 220 feet. Most coastal towns in the Prince William Sound, Kenai Peninsula, and Kodiak Island areas—especially the major ports of Seward, Whittier, and Kodiak—were heavily damaged by a combination of seismic activity, subsidence, post-quake tsunamis, and/or earthquakecaused fires. Port Valdez suffered a massive underwater landslide, resulting in the deaths of 30 people. Nearby, a 27-foot tsunami destroyed the village of Chenega, killing 23 of the 68 people who lived there; survivors outran the wave, climbing to high ground. Valdez was not totally destroyed, but after 3 years, the town relocated to higher ground 4 miles west of its original site. Soil liquefaction, fissures, landslides, and other ground failures caused major structural damage in several communities and much damage to property. Anchorage, 75 miles northwest of the epicenter suffered the most damage. The city was not hit by tsunamis, but its downtown was heavily damaged, and parts of the city built on sandy bluffs suffered landslide damage. Buildings and infrastructure—particularly in the landslide zones—were heavily damaged or destroyed. Two hundred miles southwest, some 1964 Alaska Destruction areas near Kodiak were permanently raised by 30 feet. Southeast of Anchorage, some areas dropped as much as 8 feet, requiring reconstruction and fill to raise the Seward Highway above the new high-tide mark. Alaska had never before experienced a major disaster in a highly populated area and had very limited resources for dealing with the effects of such an event. The mili127
tary, which has a large active presence in Alaska, stepped in to assist within moments of the end of the quake. The Army rapidly re-established communications with the lower 48 states, deployed troops to assist the citizens of Anchorage, and dispatched a convoy to Valdez. On the advice of military and civilian leaders, President Lyndon Johnson declared all of Alaska a major disaster area the day after the quake. The number of people who perished as a result of the earthquake is believed to have been 139; 15 died as a result of the earthquake itself, 106 died from the subsequent tsunami in Alaska, 5 died from the tsunami in Oregon, and 13 died from the tsunami in California. Property damage was estimated at about $311 million (1964 USD; $2.4 billion 2016 USD).
The 1970 Ancash Earthquake The 1970 Ancash Earthquake, with a magnitude of 7.9, occurred on May 31, 1970, at 3:23 PM local time, and lasted about 45 seconds. The epicenter was located off the coast of Casma and Chimbote, Peru, in the Pacific Ocean, where the Nazca Plate is being subducted by the South American Plate. Despite its being an undersea quake, the tsunami it triggered was minimal. The earthquake affected an area of about 32,000 square miles in the north central coast and the highlands of the Ancash and southern La Libertad Regions. As a result of the landslides the quake triggered, it was the worst catastrophic natural disaster in the history of Peru. It is also considered to be the world’s deadliest avalanche. The northern wall of the 22,205-foot Mount Huascarán was destabilized, causing an avalanche that buried the towns of Yungay and Ranrahirca. The avalanche 128
started as a sliding mass of glacial ice and rock that was about 3,000 feet wide and 1 mile long. It advanced about 11 miles to the village of Yungay at an average speed of about 200 miles per hour. The fast-moving mass picked up glacial deposits and by the time it reached Yungay, it is estimated to have consisted of about 100 million cubic yards of water, mud, rocks, and 1970 Ancash - Yungay Statue snow. The Peruvian government has since forbidden excavation in the area in the town of Yungay where some 20,000 of its inhabitants are buried, declaring it a national cemetery. The earthquake impacted such a widespread area that the regional infrastructure of communications, commerce, and transportation was destroyed. Cities, towns, and villages—as well as the homes, industries, public buildings, schools, and electrical, water, sanitary, and communications facilities therein—were seriously damaged or destroyed. In some communities, about 80% to 90% of buildings were destroyed, and, overall, some 3 million people were affected. The Pan-American highway was also damaged, which made the arrival of humanitarian aid difficult. The Cañón del Pato hydroelectricity generator was damaged by the Santa River, and 60% of the railway route connecting Chimbote with the Santa Valley was left unusable. The total number of fatalities resulting from the earthquake was about 70,000. Economic losses were estimated to have surpassed $500 million (1970 USD; $3.1 billion 2016 USD). 129
The 1976 Tangshan Earthquake The 1976 Tangshan Earthquake, with a magnitude of 8.0, occurred on July 28, 1976, at about 4:00 AM local time, and lasted approximately 15 seconds. Its epicenter was near Tangshan, People’s Republic of China, an industrial city with approximately one million inhabitants. The quake was caused by the rupture of the 25-mile-long Tangshan Fault, which runs near the city, when tectonic forces exerted from the Amurian Plate were sliding past the Eurasian Plate. Tremors were experience as far as 470 miles away. The main quake was followed by a 7.1-magnitude aftershock some 16 hours later. The Tangshan quake is believed to be the deadliest earthquake of the 20th century. The earthquake devastated the city over an area of approximately 20 square miles, and 85% of its buildings collapsed in ruins or were rendered uninhabitable. Many of the people who survived the initial shock were trapped under collapsed buildings. The resultant high loss of life can be attributed to the time the quake struck, the suddenness with which it struck (there were no foreshocks), and the quality and nature of building construction. Tangshan itself was thought to be in a region with a relatively low risk of seismic events, so very few 1970 Ancash - Yungay Statue buildings had been built to withstand an earthquake, and the city also lies on unstable alluvial soil. 130
Insisting on self-reliance, the Chinese government refused to accept international aid from the United Nations. Shanghai sent 56 medical teams to Tangshan, in addition to the People’s Liberation Army, who were assisting while also trying to fix their tarnished image as Red Guard suppressors. Rebuilding infrastructure started immediately in Tangshan, and the city was completely rebuilt. Today Tangshan city is home to nearly three million people and is known as “the Phoenix City.” The death toll figure of 242,419 came from the Chinese Seismological Service in 1988, but several other sources say that number is significantly understated, and some place it as high as 650,000. The economic losses totaled an estimated $1.5 billion (1976 USD; $6.3 billion 2016 USD).
The 1985 Mexico City Earthquake The 1985 Mexico City Earthquake, with a magnitude of 8.0, struck on September 19, 1985, at 7:17 AM local time. The quake was a multiple event, with two epicenters; with the second shock occurring 26 seconds after the first. Because of multiple breaks in the fault line, the event was of long duration; ground shaking lasted more than 5 minutes in places along the coast and for 3 minutes in parts of Mexico City. The sequence of events included a foreshock that occurred the prior May, the main shock on September 19, and two large aftershocks. The epicenter was located in the Pacific Ocean, off the coast of the Mexican state of Michoacán, in the Cocos Plate subduction zone, a distance of more than 220 miles from the city. The Cocos Plate pushes against and subducts under the North American Plate. It is estimated the movement along the fault was about 3 yards. There 131
were also at least 12 other minor aftershocks associated with the seismic event. While this was an undersea quake, there was relatively little impact on the sea itself. The earthquake did produce a number of tsunamis, but they were small, ranging between 3 feet and 10 feet in height. While not on or near a fault line, like San Francisco or Los Angeles, Mexico City is highly vulnerable to earthquakes, primarily due to the surface geology of the area—especially in the downtown area. Over time, the city had grown outward from an island in the middle of Lake Texcoco; on the bed of the lake, the prevailing silt and volcanic clay sediments amplify seismic shaking. Damage to structures is worsened by soil liquefaction, which causes the loss of foundation support and contributes to dramatic subsidence of large buildings. Another factor is that the lakebed resonates with certain seismic waves and low-frequency signals, thus amplifying the effects of the shock waves coming from an earthquake far away. Only certain types of structures, however, are vulnerable to this resonance effect. Taller buildings have their own frequencies of vibration, but those that are 6–15 stories tall vibrate in resonance with the seismic waves of an earthquake, making them act like tuning forks. The low-frequency waves of an earthquake are amplified by the mud of the lakebed, which in turn, is amplified by the building itself. This causes these buildings to shake more violently than the earthquake proper. Many of the older colonial buildings have survived hundreds of years on the lakebed simply because they are not tall enough to be affected by the resonance effect. About 5,000 bodies were recovered from the debris and represent the total of legally certified deaths, but this does not include those who went missing and were never recovered. Researchers have numbered the dead 132
anywhere from 5,000 to 30,000, the most commonly cited figures being around 10,000. While high as an absolute number, it is considerably lower than other earthquakes of similar strength in Asia and other parts of Latin America, where death tolls have run between 1985 Mexico City Destruction 66,000 and 242,000. This is partly explained by the hour at which the earthquake struck (7:17 AM), when people were awake but not in the many schools and office buildings that were severely damaged. The event caused approximately $3.5 billion (1985 USD; $7.8 billion 2016 USD) in damages.
The 1989 Loma Prieta Earthquake The 1989 Loma Prieta Earthquake, with a magnitude of 6.9, occurred in Northern California on October 17, 1989, at 5:04 PM local time. The shock was centered approximately 10 miles northeast of Santa Cruz on a section of the San Andreas Fault system and was named for the nearby Loma Prieta Peak in the Santa Cruz Mountains. That segment of the San Andreas Fault system had been relatively inactive since the 1906 San Francisco earthquake until two moderate foreshocks occurred, one of magnitude 5.3 in June of 1988, and the other of magnitude 5.4 in August of 1989. Historically, earthquake research in California has been largely focused on the San Andreas Fault system because of its strong influence in the state as the boundary between the Pacific Plate and the North American Plate. Given that there had been numerous earthquake 133
forecasts for the Loma Prieta region, and two moderate foreshocks, the October 1989 event did not take seismologists by surprise. While the effects of a 4-year drought limited the potential for landslides, the steep terrain near the epicenter was prone to movement, and up to 4,000 landslides may have occurred during the quake, the majority of them to the southwest of the epicenter, but also along the bluffs of the Pacific Coast and as far north as the Marin Peninsula. Other areas with certain soil conditions were susceptible to site vibrational amplification due to the effects of soil liquefaction, especially near the shore of San Francisco Bay and, to the west of the epicenter, near rivers and other bodies of water. Damage was heavy in Santa Cruz County, and less so to the south in Monterey County, but effects extended well to the north into the San Francisco Bay Area, both on the San Francisco Peninsula and across the bay in Oakland. There was no surface faulting, but a large number of other ground failures and landslides occurred. Due to the sports coverage of the 1989 World Series that was then in progress in San Francisco, Loma Prieta became the first major earthquake in the United States to be broadcast live on national television. Rush-hour traffic on the Bay Area freeways was lighter than normal because the game was about to begin, and this may have prevented a greater loss of life, as several of the Bay Area’s major transportation structures suffered catastrophic failures. The most disastrous 1989 Loma Prieta event of the earthquake Cypress Street Viaduct 134
was the collapse of the two-level Cypress Street Viaduct of Interstate 880 in West Oakland. The failure of a 1.25mile section of the viaduct killed 42 and injured many more. During the earthquake, the freeway buckled and twisted to its limits before the support columns failed and sent the upper deck crashing down onto the lower deck. The San Francisco–Oakland Bay Bridge also suffered severe damage, as a 76-by-50-foot section of the upper deck on the eastern cantilever side fell onto the deck below, resulting in one fatality. Collapsing structures caused the deaths of six people in Santa Cruz and five in San Francisco. Another nine people died under different circumstances. Of the total of 63 deaths, 57 were caused directly by the earthquake, and 6 others were ruled to have been caused indirectly. Additionally, there were 3,757 related injuries, 400 of which were serious. The quake caused an estimated $6 billion (1989 USD; $11.6 billion 2016 USD) in property damage, making it one of the costliest natural disasters in US history at the time.
The 1990 Rudbar Earthquake The 1990 Rudbar Earthquake, with a magnitude of 7.4, occurred in northern Iran on June 21, 1990, at 12:30 AM local time. The main shock was followed by numerous aftershocks. The earthquake, which was the largest ever to be recorded in that part of the Caspian Sea region, may have been amplified by two or more closely spaced earthquakes occurring in rapid succession. The event, which for this region was exceptionally close to the ground surface, was unusually destructive. Maximum surface displacements were 0.6 inches horizontally and 37 inches vertically. 135
Earthquakes occur in this region because Iran is compressed by Africa and the Arabian Peninsula, which is moving towards Eurasia at about 0.6 inches per year. The epicenter of this particular earthquake was located in the collision zone between the Arabian Plate and the Eurasian Plate. Widespread damage occurred to the northwest of the capital city of Tehran, including the destruction of the cities of Rudbar, Manjil, and Lushan, as well as 700 villages. In towns along one 80-mile stretch, every single building was reduced to rubble and every person there was killed. Additionally, a burst dam in Rasht, caused by a 6.5-magnitude aftershock the following morning, wiped out a large stretch of farmland. Rescue operations were hampered by several factors: the earthquake occurred in the middle of the night, weather conditions were adverse, and the villages were located in rugged mountainous terrain. Roads and highways were blocked by extensive landslides, 1990 Rudbar Dealing with The Dead further hampering rescue operations, and many of the people who initially survived under the rubble could not be rescued before their air supply ran out. The quake killed approximately 40,000 people and left 500,000 homeless. An estimated $8 billion (1990 USD; $14.7 billion 2016 USD) in damages occurred in the affected area.
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Chapter 13
Selected 21st Century Earthquakes Less than 20 years into the 21st century, there have already been seven extraordinarily deadly earthquakes worldwide, each with a death toll in excess of 20,000. Whether these quakes are indicative of a trend (perhaps exacerbated by humans) or are just part of a natural seismic cycle is uncertain. Of these, I have selected five for profiling below:
The 2004 Sumatra Earthquake The 2004 Sumatra Earthquake, with a magnitude of 9.2, occurred on December 26, 2004, at 7:58 AM local time, off the west coast of Sumatra, Indonesia, in the Indian Ocean. It is the third-largest earthquake ever recorded on a seismograph, and had the longest duration of faulting ever observed—between 8.3 and 10 minutes. The earthquake and its resultant tsunami was one of the deadliest natural disasters in recorded history. The earthquake itself, after the 1960 Valdivia quake and the 1964 137
Alaska quake, was the third-most-powerful earthquake recorded since 1900. This undersea megathrust earthquake was caused by the Indian Plate being subducted by the Burma Plate. An estimated 1,000 miles of fault surface slipped (or ruptured) about 50 feet along the subduction zone. The quake’s epicenter was between Simeulue and mainland Indonesia. The hypocenter of the main earthquake was approximately 100 miles off the western coast of northern Sumatra, in the Indian Ocean, at a depth of 19 miles below mean sea level. The slip did not happen instantaneously; it took place in two phases over a period of several minutes. As well as the sideways movement between the plates, the sea floor is estimated to have risen by several yards, displacing an estimated 7.2 cubic miles of water and triggering devastating tsunami waves. The raising of the sea floor significantly reduced the capacity of the Indian Ocean, producing a permanent rise in the global sea level by an estimated 0.004 inches. The total energy released by the quake—the vast majority of it underground—was equivalent to 9,600 gigatons of TNT (550 million times that of the Hiroshima atomic bomb), or about 370 years of energy use in the United States at 2005 levels. The earthquake generated a seismic oscillation of the Earth’s surface of as much as 8 to 12 inches, and the seismic waves were felt across the planet, even as far away as Oklahoma, where vertical movements of 0.12 inches were recorded. It caused the entire planet to vibrate about 0.4 inches and triggered other earthquakes as far away as Alaska. The shift of mass and the enormous release of energy very slightly altered the Earth’s rotation. While the exact amount is not yet known, theoretical models suggest that it shortened the length of a day by 2.68 microseconds, due to a decrease in the oblateness of the Earth. It also caused the 138
Earth to minutely “wobble” on its axis by up to 1 inch in the direction of 145° east longitude. The sudden vertical rise of the seabed by several yards during the earthquake displaced massive volumes of water, resulting in a tsunami that struck the various coasts of the Indian Ocean. The tsunami was the primary cause of the high death toll. Within 15 minutes, tsunami waves were crashing ashore on Sumatra. At Aceh, those waves reached 80 feet high over large stretches of the coast and up to 100 feet high in some places, while traveling as far as 1.2 miles inland. Entire communities were simply swept away by the water in a matter of minutes. The huge waves missed the north coast of Indonesia, then went on to Thai2004 Sumatra Tsunami land, where between 5,000 and 8,000 people died. The tsunami also moved east across the Indian Ocean. In Sri Lanka, it came ashore about 90 minutes after the earthquake, and approximately 35,000 people there lost their lives. In addition, about 15,000 people died in India. The killer waves even reached 5,000 miles away in South Africa, where two people perished. In Sri Lanka, the Matara Express (known locally as the “Queen of the Sea”), a passenger train out of Colombo, was derailed and overturned by the tsunami. At 9:30 AM local time, the first of the huge waves thrown up by the earthquake came ashore. The train, only 660 feet inland from the sea at the time, came to a halt as water surged around it. Hundreds of locals, believing the train to be secure on the rails, climbed onto the top of the cars to avoid being swept away. Others stood behind the 139
train, hoping it would shield them from the force of the water. The first wave flooded the carriages and caused panic among the passengers. Ten minutes later, a gigantic wave picked up the train and smashed it against the trees and houses that lined the track, crushing those seeking shelter behind it. The eight carriages were so packed with people that the doors could not be opened while they filled with water, drowning almost everyone inside as the water washed over the wreckage several more times. The passengers on top of the train were thrown clear of the overturned carriages, and most drowned or were crushed by debris. It has been estimated that the second tsunami wave was more than 100 feet high, rushing 2–4 feet over the top of the train. By death toll, this was the largest single railway disaster in history, with 1,700 or more lives being lost.† The total death toll for the earthquake and tsunami was approximately 230,000. The estimated financial damages were on the order of $10 billion (2004 USD; $12.7 billion 2016 USD).
The 2005 Kashmir Earthquake The 2005 Kashmir Earthquake, with a magnitude of 7.6, occurred on October 8, 2008, at 8:50 AM local time, in the Pakistani territory of Azad Kashmir. Its epicenter was about 12 miles northeast of Muzaffarabad, and 62 miles north-northeast of the national capital, Islamabad. In the 3 weeks following the main shock, there were about 1,000 aftershocks with a magnitude of 4.0 or more. Since then, measurements from satellites have shown that parts of the mountains directly above the epicenter †
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For more information about the Sri Lanka railway disaster, see my book Transportation Disasters.
have risen by a few yards, providing ample proof that the Himalayas continue to rise and that this earthquake was a part of that process. Kashmir lies in the area of collision between the Eurasian and Indian tectonic plates. The geological activity born out of this collision, also responsible for the birth of the Himalayan mountain range, is the cause of unstable seismicity in the region. Most of the devastation that occurred was in northern Pakistan and Azad Kashmir. Muzaffarabad, the state capital, was hardest hit in terms of casualties and destruction—more 2005 Kashmir - Muzaffarabad than 70% of all casualDestruction ties were estimated to have occurred there. Hospitals, schools, and rescue services—including police and armed forces—were paralyzed. There was virtually no remaining infrastructure, and communication was severely impeded. The government appealed to survivors to come down to valleys and cities for relief, because bad weather, mountainous terrain, landslides, and blocked roads made it difficult for relief workers to reach each house and the winter snows were imminent. US military helicopters stationed in neighboring Afghanistan quickly flew aid into the devastated region. Five border crossing points were opened between India and Pakistan to facilitate the flow of humanitarian and medical aid to the affected region, and aid teams from different parts of Pakistan and around the world came to the region to assist relief efforts. 141
The death toll was estimated to be more than 87,000, with approximately 138,000 injured and over 3.5 million rendered homeless. Financial damages were estimated to be more than $5.4 billion (2005 USD; $6.6 billion 2016 USD).
The 2008 Sichuan Earthquake The 2008 Sichuan Earthquake, with a magnitude of 8.0, occurred on May 12, 2008, at 2:28 PM local time. The main shock lasted for about 2 minutes, with the majority of energy being released in the first 80 seconds. The earthquake’s epicenter was located 50 miles westnorthwest of Chengdu, the capital of Sichuan Province, with a focal depth of 12 miles. This was the deadliest quake to hit China since the 1976 Tangshan earthquake, which killed at least 240,000 people. Further casualties and damage were caused by strong aftershocks—some exceeding a magnitude of 6.0—which continued to hit the area for several months after the main quake. Between 64 and 104 major aftershocks, ranging in magnitude from 4.0 to 6.1, were recorded within 72 hours of the main quake. The earthquake was caused by the collision of the Indian-Australian and Eurasian plates along the 155-milelong Longmenshan Fault, a thrust fault in which the stresses produced by the northward-moving IndianAustralian Plate shifted a portion of the Plateau of Tibet eastward. Compressional forces brought on by this shift sheared the terrain in two locations along the fault, thrusting the ground upward by approximately 29 feet in some places. This is the best-known example of what is believed to be an earthquake precipitated by human activity—namely, the pressure caused by an artificial lake 142
created by the building of the Zipingpu Dam between 2001 and 2006 on the Min River near the city of Dujiangyan. All of the highways into Wenchuan County, and others throughout the province, were damaged, resulting in delayed arrival of the rescue forces. In Beichuan County, 80% of the buildings collapsed. In the city of Shifang, the collapse of two chemical plants led to leakage of some 80 tons of liquid ammonia, and hundreds of people were reported buried 2008 Sichuan alive. In the city of DujiBuilding Destruction angyan, an entire school collapsed, burying 900 students of which fewer than 60 survived. As a result of the earthquake and the numerous strong aftershocks, many rivers became blocked by large landslides, which resulted in the formation of “quake lakes” behind the blockages. The massive quantities of water pooling up at a very high rate behind these natural landslide dams caused fears that the blockages would eventually crumble under the weight of the ever-increasing water mass, potentially endangering the lives of millions of people living downstream. As of 2 weeks after the quake, 34 lakes had formed, and it was estimated that 28 of them were still a potential danger to the local people. Entire villages had to be evacuated because of the resultant flooding. More than 87,000 people lost their lives in the quake, 375,000 were injured, and about 4.8 million were left homeless. Estimated total damages exceeded $20 billion (2008 USD; $22.3 billion 2016 USD). 143
The 2010 Haiti Earthquake The 2010 Haiti Earthquake, with a magnitude of 7.0, struck on January 12, 2010, at 4:53 PM local time. Its epicenter was approximately 16 miles west of Port-auPrince, Haiti’s capital. The earthquake struck in the most populated area of the country, and shaking damage was more severe than for other quakes of similar magnitude due to the quake’s shallow depth (8.1 miles). When measured in terms of the number of people killed as a percentage of the country’s population, the earthquake was the most destructive event any country has experienced in modern times. In the 2 weeks following the main shock, there were about 52 aftershocks with a magnitude of 4.5 or greater. The quake occurred in the vicinity of the northern boundary where the Caribbean tectonic plate shifts eastwards by about 0.79 inches per year in relation to the North American plate. The strike-slip fault system in the region has two branches in Haiti, the SeptentrionalOriente Fault in the north and the Enriquillo-Plantain Garden Fault in the south. The earthquake’s location and focal mechanism both suggested that the earthquake was caused by a rupture of the Enriquillo-Plantain Garden Fault, which had been locked for 250 years, gathering stress. The rupture was roughly 40 miles long, with a mean slip of about 6 feet. The earthquake caused major damage in Port-auPrince, Jacmel, and other cities in the region. Notable landmark buildings were severely damaged or destroyed, including the Presidential Palace, the National Assembly building, and the Port-au-Prince Cathedral. The headquarters of the United Nations Stabilization Mission in 144
Haiti, located in the capital, collapsed, killing many. Part of the widespread devastation and damage throughout Port-au-Prince and elsewhere, vital infrastructure necessary to respond to the disaster was severely damaged or destroyed. This included all hospitals in the capital; air, sea, and land transport facilities; and communication systems. Almost immediately, Port-au-Prince’s morgue facilities were overwhelmed, and by January 14, 1,000 bodies had been placed on the streets and pavements. Government crews manned trucks to collect thousands more, burying them in mass graves. In the heat and humidity, corpses buried in rubble began to decompose and smell. The government buried many in 2010 Haiti - Uncollected Bodies mass graves, and some above-ground tombs were forced open so bodies could be stacked inside, while other bodies were burned. Tens of thousands of bodies were reported as having been brought to one mass burial site by dump truck and buried in trenches dug by earth movers. Impartial death toll estimates range from 100,000 to about 220,000, although the Haitian government placed the death count at 316,000, a number widely believed to be deliberately inflated. The best estimate appears to be on the order of 200,000. Estimates of financial damages range from $7 billion to $14 billion, with the most likely amount being about $10 billion (2010 USD; $11 billion 2016 USD).
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The 2011 Tohoku Earthquake The 2011 Tōhoku Earthquake, with a magnitude of 9.0, occurred off the Pacific coast of Japan on March 11, 2011, at 2:46 PM local time, with the primary shock lasting about 6 minutes. The epicenter of this undersea megathrust earthquake was located approximately 43 miles east of the Oshika Peninsula of Tōhoku, and the hypocenter was at an underwater depth of approximately 18 miles. The earthquake triggered powerful tsunami waves that reached heights of up to 133 feet and traveled inland for a distance of as much as 6 miles. It was the most powerful earthquake ever recorded in Japan, and the fourth-most-powerful earthquake in the world since modern record-keeping began in 1900. The main earthquake was preceded by a number of large foreshocks, and Japan has experienced over 1,000 aftershocks since the earthquake, with 80 registering over magnitude 6.0, and several with a magnitude of more than 7.0. This earthquake occurred where the Pacific Plate is subducting under the Eurasian Plate upon which Honshu Island sits. The break caused the sea floor to rise by several yards. A 250-mile stretch of coastline dropped vertically by 2 feet, allowing the tsunami to travel farther and faster onto land. The seabed in the area between the epicenter and the Japan Trench moved 160 feet east-southeast and rose about 23 feet as a result of the quake. The quake also caused several major landslides on the seabed in the affected area. It moved Honshu (the main island of Japan) 8 feet east, and shifted the Earth on its axis an estimated 4 to 10 inches. This deviation led to a number of small planetary changes, including the length of a day, the tilt of the Earth, and the “Chandler Wobble” (a small deviation in the Earth’s axis of rotation). The speed of the Earth’s rotation increased, shortening the day by 146
1.8 microseconds due to the redistribution of the Earth’s mass. The surface energy of the seismic waves from the earthquake was nearly double that of the 9.1-magnitude 2004 Indian Ocean earthquake and tsunami. The upthrust along a 180-mile-wide seabed 37 miles offshore from the east coast of Tōhoku resulted in a major tsunami that brought destruction along the Pacific coastline of Japan’s northern islands. The damage caused by the tsunami, though much more localized, was far more deadly and destructive than the earthquake itself. The tsunami inundated a total area of approximately 217 square miles in Japan, and thousands of lives were lost when entire towns were devastated by the waves. Among several factors causing the high death toll from the tsunami, one was the unexpectedly large size of the water surge. Although Japan had spent the equivalent of billions of US dollars on antitsunami seawalls, which line at least 40% of its 21,593- mile coastline and stand up to 39 feet 2011 Tohoku high, the tsunami simply Tsunami Overtopping Seawall washed over the top of many of them, collapsing some in the process. More than 100 designated tsunami evacuation sites were inundated by the onslaught of water. The tsunami propagated throughout the Pacific Ocean region reached the entire Pacific Coast of North and South America, from Alaska to Chile, but the extent of the damage there was relatively minor. Chile’s Pacific Coast, about 11,000 miles from Japan, was struck by waves 6.6 feet high. In California and Oregon, tsunami surges up to 7.9 feet tall hit some areas, damaging docks 147
and harbors and causing several million dollars in damage. The tsunami also broke icebergs off the Sulzberger Ice Shelf in Antarctica, 8,100 miles away; a total of 48 square miles of ice broke away, with the main iceberg measuring 5.9 miles × 4.0 miles (approximately the area of Manhattan Island) and about 260 feet thick. The Japanese government estimated that the tsunami swept about 5 million tons of debris offshore, claiming that 70% sank, leaving 1.5 million tons floating in the Pacific Ocean. Some of this wreckage has come ashore, including a soccer ball that was found in Alaska and a Japanese motorcycle found in British Columbia. In 2012, the US Coast Guard came across a derelict ship, the 164foot Ryou-Un Maru, in the Gulf of Alaska, which it sank with gunfire. The tsunami caused several nuclear accidents, primarily the level-7 (major) meltdowns at three reactors in the Fukushima Daiichi Nuclear Power Plant complex, whose associated evacuations involved hundreds of thousands of residents. Many electrical generators were taken down, reducing total generating capacity by 21 GW; and at least three nuclear reactors suffered explosions with radioactive leakage after cooling system failures caused by the loss of electrical power when the emergency diesel generators were disabled by the tsunami. All told, about 4.4 million households were left without electricity. Approximately 20,000 people died or went missing as a result of the Tohoku event. The financial cost of the earthquake and tsunami combined has been estimated to be about $235 billion USD. While this figure may seem extreme when compared to the costs of other earthquakes, there are three important factors that must be taken into account: (1) A disaster in a highly developed area will cause considerably more destruction than one in an area 148
that is less developed; (2) The cost of any specific type of structure is considerably more than it was even as little as a decade or two ago; and (3) Special-purpose modern structures, such as nuclear power plants (which cost about $9 billion USD each), can be extremely costly. Other natural disasters that were comparable in terms of damages—all of them hurricanes, and all of them recent—include: Hurricane Katrina in 2005 ($134 billion USD); Hurricane Harvey in 2017 ($180 billion USD); and Hurricane Irma in 2017 ($200 billion USD). Most likely, the Tohoku earthquake/tsunami was the costliest natural disaster ever.
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Chapter 14
What’s Next? Earthquakes have always been with us, and presumably always will. There is currently no known way of preventing an earthquake, and none is likely ever to be found. Earthquakes can strike any location at any time, but history shows they occur in the same general patterns over time, principally in the three large zones of the Earth discussed in Chapter 1.
Earthquake Risk The world’s greatest earthquake zone, the CircumPacific Seismic Belt (often spoken of as “The Ring of Fire”), is located along the rim of the Pacific Ocean, and it is where about 81 percent of the world’s largest earthquakes occur. The second important belt, the Alpide, which extends from the Indian Ocean through the mountains of Southeast Asia, the Mediterranean, the mountains of Southern Europe, and out into the Atlantic Ocean—accounts for approximately 17 percent of the world’s largest earthquakes, including some of the most destructive. The third prominent belt follows the sub150
merged Mid-Atlantic Ridge. The remaining shocks are scattered in various areas of the world. Earthquakes in these prominent seismic zones are taken for granted, but damaging shocks also occur infrequently outside these areas. With the rapid growth of mega-cities such as Mexico City, Tokyo, and Tehran in areas of high seismic risk, some seismologists are warning that a single quake may claim the lives of up to 3 million people. Worldwide, some specific locales are at very high risk for major earthquakes, but most places are subject to little or no risk. The 10 countries with the highest risk levels (ordered from least risk to greatest risk) are: 10. Indonesia: This country is in the zone where the Indian Plate is being subducted under the Burma Plate. Jakarta, the capital of Indonesia, occupies a very precarious position; not only is it situated atop the Pacific Ring of Fire, but also, almost half of the city is below sea level, putting it on soft soil that has the potential to liquefy. 9. Turkey: Turkey is located within the seismic zone between the Arabian, Eurasian, and African plates. Its geographic location suggests that an earthquake can hit the country at any time. 8. Mexico: This earthquake-prone country has experienced several earthquakes of high magnitudes in the past. It is situated atop three of the world’s large tectonic plates, namely, the Cocos Plate, the Pacific Plate, and the North American Plate. Mexico is one of the most seismologically active regions on Earth. 7. El Salvador: This small Central American republic has experienced, on average, one destructive earthquake per decade during the last 100 years. 151
The earthquakes have clearly demonstrated trends of increasing seismic risk in El Salvador due to rapid population expansion in areas of high shaking and landslide hazard, aggravated by deforestation and uncontrolled urbanization. 6. Pakistan: Pakistan is geologically located in the Indus-Tsangpo Suture Zone, which is roughly 125 miles north of the Himalaya Front. This region has the highest rates of seismicity and the largest earthquakes in the Himalaya region, caused mainly by movement on thrust faults. 5. The Philippines: This island state lies on the edge of the Pacific Plate, a traditional seismic hot zone, which encircles the country. The capital, Manila, is very much at risk because, being located on the Pacific Ring of Fire, it is susceptible not only to quakes, but also to volcanic eruptions. Moreover, the threat to the city is exacerbated by its soft soil, which presents the risk of ground liquefaction. 4. Ecuador: This South American country lies within the seismic zone between the South American Plate and the Nazca Plate. Ecuador has several active volcanoes, which can cause high-magnitude quakes and tremors. Thus, there are two types of sources for earthquakes: (1) those that result from movement on the subduction interface along the plate boundary; and (2) those that are associated with active volcanoes. 3. India: India has experienced multiple deadly earthquakes due to the Indian Plate driving into the Eurasian Plate at the rate of 1.8 inches every year. 152
2. Nepal: This is a disaster-prone country with floods, landslides, epidemics, and fires that cause considerable loss of life and property every year. It is one of the most seismically active regions in the world as a result of the Indian Plate driving under Central Asia; its tectonic activity is responsible for the creation of the Himalayan mountains. Moreover, the remnants of a prehistoric lake, a 900-foot-deep layer of black clay, lies underneath the Kathmandu Valley and makes it susceptible to soil liquefaction. 1. Japan: Japan tops the list of the earthquakeprone areas, primarily as a result of the subduction of the Philippine Sea Plate beneath the Okinawa Plate and Amurian Plate. The country, with its location on the Pacific Ring of Fire, is highly susceptible not only to earthquakes, but also to tsunamis and volcanic eruptions.
The 10 states in the United States with the greatest frequency of earthquake are (listed in order from the lowest to the highest) are: (10) Oregon; (9) Utah; (8) Montana; (7) Wyoming; (6) Idaho; (5) Washington; (4) Nevada; (3) Hawaii; (2) California; and (1) Alaska. The highest-risk cities in the country are Los Angeles and San Francisco. Alaska, which has an average of 1,000 earthquakes per month, most of them small, is one of the most seismically active regions in the world. The active geology of Alaska guarantees that major damaging earthquakes will continue to occur. In 1964, the state was the site of the second-largest earthquake ever recorded in the world and 153
has reported 11% of the world’s recorded earthquakes. Of the 10 largest historical earthquakes in the US, 7 have been in Alaska, and 1 earthquake with a magnitude of 8.0 or larger has occurred every 13 years since 1900. California has more than 300 fault lines crossing the state. Particularly at risk is the southern part of the San Andreas Fault, which runs close to Los Angeles and has remained quiet since a magnitude-7.9 earthquake in 1857. Enormous amounts of pressure have built up along that fault line, and both the San Francisco Bay and Los Angeles areas are now extremely vulnerable. The US Geological Survey (USGS) has stated that the probability that a magnitude-8.0 or larger earthquake will hit California has increased within the last few years, and it is only a matter of time before the “Big One”—the megaquake that Californians have been fearing for some time—strikes.
Golden Gate Tsunami Nightmare (Artist’s Rendering)
According to the USGS, Hawaii experiences thousands of earthquakes each year due to the eruptive forces within its active volcanoes, as well as the weight of the islands causing structural changes beneath the Earth’s 154
crust. While most of the earthquakes are small, some are large enough to cause significant damage. The US Pacific Northwest is bracing for a major earthquake and tsunami as pressure has built up in the zone since the 1700s. The possible source of this catastrophic event is the Kilauea Volcano - Hawaii Cascadia Subduction Zone, an 800-mile crack in the Earth’s crust located 60 miles offshore from Oregon. The Juan de Fuca Plate and North American Plate create this subduction zone, which is considered the quietest subduction zone in the world, but is currently thought to be harboring one of the biggest seismic events of the century. The eventual earthquake could measure at a magnitude of 9+. Once the earthquake hits, cities like Seattle and Portland will bear the brunt of the earthquake in human fatalities because they are more densely populated than the surrounding regions. Away from the US coasts and toward the Midwest and South, lies the New Madrid Seismic Zone, which puts states including Missouri, Illinois, Kentucky, Tennessee, Indiana, and Arkansas at risk for a destructive earthquake. St. Louis and Memphis already saw damaging earthquakes in the 1800s. The New Madrid Fault System can also affect Mississippi and Oklahoma. Oklahoma, in particular, has seen a rising risk for induced seismicity as a result of human activity. These mostly minor earthquakes, caused by the injection of fluids into deep wells for waste disposal and secondary recovery of oil been documented there and elsewhere in the US—primarily in Colorado, Texas, Arkansas, and 155
Ohio—as well as in Japan, and Canada. Deep mining can cause small-to-moderate quakes, and nuclear testing has caused small earthquakes in the immediate area surrounding the test site. However, other human activities have not been shown to trigger subsequent earthquakes. Within the central and eastern United States, the number of earthquakes has increased dramatically over the past few years. Between 1973 and 2008, there was an average of 21 earthquakes of magnitude 3+ annually. This rate jumped to 99 per year in the period from 2009 to 2013, and the rate continues to rise. In 2014 alone, there were 659 magnitude-3+ earthquakes. Most of these earthquakes were in the magnitude-3 to -4 range— large enough to have been felt by many people, yet small enough that they rarely caused damage. There were reports of damage from some of the larger events in 2011, including a magnitude-5.6 quake in Prague, Oklahoma, and a magnitude-5.3 quake in Trinidad, Colorado.
Earthquake Prediction The likelihood that the US will see a catastrophic earthquake within the next 30 years is very high. There is no way to predict the time of its occurrence, but that it will happen is almost certain. As long as the tectonic plates keep moving and time passes without an earthquake, the pressure along fault lines will continue to build until eventually it must be released by a quake. Seismologists have long warned that the US is “overdue” for an earthquake because a catastrophic one has not occurred in the country since 1989, when the Loma Prieta earthquake killed at least 63 people in California. The most destructive earthquake ever in the US was the 7.9-magnitude San Francisco Earthquake of 1906, 156
which killed an estimated 3,000 people. As more years have passed without earthquakes, pressure has built up along certain fault lines when tectonic plates are unable to shift. In the 1970s, scientists were optimistic that a practical method for predicting earthquakes—the location, time, and magnitude—would soon be found. Research into prediction methodologies centered around possible precursors—anomalous phenomena that might give effective warning of an impending quake. There have been around 400 scientific literature reports of possible precursors—although they are generally recognized as such only after the event—of roughly 20 different types, running the gamut from aeronomy to zoology. Some of these are: anomalous animal behavior; electrical, electrical resistivity, and magnetic changes in crystalline rock when it is stressed; changes in primary and secondary seismic wave velocity when travelling through rock under stress; and stress release of radon gas. None of these “precursors” has proven to be a valid predictor of earthquakes. By the 1990s, continuing failures led many to question whether earthquake prediction was even possible. Demonstrably successful predictions of large earthquakes have not occurred, and the few claims of success are controversial. There is currently no scientifically plausible way of predicting the occurrence of a particular earthquake. The USGS can and does make statements about earthquake rates, describing the places most likely to produce earthquakes in the long term. Although many believe effective earthquake prediction is possible, doubters suggest otherwise, as it has yet to be demonstrated. Given that the purpose of short-term prediction is to enable emergency measures to reduce death and destruction, failure to give warning of a major earthquake 157
that does occur—or at least an adequate evaluation of the hazard—can result in legal liability, or even political purging of those who are considered to be responsible. But warning of an earthquake that does not occur also incurs a cost—not only of the emergency measures themselves, but of civil and economic disruption. False alarms—including alarms that are canceled— also undermine the credibility, and thereby the effectiveness, of future warnings. The acceptable trade-off between missed quakes and false alarms depends on the societal valuation of these outcomes. The rate of occurrence of both must be considered when evaluating any prediction method. Even a (hypothetically) excellent prediction method might be of questionable social utility, because organized evacuation of urban centers is unlikely to be successfully accomplished, while panic and other undesirable side-effects can be anticipated. Earthquake prediction is sometimes distinguished from earthquake forecasting, which can be defined as the probabilistic assessment of general earthquake hazard, including the frequency and magnitude of damaging earthquakes in a given area over years or decades. Rather than using “precursor” methods, forecasting generally uses probabilistic “trend” or “patterns” methods in its attempt to successfully achieve its objectives. As these trends may be complex and involve many variables, advanced statistical techniques are often needed to understand them; therefore, these are sometimes called “statistical” methods. Forecasting is likely to have more success than predicting because its goals do not require the same degree of specificity. Forecasting methodologies are generally grounded in the elastic rebound theory of earthquake causation, which holds that when tectonic plates move past each other, the Earth’s crust bends or deforms because of 158
the great strain to which it is subjected, and eventually something fractures, usually at an existing fault. This release of strain allows the deformed rock to rebound to a less deformed state and is accompanied by the release of enormous amounts of energy in various forms, including seismic waves. This cycle is then repeated, and a pattern develops from which long-range forecasts can be made. The characteristic earthquake model postulates that earthquakes are generally constrained within the individual segments of a fault, and that earthquakes that rupture the entire fault should have similar characteristics. Given that tectonic plate motions are continuous and cause the strain to accumulate steadily, seismic activity on a specific segment is likely to involve a pattern that recurs at quasi-regular intervals, thus informing us about the next rupture. The seismic gap model suggests that when two tectonic plates slide past one another, every segment must eventually slip so that, in the long term, none gets left behind. The segments, however, do not all slip at the same time, so this lack of simultaneity means that different sections will be at different stages of deformation and rebound. This means that the “next big quake” should be expected not in the segments where recent seismic activity has occurred, but in those where the strain has continued to accumulate. The time of increased probability model is grounded in the premise that, within a given area, certain patterns of small earthquakes can provide advance notice of the occurrence of a large earthquake to follow. The accelerating moment release model is based on observations that foreshock activity prior to a major earthquake not only increases, but increases at an exponential rate. When that rate of increase accelerates rapidly, it likely indicates that a major earthquake will occur in the near future. Each of these models has a certain intuitive appeal, but as all have both weaknesses and 159
strengths, no single one alone has proven to be a highly effective tool for forecasting. Taken collectively, however, they serve as a useful means whereby seismologists can make educated guesses as to what seismic activity can be anticipated in the mid- to long-term future. Such guesses (“estimates”) can then be used to establish building codes, insurance rate structures, awareness and preparedness programs, and public policy related to seismic events. Both prediction and forecasting of earthquakes are distinguished from earthquake warning systems, which, upon detection of an earthquake, provide a real-time warning to regions likely to be affected. An earthquake warning system is a system of accelerometers, seismometers, communication, computers, and alarms that is devised for regional notification of a substantial earthquake while it is in progress. Such a system works by detecting seismic pressure (or primary) waves that radiate outward from the rupturing fault at a speed faster than that of the much more destructive seismic shear (or secondary) waves, thus being able to provide a few moments’ notice before the arrival of the shear waves. The pressure wave generates an abrupt shock while the shear waves generate a low-frequency periodic motion that is highly destructive of structures, particularly buildings that have a similar resonant period, typically those that are 6 to 15 stories tall. The earliest automated earthquake pre-detection systems were installed in the 1990s. As of 2016, both Japan and Taiwan have comprehensive nationwide earthquake early warning systems. Other countries and regions have partial deployment of earthquake warning systems, including Mexico, some regions of Romania, and parts of the United States.
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Earthquake Mitigation While it is clear that nothing can be done to prevent earthquakes, that does not mean that we are totally helpless in dealing with them. Much can be done to prepare for an earthquake, and much can be done to mitigate its effects once it strikes. Below is an outline of useful actions people can take before, during, and after an earthquake. For much greater specificity, see the website: https://www.wikihow.com/Prepare-for-an-Earthquake. BEFORE AN EARTHQUAKE: • Prepare Your Home to Minimize Damage: ○○ Fasten any large items securely to the walls and floor. ○○ Install shatter-safe window films for protections from breaking glass. ○○ Place breakable items (bottles, glass, china, etc.) in closed cabinets that have latches. ○○ Remove or secure hanging objects from the space above seating and sleeping areas. ○○ Check with a professional, your landlord, or the zoning board to confirm that your house is up-to-date with earthquake protections. • Prepare an Emergency Plan: ○○ Identify the best places for cover and protection in your building. ○○ Teach everyone how to signal for help if trapped. ○○ Learn how to turn off the utilities in your house, especially the gas line. ○○ Practice “Drop, Cover, and Hold On.” (See below.) ○○ Learn basic first aid and CPR. ○○ Determine a rallying point where your family 161
•
can reunite after the earthquake. ○○ Research routes and methods for getting home after an earthquake. ○○ Write down and share emergency contact lists. ○○ Work with your community to find resources for preparation. Prepare an Emergency Kit: ○○ Purchase enough emergency non-perishable food and water for at least 3 days. Have on hand 1 gallon of water per day for each person, plus a few more for emergencies. Include a manual can opener for opening emergency rations. ○○ Buy a solar or manual crank flashlight and radio, or a regular flashlight with extra batteries. Also buy a whistle for signaling. ○○ Create (or purchase) a comprehensive first aid kit. ○○ Assemble a basic tool kit that can help you get out of the house if necessary. ○○ Include those supplies needed to make an emergency stay—e.g., at a shelter—more comfortable.
DURING AN EARTHQUAKE: • If you are inside a building, stay there. Use the “Drop, Cover, and Hold On” method. Drop to the floor, make yourself as small possible, cover your head and neck with your arms and hands, and get under a desk or table to which you can hold on, or stand in a corner. If you are in bed, stay there and cover your head and neck with a pillow. If you are in a high-rise building, stay away from 162
•
•
windows and outside walls, stay out of elevators, and get under a table. If you are outdoors, move away from buildings, streetlights, and utility wires. Once in the open, “Drop, Cover, and Hold On.” Stay there until the shaking stops. If you are driving, pull over to the side of the road and stop as quickly and safely as possible; stay in the vehicle. Avoid stopping near or under buildings, trees, overpasses, and utility wires.
AFTER AN EARTHQUAKE: • Check your surroundings when the shaking stops. If you are in a building that is damaged and there is a clear path to safety, leave the building and go to an open space away from damaged areas. • If you are trapped, do not move about or stir up dust. • If you have a cell phone with you, use it to call or text for help. • Make noise by banging on a pipe or wall, or by using a whistle, if you have one, so that rescuers can locate you. • Once safe, monitor local news reports via battery-operated radio, television, social media, and cell phone text alerts for emergency information and instructions. • Check for injured people and provide assistance if you have training. Assist with rescues if you can do so safely.
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164
Appendix A Comparative Data— Selected Earthquakes Year Earthquake Country Mag-nitude Tsunami Event Height (ft)
Deaths
Damage (2016 BUS$)
365
Crete
Roman Empire
8.6
100
N/A
N/A
1138
Aleppo
Syria
8.5
N/A
230,000
N/A
1498
Nankai
Japan
8.6
56
31,000
N/A
1556
Shaanxi
China
8
N/A
825,000
N/A
1693
Sicily
Italy
7.4
25
60,000
N/A
1707
Hoei
Japan
8.6
33
5,000
N/A
1755
Lisbon
Portugal
8.5
66
50,000
N/A
1868
Arica
Chile
8.7
52
25,000
4.8
1896
Sanriku
1906 San Francisco
Japan
8.5
125
22,000
N/A
United States
7.8
N/A
3,000
10.1
1908
Messina
Italy
7.5
39
120,000
N/A
1920
Haiyuan
China
7.8
N/A
273,000
1.3
1923
Kanto
Japan
7.9
39
143,000
14.0
1960
Valdiva
Chile
9.5
82
3,500
4.8
1964
Alaska
United States
9.2
220
139
2.4
1970
Ancash
Peru
7.9
1
70,000
3.1
1976
Tangshan
China
8.0
N/A
242,000
6.3
1985 Mexico City
Mexico
8.0
10
10,000
7.8
1989 Loma Prieta
United States
6.9
N/A
63
11.1
1990
Rudbar
Iran
7.4
N/A
40,000
14.7
2004
Sumatra
Indonesia
9.2
100
230,000
12.7
2005
Kashmir
Pakistan
7.6
N/A
87,000
6.6
2008
Sichuan
China
8.0
N/A
88,000
22.3
2010
Haiti
Haiti
7.0
N/A
200,000
11.0
2011
Tohoku
Japan
9.0
133
20,000
235.0
165
166
Section IV
Big Waters Rolling
167
Chapter 15
Floods in General The lore of many cultures around the world prominently features the story of a catastrophic “Great Flood” that essentially destroyed all of the civilized world. The version that westerners are most familiar with, of course, is that in the Book of Genesis in the Hebrew Bible. That version closely parallels the Mesopotamian version found in a 700 BC Babylonian copy of the Epic The Great Flood of Gilgamesh. Similar stories exist in Greek, Hindu, and Norse mythology, as well as with the peoples of Mesoamerica, some tribes of Native North Americans, various groups in South America, and the Aboriginal tribes in southern Australia. A worldwide deluge, such as described in Genesis, is incompatible with modern scientific understanding of natural history, so we have characterized these stories as being myths. During the epoch that followed the end of the last glacial period (approximately 11,700 years ago), there were any number of localized “megafloods” 168
that were of such magnitude that the people who experienced them, lacking a true world perspective, would presumably have believed that the whole world had been destroyed. The human population of the world 12,000 years ago was only about 4,000,000, so in light of the fact that the Yangtze-Huai River Floods of 1931 killed 1–4 million people, it is not far-fetched to think that one or more of those megafloods killed off a large percentage of the then-existing population if it struck in a populated area. The floods that are known to us through historical descriptions are mostly related to meteorological events, such as heavy rains, rapid melting of snowpacks, or combinations of these. These floods involved rates of water flow much greater than those in the historical record. In central North America, for example, enormous “proglacial” lakes formed, and their drainage patterns shifted frequently with the forming and melting of ice dams. The most famous of these was Lake Agassiz. As ice-dam configurations failed, a series of “glacial lake outburst floods,” catastrophic at times, were released. It is believed that the most noteworthy of these floods occurred approximately 13,000, 10,000, and 8,000 years ago. There are a number of other potential candidates for being the historical bases for these beliefs. Among them, two that are especially likely because they occurred close to the center of civilization at the time are: • The Black Sea Deluge hypothesis: As sea levels rose (about 400 feet) with the retreat of the glaciers, waters from the Mediterranean Sea breached a sill in the Bosporus Strait about 7,600 years ago. The event flooded 60,000 square miles of land and significantly expanded the Black Sea shoreline to the north and west. It is estimated 169
that 10 cubic miles of water poured through the breach each day (200 times the flow of Niagara Falls) for a period of at least 300 days. •
The volcanic eruption of Thera: Thera (now called Santorini), an island in the southern Aegean Sea, was devastated by an enormous volcanic eruption about 3,600 years ago. It was one of the largest eruptions on Earth in recorded history and expelled approximately 15 cubic miles of magma and rock into the atmosphere. That fiery explosion killed upwards of 40,000 people, produced colossal tsunamis more than 40 feet tall, spewed volcanic ash across Asia, and caused a significant drop in global temperatures. It also caused apocalyptic rainstorms in Egypt. The ash, tsunami, and a related earthquake affected coastal towns on the island of Crete, and ultimately led to the end of the Minoan civilization, which had been the dominant power in the Mediterranean.
The simplest definition of a flood is “an event that occurs when water overflows or inundates land that is normally dry.” There are a number of ways in which this can happen, the most common being when rivers or streams overflow their banks. Floods are generally classified according to the likelihood of their occurrence in a given time period. A 100-year flood, for example, is an extremely large, destructive event that would theoretically be expected to happen only once every century; but this is only a theoretical number. In reality, this classification means there is a 1 percent chance that such a flood could happen in any given year. Over recent decades, possibly due to global climate change, 100-year floods have been occurring worldwide with frightening regular170
ity. There are three basic types of floods: surface floods, riverine floods, and coastal floods. • Surface Flood: A surface water flood is caused when heavy rainfall creates a flood event independent of an overflowing body of water. It is a misconception that floods occur only near a body of water. A surface flood occurs in flat or lowlying areas when water is generated by rainfall or snowmelt more rapidly than it can be either absorbed or run off. Absorption can be hindered or prevented by saturated soil, frozen ground, Surface Flood rock, concrete, paving, or roofs. Surface flooding that is caused by an overwhelmed urban drainage system, with water flowing out into streets and nearby structures, is spoken of as “urban flooding.” Although the water in an urban flood is usually only a few inches deep, it can cause considerable property damage, seeping through building walls and floors or backing up into buildings through sewer pipes, toilets, and sinks. •
Riverine Flood: A riverine flood is what most people think of when they hear the word “flood.” Filled to capacity because of heavy rain or melting snow, the water within a river overflows its banks (“overbank flooding”) and spreads across the land around it. Such a flood can occur in all types of river and stream channels, from the smallest ephemeral streams in humid zones, to normally 171
dry channels in arid climates, to the world’s largest rivers. The primary factors affecting flood magnitude are catchment area, House Surrounded by Overbank Floodwater precipitation intensity, channel slope, and channel profile. Slowrising floods most commonly occur in large rivers with sizeable catchment areas. Large rivers may also have rapid flooding events in areas with dry climates, because they may have large basins but small river channels, and rainfall can be very intense in smaller areas of those basins. Rapid flooding events, including flash floods, more often occur on smaller rivers, rivers with steep valleys, rivers that flow for much of their length over impermeable terrain, or normally dry channels in arid zones. The cause may be localized intense thunderstorms or sudden release from an upstream imFlash Flood poundment created behind a dam, landslide, ice jam (“ice jam flooding”), or glacier. Flash flooding is characterized by an intense, high-velocity torrent of water that occurs in an existing river channel with little to no notice. Flash floods are very dangerous and destructive not only because of the force of the water, but also the hurtling debris that is often 172
swept up in the flow. Fast-moving water is extremely dangerous; water moving at 10 miles an hour can exert the same pressures as wind gusts of 270 miles per hour. Areas damaged by wildfires are particularly susceptible to flash floods and debris flows during rainstorms; rainfall that is normally absorbed by vegetation can run off almost instantly, causing creeks and drainage areas to flood much more quickly and with higher magnitude than normal. Catastrophic riverine floods are usually associated with major infrastructure failures such as the collapse of a dam, but they may also be caused by drainage channel alterations from landslides, earthquakes, or volcanic eruptions. •
Coastal Flood: Coastal flooding occurs along the edges of oceans, and is driven predominantly by storm surges, waves, and low atmospheric pressure. A storm surge is an abnormal rise of water generated by a storm, one that is over and above the predicted astronomical tides. This rise in water level can cause extreme flooding in coastal areas—particularly when the Storm Surge storm surge coincides with normal high tide, resulting in storm tides reaching up to 20 feet or more in some cases. This kind of flooding is usually connected to hurricanes or tropical storms. Along the coast, storm surge is often the greatest threat to life and property from a hurricane; in a hurricane, 9 out 173
of 10 deaths are caused not by wind but by fastmoving storm surge. Catastrophic coastal flooding can also be caused by tsunamis. A tsunami is a series of waves in a large body of water caused by the displacement of a significant volume of water, usually as a result of an earthquake or volcanic eruption, and sometimes a landslide, glacier calving, or meteorite impact. Tsunamis, which can strike with little or no warning, typically reach a height of 30 feet, sometimes much more, causing enormous damage and loss of life. Floods can have negative consequences—generally, the bigger the flood, the worse the consequences. The primary effects of flooding include loss of life and Tsunami damage to buildings and other structures—including bridges, sewerage systems, roadways, and canals. Floods also frequently damage power transmission and sometimes power-generation infrastructures, causing loss of power, which can then result in the loss of drinking water treatment and water supply facilities or severe water contamination. They may also cause the loss of sewage disposal capabilities. Lack of clean water, combined with human sewage in the flood waters raises the risk of waterborne diseases and many others, depending upon the location of the flood. Flood waters typically inundate farm land, making the land unworkable and preventing crops from being planted or harvested, which can lead to shortages of food both for humans and farm animals. 174
Not all flood consequences, however, are negative. Floods, especially fresh-water floods, can also bring many benefits, such as recharging ground water, making soil more fertile, and increasing soil nutrients. They can spread nutrients to lakes and rivers, leading to increased biomass and improved fisheries for a few years. Moreover, floods— both fresh-water and salt-water—play an important role in maintaining ecosystems and biodiversity in the areas that they affect.
175
Chapter 16
The Worst Riverine Floods in World History Riverine floods are the most common type of floods. Their negative consequences, however, can often be exceeded by those of coastal floods, which are usually caused by hurricanes or tsunamis in which a major portion of fatalities and damages are the result of event-related factors other than flooding. Because the differentiation is often impossible to make, I have chosen to present the different types of floods separately. Riverine floods are covered in this and the following chapter. Coastal floods are discussed later. In contemporary historical times, significant riverine floods have frequently killed thousands of people, but generally less than a million. Most of the world’s deadliest historical floods have occurred in China, but the low-lying Netherlands has been particularly hard hit as well. A list of the 10-deadliest riverine floods in world history is presented below, and a discussion of each then follows.
176
Deadliest Riverine Floods in World History Rank Fatalities Event Location (thousands) St. Marcellus 10 36 Netherlands Flood 9 50–80 St. Lucia’s Flood Netherlands Yangtze River 8 100 China Flood Red River Delta 7 100 North Vietnam Flood 6 100+ St. Felix’s Flood Netherlands Yangtze River 5 145 China Flood Banqiao Dam 4 231 China Failure Yellow River 3 500–800 China Flood Yellow River 2 900–2000 China Flood Yangtze-Huai 1 China 1000–4000 River Floods
Year 1219 1287 1911 1971 1530 1935 1975 1938 1887 1931
10. The St. Marcellus Flood of 1219, which occurred on January 16, 1219 (the feast day of St. Marcellus), 1219, was an immense storm tide of the North Sea that swept far inland from England and the Netherlands to Denmark and the German coast, breaking up islands, making parts of the mainland into islands, and wiping out St. Marcellus Flood – 1219 entire towns and districts. This storm tide, along with others of like size in the 13th and 14th centuries, played a part in the formation of the Zuiderzee, 177
and was characteristic of the unsettled and changeable weather in northern Europe during that era. 9. The St. Lucia’s Flood of 1287 affected the Netherlands and Northern Germany on December 14, 1287, the day after St. Lucia Day, killing approximately 50,000– 80,000 people in one of the largest floods in recorded history. The same storm also killed people in England. A violent weather pattern known as a “Great Storm”— a high spring tide mixing with a low-pressure system and a European wind storm—caused an enormous storm surge that destroyed a major dike. The name ZuiderSt. Lucia’s Flood – 1287 zee dates from after this event, as the water in that area had previously been a freshwater lake that was directly connected to the North Sea only by the former river Vlie. The St. Lucia’s flood removed the last of a series of natural sandy dunes and boulder clay barriers after which the new, now salty, Zuiderzee came into existence and grew rapidly. 8. The Yangtze River Flood of 1911 was a calamitous event that inundated several provinces in central and eastern China as a result of the overflowing of a number of significant waterways, most notably the Yangtze and the Huai rivers. The immediate cause of the flooding was torrential rain, which led Yangtze River Flood – 1911 to river dikes and banks being breached. The downpours continued for months, and approximately 30,000 square miles of land was sub178
merged. An estimated 100,000 people died. Millions of acres of crops were destroyed, causing widespread famine that lasted well into the following year. 7. The Red River Delta Flood of 1971 was a severe flood in North Vietnam that occurred during the Vietnam War. Heavy monsoon rains, coupled with the wartime preoccupation of the civilian population that normally maintained the water works, led to extensive flooding on August 1, 1971. The torrential rains simply overwhelmed the dike system around the heavily populated delta Red River Delta Flood – 1971 area, which is not far above sea level. As well as directly killing an estimated 100,000 people, the flood also wiped out valuable crops, causing further hardship, especially as it occurredduring wartime. In an attempt to garner international opposition to the US’s most recent strategic bombing campaign, Rolling Thunder, the North Vietnamese Government began a propaganda campaign using images of the flood to allege that the US had begun targeting the Red River dikes. Information from North Vietnam was neither plentiful nor accurate, so relatively few details about the disaster are available. What is known is that the Red River, which runs near the capital city of Hanoi, experienced a “250year flood,” so there is little doubt that the destruction was immense. 6. The St. Felix’s Flood of 1530 occurred on Saturday, November 5, 1530, the name day of St. Felix. Large parts of Flanders and Zeeland were washed away. Eighteen villages and the city of Reimerswaal were situated 179
in the area. Because the city was located higher than the rest of the region, it was left isolated as a small island. The land around it couldn’t be protected despite nuSt. Felix’s Flood – 1530 merous attempts to dam up the area. More floods continued to plague the few people remaining, and eventually the city was abandoned. Today, the sunken city of Reimerswaal is a shellfish fishery, providing rich breeding grounds for the mussels that are harvested there. All told, more than 100,000 people were killed by the St. Felix’s Flood. 5. The Yangtze River Flood of 1935 in China was the fifth-deadliest flood in recorded history, with a death toll of about 145,000. The flood brought malaria, tuberculosis, and other diseases throughout the river valley. Millions more who survivedwere displaced, injured, sufYangtze River Flood – 1935 fered from loss of property or jobs, or malnutrition. 4. The Banqiao Dam Failure of 1975, a flash flood, occurred at a dam on the River Ru in Zhumadian City, Henan province, China, at 1:00 AM local time, on August 8, 1975. The failure of the dam, which was reported as being caused by excessive rainfall and damage from Typhoon Nina, resulted in 231,000 fatalities, more than any other dam failure in history—86,000 died in the initial flood, and 145,000 succumbed to subsequent disease and famine. In addition, about 5,960,000 buildings collapsed, and 11 million residents were affected. 180
While there were numerous engineering and construction shortcomings in the building of the dam, officially its failure was categorized as a natural, rather than a man-made, disaster, with government sources placing an emphasis on the Banqiao Dam Failure – 1975 weather. The People’s Daily maintained that the dam was designed to survive a “1,000-year flood” (12 inches of rainfall per day) but claimed that what occurred was a “2,000-year flood.” More than a year’s worth (31.5 inches) of rain fell within 24 hours, and new records were set with 7.46 inches of rainfall per hour and 41.73 inches per day, which weather forecasts failed to predict. During the event, 62 dams failed catastrophically or were intentionally destroyed. The resulting flood waters caused a wave 6.2 miles wide and 9.8–23 feet high, which rushed onto the plains below at nearly 31 miles per hour, almost wiping out an area 34 miles long and 9.3 miles wide, and creating temporary lakes as large as 4,600 square miles. Nine days later, over a million people were still trapped by the waters; they were unreachable by disaster relief workers and had to rely on airdrops of food. 3. The Yellow River Flood of 1938, sometimes spoken of as “the largest act of environmental warfare in history,” occurred when, in June of 1938, during the Second Sino-Japanese war, Chinese Nationalist troops intentionally destroyed several dikes on the Yellow River in an attempt to halt the rapid advance of Japanese forces into western and southern China. The floods covered and destroyed some 21,000 square miles of farmland and shifted the mouth of the Yellow River hundreds of miles 181
to the south. Thousands of villages were inundated or destroyed, and several million villagers were displaced from their homes. An estimated 500,000–800,000 died from drowning, disease, and famine. The Nationalist government, after initially claiming that the breach was caused by Japanese bombing, used the heavy casualties to demonstrate the scale of sacrifice required of the Chinese people. It claimed that 12 million people had been affected by the flood, and placed the number of deaths at 800,000. The flooded areas were affected for years to come. The flooded countryside had been Yellow River Flood – 1938 more or less abandoned and all the crops destroyed. Upon the recession of the waters, a large portion of the ground was uncultivable, as much of the soil was covered in silt. The irrigation channels were also ruined, further adding to the toll on the farmlands. Many of the public structures and housing were also destroyed, and those who survived were left destitute. 2. The Yellow River Flood of 1887 was the worst flood in the history of China (and the world) up to that time. Heavy rains throughout the summer led to the unexpected collapse of the dikes on September 28, 1887, and 50,000 square miles of land were inundated. The ground, already saturated, could absorb none of the water and, within an hour, a lake as big as Lake Ontario had formed on the adjacent plain, while a fierce wind completed the devastation. Eleven large towns and hundreds of villages were destroyed, while millions were left homeless. An estimated 900,000 to 2,000,000 died in the flooding and 182
subsequent epidemics and famine. Some of the peasants were able to reach terraces that were slightly higher than the Yellow River Flood – 1887 water level and waited there for someone to reach them. People from the city attempted to save as many of the survivors as they could by rowing around in small boats, but it was several days before effective rescue and repair could begin. Efforts by individuals and government agencies continued unabated all through the winter months. When the waters finally receded, the land was covered with a layer of muddy silt about 8 feet deep. 1. The Yangtze-Huai Floods of 1931 were the deadliest ever in Chinese and world history. The estimates of the number of people killed by the flood (and ensuing diseases and famine) range from 1,000,000 to 4,000,000. More than 70,000 square miles of land were inundated and 80 million people were left homeless. From 1928 to 1930, China was afflicted by a long drought. The subsequent winter of 1930–1931 was particularly harsh, creating large deposits of snow and ice in mountainous areas. Early in 1931, melting snow and ice flowed downstream and arrived in the middle Yangtze during a period of heavy spring rain. Ordinarily, the region experienced Yangtze-Huai Floods – 1931 three periods of high water during the spring, summer, and autumn, but in 1931, there was a single continuous deluge. The summer 183
was also characterized by extreme cyclonic activity—in July alone of that year, seven cyclones hit the Yangtze basin, which normally got only two a year. Rainfall for the month totaled over 24 inches, and these storms dumped the equivalent of one and a half times the average annual volume of precipitation in a single month. The water flowing through the Yangtze reached its highest level since record-keeping began in the mid-19th century. By August, the Yangtze, Yellow, and Huai Rivers had all burst through their badly constructed and badly maintained dikes, flooding an area larger than the size of England. Thousands died from drowning during the initial phase of the flood, but even more followed due to widespread famine and outbreaks of diseases such as cholera, typhoid fever, and dysentery. Disease was by far the biggest killer, accounting for 70% of all fatalities. In many areas, inundation continued well into the autumn, meaning that it was not possible to plant a secondary insurance crop in the winter. Although in most areas, floodwater had receded by the winter, the problems of waterlogging, infrastructure damage, and refugee displacement continued well into the next spring. Flood-related famine and epidemic diseases lasted until at least the summer of 1932, while those infected with endemic diseases continued to suffer the effects of the flood years after the disaster had abated. While the dikes were rebuilt, they were again poorly constructed, and similar severe flooding in the region returned in 1935.
Not only can floods be incredibly deadly, they can also be incredibly costly—right up there with earthquakes and hurricanes. Between 1900 and 2015, numerous 184
disastrous floods seriously impacted local economies around the world. Most of these have occurred in southern and central regions of Asia—specifically in the populous nations China, Thailand, Korea, and India. On the list of the 10-costliest floods during this period, only two countries outside of Asia appear—Germany and the United States, with two floods each. Here’s the list: Costliest Riverine Floods in World History Rank
Country
Date
10 9 8 7 6 5 4 3 2 1
United States Germany Germany India United States China North Korea China China Thailand
June 9, 2008 May 28, 2013 August 11, 2002 September, 2014 June 24, 1993 June 30, 1996 August 1, 1995 May 29, 2010 July 1, 1998 August 5, 2011
Damages (2018 BUS$) 11.7 14.0 16.3 17.0 20.0 20.3 24.8 20.8 46.4 49.8
The greatest financial damage ever caused by a riverine flood was from the one that inundated Thailand in July/August of 2011, after being triggered by a tropical storm. Of the country’s 77 provinces, 65 were declared to be flood disaster zones. The torrential rains and flooding persisted until January of the following year in some of the more extreme areas, and even the capital city of Bangkok was left with severe damage. With financial damages of $49.8 billion (2018 USD), this flood was the fourth-costliest natural disaster of any kind ever recorded in the world. Only three others
185
surpass it—the 2011 Tohoku earthquake in Japan, the 1995 Kobe earthquake in Japan, and Hurricane Katrina in the United States in 2005. The second and third most-devastating floods on the list both occurred in China, hitting the country very hard both in terms of destroying infrastructure and straining financial resources. The flood that occurred on July 1, 1998, cost $46.4 billion (2018USD), and China’s second-worst flood, on May 29, 2010, cost $20.8 billion (2018 USD). The third Chinese flood on the list, which happened on June 30, 1996, carried with it a cost of $20.3 billion (2018 USD). These three floods combined caused financial damages totaling more than $67 billion (2018 USD), making China one of the world’s countries most severely affected by natural disasters in modern times.
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Chapter 17
The Worst Riverine Floods in US History Riverine flooding disasters have claimed thousands of lives in the United States and, with our ethnocentric perspective, we are likely to think that some of them qualify as being among the world’s deadliest, but this is not the case. No flood in American history even ranks among the world’s top 50 in terms of fatalities. The reasons for this have to do with the United States being a highly developed, wealthy nation. This country does not have millions of impoverished peasants living crowded together in vulnerable flood plains. Moreover, it has a well-developed flood-warning system and reasonably effective evacuation plans. The United States’ 10-deadliest riverine floods in history are listed in the table below, and a brief discussion of each follows.
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Deadliest Riverine Floods in US History Rank Flood Name Location Year Fatalities 10 Buffalo Creek West Virginia 1972 125 9 Mill River Dam Massachusetts 1874 139 8 Big Thompson Colorado 1976 144 Canyon 7 Black Hills South Dakota 1972 238 6 Great Mississippi Mississippi 1927 246 River Basin 5 Brazos River Texas 1899 284 4 Ohio River Ohio River 1937 385 Basin 3 St. Francis Dam California 1928 431 2 Ohio Statewide Ohio 1913 467 1 Johnstown Pennsylvania 1889 2,209
10. The Buffalo Creek Flood of 1972, a flash flood, occurred on February 26, 1972, when a coal waste dam in West Virginia—constructed to hold water, coal waste, and silt—collapsed, releasing 132 million gallons of black waste water into the narrow Buffalo Creek Hollow. The onslaught created a wall of water 30 feet high that wiped out 17 communities downstream. Out of a population of 5,000 people, 125 were killed and 1,121 were injured. Over 4,000 were left homeless, and 507 houses were destroyed in addition to 44 mobile homes and 30 businesses. Some towns were rebuilt but others vanished forever. State and federal invesBuffalo Creek Flood Damage – tigations determined 1972 that the dam, which was owned and operated by the Buffalo Mining Company, was not built properly and that the mining company’s 188
parent, The Pittston Company, had disregarded the safety of the residents. 9. The Mill River Dam Failure of 1874, a flash flood, occurred on May 16 in western Massachusetts following a heavy rainfall. When the poorly constructed earthen dam suddenly gave way, a large section of the east bank of the Mill River collapsed and was carried downstream. The dam’s gatekeeper mounted a horse and galloped down the valley to warn the residents of Williamsburg of what was to come. Some residents fled to higher ground; others refused Mill River Dam Failure to believe the awful Destruction – 1874 news; and many never heard the warning. A 20-foot tall wall of water swept away everything in its path, and 139 people were killed. 8. The Big Thompson Canyon Flood of 1976, a flash flood, occurred on July 31, during a centennial celebration marking Colorado’s becoming a state. While partygoers were gathered in the canyon, a light rain began to fall in the late afternoon. It turned into a heavy rain in the early evening and, in a 2-hour span, a year’s worth of rain fell in the region. Water began to cascade down the mountainsides and, at 10:30 PM, a massive wave of water 20 feet high roared through the canyon at a speed of 20 miles per hour, washing over everything ahead Big Thompson Canyon Flood – 1976
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of it. There were 144 fatalities in the flood, and it resulted in about $150 million (2018 USD) of damages. 7. The Black Hills Flood of 1972, a flash flood, was the result of heavy thunderstorms striking the Rapid City region of South Dakota with 15 inches of rain on June 9. Flood waters from various creeks emptied into Rapid Creek, swelling that body of water to more than 300 times its regular volume. In a 2-hour span, the creek’s water level rose by 12 feet. Severe flooding of residential and commercial properties in Rapid City occurred when Canyon Lake Dam became clogged with debris and failed in the Black Hills Flood Damage – 1972 late evening hours. The flood caused 238 deaths and 3,057 injuries. Over 1,335 homes and 5,000 automobiles were destroyed, and the total cost of damages was estimated to be $965 million (2018 USD) 6. The Great Mississippi Flood of 1927 was the most destructive river flood in the history of the United States, covering 27,000 square miles where nearly a million people lived, reaching a depth of up to 30 feet. In the spring of 1927, following months of unrelenting rain, the lower Mississippi River swelled to its breaking point and overran its levee system. The resulting flood swamped some 16 million acres across seven states from Cairo, Illinois, to New Orleans. The damage was at its worst in Arkansas, Mississippi, and Louisiana, where the river inundated so much land it temporarily created a shallow lake over 75 miles wide and forced thousands to be evacuated by boat. A break near Greenville, Mississippi, was 190
the single greatest levee crevasse to ever occur along the Mississippi River. It single handedly flooded an area 50 miles wide and 100 miles long with up to 20 Great Mississippi Flood – 1927 feet of water. In Vicksburg, Mississippi, the river swelled to 80 miles wide. The flood finally subsided in August after having caused 246 fatalities. Hundreds of thousands of people had been made homeless; properties, livestock, and crops were destroyed. Damages have been estimated at $2.89 billion (2018 USD). 5. The Brazos River Flood of 1899 was initiated by heavy rainfall for 11 straight days, beginning on June 17, in the region of Freeport, Texas. Rainfall totals reached almost 9 inches that week across an area of 66,000 square miles. The Brazos River overflowed its banks and flooded the surrounding Brazos River Flood – 1899 area for 12,000 square miles. In July, flood waters rose over 58 feet in the town of Richmond. As a result of the flood, 284 lives were lost, and an estimated $273 million (2018 USD) in damages were caused. 4. The Ohio River Flood of 1937 took place in late January and February, with damage extending from Pittsburgh to Cairo, Illinois, The flood was exacerbated by record rainfall in river cities such as Louisville, Kentucky (20 inches), Evansville, Indiana (15 inches), and Cincinnati, Ohio (14 inches). As the water rose, gas 191
tanks exploded and oil fires ignited along the river. On January 26, the river gauge in Cincinnati reached 80 feet, the highest level in the city’s history. While 20% of the City of Cincinnati itself was under water, much of the area outside of that which was flooded was largely paralyzed due to lack of fresh water, electricity, and heat. On January 27, the river gauge in the Louisville area reached 57 feet, setting Ohio River Flood – 1937 a new record and resulting in 70% percent of the city being under water at that time. The number of people who perished in the flood was 385. One million were left homeless, and damages reached $8.7 billion (2018 USD). The extent of the damage throughout the Ohio and Mississippi river valleys was so great that the American Red Cross claimed the deluge shattered all previous records for natural disasters in the United States. 3. The St. Francis Dam Failure of 1928, a flash flood, in the San Francisquito Canyon of the Sierra Pelona Mountains, about 40 miles northwest of downtown Los Angeles, was among the greatest dam catastrophes in US history. Built in 1926, the 1,300-foot dam held more than 12 billion gallons of water, enough to supply Los Angeles for a year. But there were integrity issues having to do with the dam from the beginning. Near the end of February, a notable leak of 4.5 gallons per second began at the base of the wing dike approximately 150 feet west of the main dam. During the first week of March, the leak had approximately doubled in volume. On March 7, 1928, the reservoir was 3 inches below the spillway crest, and 192
the chief engineer ordered that no more water be directed into the reservoir. On the morning of March 12, while conducting his usual inspection of the dam, the dam keeper discovered a new leak in the west abutment. The leak was discharging approximately 2 gallons of water per second. At 11:57 PM on March 12, 1928, the dam failed catastrophically, unleashing a flood wave that was initially 140 feet high. The dam keeper and his family were most likely among the first casualties caught in the flood wave, which swept over their cottage approximately a quarter of a mile downstream from the dam. Neither his body nor that of his six-year-old son were ever found. There were no surviving eyewitnesses to the collapse, but at least five people passed the dam within the hour prior to its failure and did not notice anything unusual. Five minutes after the collapse, at about 12:02 AM on March 13, the then–120-foot-high flood wave had traveled 1 ½ miles at an average speed of 18 miles per hour, destroying everything in its path. As the floodwater entered the Santa Clara riverbed at about 12:40 AM, it overflowed the river’s banks, flooding parts of presentday Valencia and Newhall. The mass of water—then 55 feet high and traveling at 12 miles per hour—followed the river bed west and heavily damaged the towns of Fillmore, Bardsdale, and Santa Paula, before emptying both victims and debris into the Pacific Ocean, 54 miles downstream just south of Ventura, at around 5:30 AM. At that point, the wave was almost 2 miles wide and still traveling at 6 miles per hour. Bodies were recovered as far south as the Mexican border; many were never found. Ruins of St. Francis Dam – 1928 193
It was later found that the main dam had broken into several large pieces and numerous smaller pieces, all of which were washed downstream as the 12.4 billion gallons of water began surging down San Francisquito Canyon. The largest piece, weighing approximately 10,000 tons was found about three-quarters of a mile below the dam site. Among the various commissions formed to investigate the disaster, the consensus was that the failure occurred because the dam’s foundation had been built on unstable soil. It is now believed that the event had begun with the eastern abutment of the dam giving way, possibly due to a landslide. Because many bodies were presumably never found, the final death toll could never be determined with certainty, but it is currently estimated to have been at least 431. Damages have been estimated at $291.8 million (2018 USD). 2. The Ohio Statewide Flood of 1913 was the result of the worst weather event in Ohio history, which occurred between March 23rd and 26th, with excessive rainfall throughout the entire state. By March 25, the Ohio River and its tributaries flooded cities such as Indianapolis, Indiana, and Cincinnati, Youngstown, and Columbus, Ohio. Dayton, Ohio, was particularly hard-hit as swiftly flowing water up to 10 feet deep swept through downtown streets, killing 123 people. Downstream in nearby Hamilton, Ohio, about 100 people died Ohio Statewide Flood – 1913 after water 10 to 18 feet deep flowed into its residential neighborhoods. At Cincinnati, the Ohio River rose 21 feet in 24 hours. The storms that created these floods were part 194
of a much more extensive storm system, which was collectively called the “Great Flood of 1913;” it caused flooding in more than a dozen states in the Midwest and the Northeast. The same weather system caused major tornadoes in the Great Plains, the South, and the Midwest. The exact death toll from this flood and its aftermath may never be known, but for the state of Ohio, it has officially been placed at 467; damages have been estimated at $3.25 billion (2018 USD). 1. The Johnstown Flood of 1889, a flash flood, occurred on May 31 following the catastrophic failure of the privately owned and poorly maintained South Fork Dam on the Little Conemaugh River 14 miles upstream from the town of Johnstown, Pennsylvania. After several days of extremely heavy rainfall, the dam broke and released 20 million tons of water into the narrow valley below. To the east, this event also caused a major flood for the Susquehanna River and its tributaries. Damage was not limited to Pennsylvania, however. The flood eclipsed all previous records for water levels on the Potomac River. Between 2:50 and 2:55 PM, the South Fork Dam breached, and it took approximately 65 minutes for most of the 3.8-billion-gallon lake to empty after the dam began to fail. The 420,000-cubic-feet-per-second flow rate of the water temporarily equaled the average flow rate of the Mississippi River at its delta. Continuing on its way downstream to Johnstown, 14 miles west, the water picked up debris, such as trees, houses, and animals. At the Conemaugh Viaduct, a 78-foot-high railroad bridge, the flood was momentarily stemmed when this debris jammed against the stone bridge’s arch. But within 7 minutes, the viaduct collapsed, allowing the flood to resume its course. Owing to the delay at the stone arch, however, the flood waters gained renewed hydraulic 195
head, resulting in a stronger, more abrupt wave of water hitting places downstream more heavily than otherwise would have been expected. Some 57 minutes after the South Fork Dam collapsed, the flood hit Johnstown. The residents were caught by surprise as the 40-foot-high flood wave traveling at 40 miles per hour bore down on them. It demolished some 1,600 buildings and swept away everything in its path. Four square miles of downtown Johnstown were completely destroyed. The flood was responsible for 2,209 fatalities (in- Johnstown Flood Destruction – cluding 99 entire fami1889 lies); bodies were found as far away as Cincinnati. Damages amounted to approximately $453 million (2018 USD). It was the first major disaster in which the American Red Cross was involved.
While the foremost deadliest floods of the United States occurred about a century ago, many of its costliest floods have been much more recent. As Americans have become wealthier—and urban planners have become more audacious—more expensive residences and commercial buildings have been built in the high-risk zones for dangerous floods, which accounts for flood costs growing with time. Below is a list of the 10 costliest riverine floods to occur in the US.
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Costliest Riverine Floods in US History Rank Flood Name Location Year Damages (2018 BUS$) 10 Ohio Statewide Ohio 1913 3.25 9 Christmas Pacific 1964 3.07 Northwest 8 Willamette ValPacific 1996 3.47 ley Northwest 7 South Platte Colorado 1965 3.94 6 North CaliforCalifornia 1995 4.29 nia 5 Great Northeast New England 1936 4.72 4 Great Kansas Kansas, Mis- 1951 6.71 souri 3 Louisiana Louisiana 1995 7.87 2 Ohio River Ohio River 1937 8.7 Basin 1 Great MissisMississippi 1993 30.2 sippi River Basin
The Ohio Statewide Flood of 1913, in addition to being the 10th costliest flood in US history—with damages of $3.25 billion (2018 USD)—was also the second-deadliest, with 467 fatalities. It was the result of the worst weather event in Ohio history, which caused excessive rainfall throughout the entire state. The Ohio River Flood of 1937, which was exacerbated by record rainfalls throughout the area, caused damages extending from Pittsburgh to Cairo, Illinois. In addition to being the second-costliest flood, with damages of $8.7 billion (2018 USD), it was the fourth-deadliest, with a death toll of 385. The Great Mississippi Flood of 1993 was caused by excessive rainfall in the Mississippi River basin over a period of several months. It was the most destructive 197
flood in the history of the United States, affecting almost the entire Midwest across 20 million acres. The flood took 32 lives and caused damages of $30.2 billion (2018 USD).
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Chapter 18
Hurricane- and TsunamiRelated Floods Hurricane- and tsunami-related floods, as mentioned previously, have been treated separately from riverine floods, because a major portion of their fatalities and damages are the result of event-related factors other than flooding, and the distinction is often impossible to make. The foremost factor influencing the destructiveness of hurricane-related floods is storm surge, a coastal flood phenomenon of water rising beyond what would be expected as a result of the normal movement related to tides, which is commonly associated with low-pressure weather systems. The severity of a storm surge is affected by the shallowness and orientation of the water body relative to the storm path as well as the timing of tides. Most casualties during hurricanes occur as the result of storm surges. The two main meteorological factors contributing to a storm surge are a long fetch of winds spiraling inward toward the storm, and a low-pressure-induced dome of water drawn up under and behind the storm’s center. This low-pressure-induced effect is estimated to cause a 0.39-inch increase in sea level for every millibar drop in 199
atmospheric pressure. There are other operative elements at work as well. • Strong surface winds cause surface currents (an effect called the “wind set-up”), which cause water levels to increase at a downwind shore and to decrease at an upwind shore, with the effect being proportional to depth. The pressure effect and the wind set-up on an open coast will cause water to be driven into bays in the same way as the astronomical tide.
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•
The effect of waves, when directly powered by the wind, is distinct from a storm’s wind-powered currents. Powerful wind causes large strong waves that move in the direction the wind is blowing. Although these surface waves are responsible for very little water transport in open water, they may be responsible for significant transport near the shore. When waves are breaking on a line more or less parallel to the beach, they carry considerable water shoreward. As they break, the water moving toward the shore has considerable momentum and may run up a sloping beach to an elevation above the mean water line, which may exceed twice the wave height before breaking.
•
The Earth’s rotation causes the Coriolis effect, which bends currents to the right in the Northern Hemisphere and to the left in the Southern Hemisphere. When this bend brings the currents into more perpendicular contact with the shore, it can amplify the surge; and when it bends the current away from the shore, it has the effect of lessening the surge.
•
The rainfall effect is experienced predominantly in estuaries. Hurricanes may dump enormous
quantities of rain over large areas in short periods of time, and the resulting surface run-off can quickly flood streams and rivers. This can increase the water level near the head of tidal estuaries as storm-driven waters surging in from the ocean meet rainfall flowing downstream into the estuary. Below, presented in chronological order, is a list of hurricanes since 1900 that have caused significant flooding in the United States.
Year
1900
Hurricane-Related Flooding in US Storm Name Location Fatalities
1969
Great Galveston Great Miami Okeechobee Labor Day Great New England Camille
1992
Andrew
2005 2012
Katrina Sandy
2017
Harvey
1926 1928 1935 1938
Texas
8,000
Damages (2018 BUS$) 0.63
South Florida South Florida Florida Keys New England, Long Island Gulf Coast, Midwest Florida, Louisiana Gulf Coast New Jersey, New York Texas
372 4,075 485 682
1.21 1.47 0.11 5.51
259
9.77
65
47.7
1836 233
139.6 83.5
107
128.7
The 1900 Great Galveston Hurricane, a category-4 storm with winds of up to 145 miles per hour, made landfall on September 8, 1900, in Galveston, Texas. Its lowest recorded barometric pressure was considered 201
at the time to be so low, it was believed to be an error. Due to contradictory weather forecasts, the people of Galveston felt no alarm; not many residents heeded the Weather Bureau’s warnings, and few evacuated across Galveston’s bridges to the mainland. On the morning of Saturday, September 8, a 15-foot storm surge washed over the long, flat island-city, which was only 8 feet above sea level, knocking buildings off their foundations and destroying over 3,600 homes. By early afternoon, the wind had picked up, and by 5 PM, sustained hurricaneforce winds were being recorded. On Sunday morning, clear skies and a 20-mile-per-hour breeze off the Gulf of Mexico greeted the Galveston survivors. As severe as the damage to Galveston’s buildings was, the human toll was even greater. Because of the destruction of the bridges to the mainland and the telegraph lines, no word of the city’s destruction could reach the mainland. When messengers were finally able to get to the telegraph office in Houston at 3 AM on September 10, a short message was sent to the Texas Governor and the US President advising that the city of Galveston was in ruins. When rescuers eventually arrived, they found the city completely destroyed, and almost 20% of the island’s population dead. Most had drowned or been crushed as the waves pounded the debris that had been their homes hours earlier. Many sur1900 Great Galveston vived the storm itself but Hurricane Flooding died after several days 202
of being trapped under the wreckage of the city, with rescuers unable to reach them. The dead bodies were so numerous that burying all of them was impossible. The dead were initially weighted down on barges and dumped at sea, but when the gulf currents washed many of the bodies back onto the beach, it became necessary to set up funeral pyres on the beaches, or wherever dead bodies were found, and they burned day and night for several weeks after the storm. More people in the US were killed in this single storm than the total of those killed in all the tropical cyclones that have struck the country since. The death toll was 8,000 people, and the damages have been estimated at $630 million (2018 USD). The 1926 Great Miami Hurricane was a Category 4 storm with winds of 150 miles per hour that struck Miami, Florida, on September 18, devastating the area and causing extensive damage in the Bahamas and the. US Gulf Coast. When the storm made landfall just south of downtown Miami, it was very large in size, with a radius of 375 miles; and hurricane-force winds 1926 Great Miami were reported from the Hurricane Flooding upper Florida Keys to near St. Lucie County. The accompanying high storm surge swept into Miami and Miami Beach, flooding city streets with knee-deep water. Yachts and other large vessels were carried by the intense wind and waves onto shore. While most wooden buildings in Miami were either blown down or lost their roofs, concrete and steel buildings were warped at their bases. 203
A storm surge from Lake Okeechobee entirely inundated Clewiston, reportedly leaving numerous bodies along the road connecting the city with Miami. Further inland, the surge burst through frail, earthen, 6-foot-tall muck dikes, submerging Moore Haven under 13–15 feet of water. Residents scrambled, often unsuccessfully, to seek safety on rooftops, but they were swept away by the winds and storm surge; most of the city’s buildings were swept off their original foundations. As many as 150 human corpses were found in Moore Haven alone, but the estimates were incomplete as many bodies were never found, reportedly having been carried deep into the Everglades. The hurricane quickly traversed the Florida peninsula before emerging in the Gulf of Mexico, where it reached a secondary peak intensity with winds of 125 mph on September 20. It flooded surrounding communities and barrier islands, while strong winds downed trees and disrupted electrical service. The storm later made two landfalls with weaker intensities in Alabama and Mississippi on September 20 and 21, respectively, causing additional but less severe damage in those states, primarily from heavy rains and storm surge. Land interaction caused the cyclone to weaken and later dissipate on September 22. Pensacola, Florida, encountered sustained winds of hurricane force for more than 20 hours, including winds above 100 miles per hour for 5 hours. The storm tide destroyed nearly all waterfront structures on Pensacola Bay and peaked at 14 feet near Bagdad, Florida. The maximum rainfall occurred at Bay Minette, Alabama, where 18.5 inches fell. The storm caused 372 fatalities and 6,000 injuries, as well as leaving about 43,000 people homeless. Property damage was the highest in US history up to that time; 204
it is estimated to have been approximately $1.21 billion (2018 USD). The 1928 Okeechobee Hurricane made landfall early on September 17 near West Palm Beach, Florida, with winds of 145 miles per hour. In that city, more than 1,711 homes were destroyed, and 6,369 others were damaged. Likewise, there was also severe wind damage in Palm Beach. Inland, the hurricane wreaked widespread destruction along the heavily populated coast of Lake Okeechobee. Numerous houses and buildings were swept away in the cities of Belle Glade, Canal Point, Chosen, Pahokee, and South Bay. Residents had been warned to evacuate the low ground earlier in the day, but after the hurricane did not arrive on schedule, many thought it had missed and they returned to their homes. When the worst of the storm crossed the lake, the south-blowing wind caused a storm surge to overflow the small dike that had been built at the 1928 Okeechobee lake’s south end. The Hurricane Flooding resulting flood covered an area of hundreds of square miles with water that in some places was over 20 feet deep. Houses were floated off their foundations and dashed to pieces against any obstacle they encountered. Most survivors and bodies were washed out into the Everglades, and quite a few of the bodies were never found. As the rear eyewall of the storm passed over the area, the flood reversed itself, breaking the dikes along the lake’s northern shore and causing similar but lesser flooding. 205
While crossing Florida, the system weakened significantly, falling to Category 1 intensity late on September 17. It curved north-northeastward and briefly re-emerged in the Atlantic on September 18, then soon made another landfall near Edisto Island, South Carolina, with winds of 85 miles per hour. Early on the following day, the system weakened to a tropical storm and became extratropical over North Carolina hours later. Floodwaters in Florida persisted for several weeks, greatly impeding attempts to clean up the devastation. Burial services were quickly overwhelmed, and many of the bodies were buried in mass graves. The final death toll of 4,075 made the Okeechobee hurricane the seconddeadliest natural disaster in United States history behind the 1900 Galveston hurricane. Total damages from the hurricane amounted to $1.47 billion (2018 USD). The 1935 Labor Day Hurricane was, at the time, the most intense hurricane to make landfall in the United States. It was a Category 5 storm that carried winds of 185 miles per hour and caused extreme damage in the upper Florida Keys, as a storm surge of approximately 18–20 feet swept over the low-lying islands. The hurricane’s strong winds and the surge destroyed nearly all the structures between Tavernier and Marathon. The town of Islamorada was obliterated. Portions of the Key West Extension of the Florida East Coast Railway were severely damaged or destroyed. Three veterans’ work camps, with a total of 695 veterans on their payrolls, existed in the Florida Keys before the hurricane. A special train was sent to evacuate those camps, but on Upper Matecumbe Key, near Islamorada, the 11-car evacuation train encountered a powerful storm surge topped by cresting waves. All 11 cars were swept from the tracks, but, remarkably, everyone on the train survived. Only the locomotive and 206
tender remained on the rails, and they were barged back to Miami several months later. Three ships ran afoul of the storm. Just offshore of Upper Matecumbe Key, the Danish motorship Leise Maersk—after being totally disabled by the wind and sea, and with its engine room flooded—was carried over Alligator Reef and grounded nearly 4 miles beyond. No one died and the ship was salvaged on September 20. The American tanker Pueblo, having gone out of control, drifted helplessly in the storm 1935 Labor Day Hurricane Flooding from 2 PM to 10 PM on September 2. It was carried completely around the storm center, finding itself 8 hours later about 25 miles northeastward of its original position, and was just barely able to claw off Molasses Reef. The ship that made the headlines, however, was the American steamship Dixie out of New Orleans, with a crew of 121 and 229 passengers. It ran aground on French Reef, near Key Largo, fortunately without loss of life. It was re-floated on September 19 and towed to New York. The hurricane left a path of nearly total destruction in the Upper Keys, centered on what is today the village of Islamorada. The links—rail, road, and ferry boats— that chained the islands together were broken. Craig Key, Long Key, Upper Matecumbe Key, and Lower Matecumbe Keys suffered the worst. After the third day of the storm, bodies were scattered throughout the Keys and their rapid decomposition created ghastly conditions. Public health officials ordered a ban on all movement of 207
bodies, requiring their immediate burial or cremation in place. The hurricane also caused additional wind and flood damage in northwest Florida, Georgia, and the Carolinas. After leaving the Keys, it skirted the Florida Gulf Coast on a broad recurve, passed inland at Cedar Key, and finally left the continent near Cape Henry, Virginia. Eventually, the death toll was reported to be 485, of which 257 were veterans. Total damage costs for the hurricane were initially estimated at $6 million (1935 USD), which equates to $110 million 2018 USD, but all indications are that this was a gross understatement. The 1938 Great New England Hurricane was one of the deadliest and most destructive tropical cyclones to strike Long Island, New York, and New England. On September 20, the storm is estimated to have reached Category 5 hurricane intensity while centered east of the Bahamas. It made landfall on Long Island on September 21 as a Category 3 hurricane. The storm’s forward speed was an extraordinary 50 miles per hour, and it moved in the same general direction as the winds on the eastern side of the storm as it proceeded north; this, in turn, caused the wind speed to be far higher in areas east of the storm’s eye than would be the case with a hurricane of more typical forward speed. Moreover, this rapid movement did not permit enough time for the storm to weaken over the cooler waters before it reached Long Island. As the storm moved northward, its western edge caused moderate damage in New Jersey, New York City, and western Long Island. It made landfall at Bellport in Long Island’s Suffolk County sometime between 2:10 and 2:40 PM as a Category 3 hurricane, with sustained winds of 120 miles per hour, gusts up to 150 miles per hour, and storm surge 25–35 feet high. 208
On eastern Long Island. The Dune Road area of Westhampton Beach was obliterated. The storm surge temporarily turned Montauk into an island as it flooded across the South Fork at Napeague and destroyed the tracks of the Long Island Rail Road. Ten new inlets were created on eastern Long Island. The surge rearranged 1938 Great New England the sand at the Cedar Hurricane Flooding Point Lighthouse so that the island became connected to what is now Cedar Point County Park. The surging water created the Shinnecock Inlet by carving out a large section of barrier island separating Shinnecock Bay from the Atlantic Ocean. The storm surge inundated Block Island and then hit Westerly Rhode Island with deadly storm tides of 18 to 25 feet. As the surge drove northward through Narragansett Bay, it was restricted by the Bay’s funnel shape and rose to 15.8 feet above normal spring tides, resulting in more than 13 feet of water in some areas of downtown Providence. The hurricane made a second landfall as a Category 3 storm somewhere between Bridgeport and New Haven, Connecticut, at around 4:00 PM, with sustained winds of 115 mph. Long Island acted as a buffer against large ocean surges, but the waters of Long Island Sound still rose to great heights. Small shoreline towns to the east of New Haven experienced much destruction from the water and winds, and the 1938 hurricane holds the record for the worst natural disaster in Connecticut’s 350-year history. The storm tide was 14.1 feet in Stamford, 12.8 feet in Bridgeport, and 10.58 feet in New London, which remains a record high. After being swept by the winds 209
and storm surge, New London’s waterfront business district caught fire and burned out of control for 10 hours. The eye of the storm followed the Connecticut River north into Massachusetts. In Springfield, the river rose 6 to 10 feet above flood stage, causing significant damage. Up to 6 inches of rain fell across western Massachusetts, which combined with over 4 inches that had fallen a few days earlier to produce widespread flooding. To the east, the surge left Falmouth and New Bedford under 8 feet of water. The Blue Hill Observatory registered sustained winds of 121 miles per hour and a peak gust of 186 miles per hour, which is the strongest hurricane-related surface wind gust ever recorded in the United States. A 50-foot wave, the tallest of the storm, was recorded at Gloucester. The storm entered Vermont as a Category 1 hurricane, with powerful winds causing extensive damage to trees, buildings, and power lines. The 1938 hurricane has been the only tropical cyclone ever to make a direct hit on Vermont in its recorded history. As the hurricane was transitioning into an extratropical cyclone, it tracked into southern Quebec and continued to produce heavy rain and very strong winds, but damage was generally minimal. The post-tropical remnants of the storm dissipated over northern Ontario a few days later. The hurricane was estimated to have killed 682 people, damaged or destroyed more than 57,000 homes, and caused property losses of $5.51 billion (2018 USD). The 1969 Hurricane Camille was one of three catastrophic Category 5 hurricanes to make landfall in the United States during the 20th century (the others being the 1935 Labor Day Hurricane and the 1992 Hurricane Andrew). It struck near the mouth of the Mississippi River on the night of August 17 with estimated sustained winds of 175 miles per hour and a peak official storm surge of 24 feet. The hurricane flattened nearly everything along the 210
coast of Mississippi, and caused additional flooding and deaths inland while crossing the Appalachian Mountains of Virginia. Electricity was lost during the storm’s approach to the Mississippi coastline, and US Highway 90 flooded as a large storm surge overtopped seawalls. Fires consumed several coastal communities, and along Mississippi’s entire shore, extending some three to four blocks inland, the destruction was nearly complete, with some 3,800 homes and businesses destroyed. Alabama also experienced damage along US Highway 90, and 26,000 homes and over 1,000 businesses were wiped 1969 Hurricane Camille Flooding out across the state. The storm’s large circulation also resulted in a 3- to 5-foot storm surge in Apalachicola, Florida. The hurricane weakened as it progressed inland, becoming a tropical storm and then a tropical depression as, on August 20, it turned eastward through Kentucky, dropping heavy rainfall in West Virginia and Virginia. A widespread area of western and central Virginia received over 8 inches of rain, leading to significant flooding across the state. The James and Tye rivers crested well above flood stage in many areas, including a record high of 41.3 feet at Columbia, Virginia. Camille was considered one of the worst natural disasters in central Virginia’s recorded history. In total, Hurricane Camille killed 259 people and caused $9.77 billion (2018 USD) in damages. The 1992 Hurricane Andrew was a Category 5 Atlantic hurricane that struck the Bahamas, Florida, and 211
Louisiana in late August with wind speeds up to 165 miles per hour. At the time of its occurrence, it was the most destructive hurricane in United States history. On August 24, Andrew made two separate landfalls in South Florida—the first on Elliott Key, and the second, 25 minutes later, in Homestead. The Miami-Dade County cities of Florida City, Homestead, and Cutler Ridge received the brunt of the storm. Rainfall in Florida was substantial, peaking at 13.98 inches in western Miami-Dade County. After striking Florida, Andrew moved across the Gulf of Mexico at Category 4 1992 Hurricane Andrew Flooding strength and, before moving ashore again, caused extensive damage to oil platforms. After weakening slightly, Andrew made landfall again near Morgan City in south-central Louisiana as a low-end Category 3 storm with maximum sustained winds of 115 miles per hour. The accompanying storm surge of at least 8 feet caused flooding along the coast, and river flooding was also reported. The effects of land caused the small hurricane to rapidly lose its intensity, and it diminished to a tropical depression by August 27 while crossing Mississippi. The next day, Andrew merged with a frontal system over the southern Appalachian Mountains. Throughout its path, Andrew left 65 dead and caused $47.7 billion (2018 USD) in damages. The 2005 Hurricane Katrina was the costliest natural disaster, as well as one of the five deadliest hurricanes, in the history of the United States. The storm is currently ranked as the third most intense United States tropical 212
cyclone to make landfall, behind only the 1935 Labor Day Hurricane and the 1969 Hurricane Camille. Katrina originated over the Bahamas on August 23, headed generally westward toward Florida, and strengthened into a hurricane only 2 hours before making its first landfall at Hallandale Beach and Aventura on August 25. The storm produced heavy rainfall in portions of the Miami metropolitan area, with a peak total of 16.43 inches, and caused local flooding in the Miami-Dade County area. Katrina crossed Florida and, after very briefly weakening to a tropical storm, emerged in the Gulf of Mexico on August 26. There it began to rapidly strengthen, becoming a Category 5 hurricane with 175 miles per hour winds over the warm waters of the Gulf. On August 28, it weakened again before making a second landfall in southeast Louisiana on August 29 as a Category 3 hurricane with sustained winds of 125 miles per hour. After moving over southeastern Louisiana and Breton Sound, the storm made its third landfall near the Louisiana/Mississippi border, still at Category 3 intensity, with 120 miles per hour sustained winds. It maintained its power well into Mississippi, finally losing hurricane strength more than 150 miles inland near Meridian, Mississippi. It was downgraded to a tropical depression near Clarksville, Tennessee, but its remnants were still discernible in the eastern Great Lakes region on August 31, when it was absorbed by a frontal boundary. As Katrina came ashore on the Gulf Coast, its accompanying storm surge reached a height of 27 feet in Mississippi, 12–14 feet in Louisiana, and 12–16 feet in Alabama; even in Pensacola, Florida, it was 5.37 feet. Katrina’s 27-foot storm surge in Mississippi was the most extensive, as well as the highest, in the documented history of the United States. It penetrated 6 miles inland in 213
many areas and up to 12 miles along some bays and rivers, with all coastal areas of the state suffering massive damage from the storm’s impact. The storm traveled up the entire state, and afterwards, all 82 counties in Mississippi were declared disaster areas for federal assistance. Battered by wind, rain, and storm surge, 2005 Hurricane Katrina Flooding some beachfront neighborhoods were completely leveled, and preliminary estimates indicated that 90% of the structures within half a mile of the coastline were completely destroyed. On US Highway 90 along the Mississippi Gulf Coast, two major bridges were completely destroyed—the Bay St. Louis– Pass Bridge and the Biloxi–Ocean Springs Bridge. Additionally, the eastbound span of the I-10 Bridge over the Pascagoula River estuary was damaged. While the storm surge in Mississippi was higher, a very significant surge affected the Louisiana coast. On August 29, as the eye of the storm swept to the northeast, Katrina’s storm surge caused 53 breaches of various flood-protection structures in and around the greater New Orleans area, submerging 80% of the city. The storm also brought heavy rain to Louisiana, with 8–10 inches falling on a wide swath in the eastern part of the state. The highest rainfall recorded in the state was approximately 15 inches. As a result of the rainfall and storm surge, the level of Lake Pontchartrain rose and caused significant flooding along its northeastern shore. As several bridges were destroyed and most of the major roads into and out of New Orleans were damaged, the only available routes were the westbound Crescent 214
City Connection and the Huey P. Long Bridge. Katrina displaced over one million people from the central Gulf Coast to elsewhere across the US, becoming the largest diaspora in the history of the United States. Katrina also had a profound impact on the environment. The storm surge caused major beach erosion, in some cases completely devastating coastal areas. The sand on Dauphin Island, a barrier island off the coast of Mississippi, was transported across the island into the Mississippi Sound, pushing the island towards land. The storm surge and waves from Katrina also severely damaged the Chandeleur Islands, which had been affected by the 2004 Hurricane Ivan. An estimated 217 square miles of land was transformed to water by Hurricane Katrina and the 2005 Hurricane Rita combined. The lands that were lost were breeding grounds for marine mammals, brown pelicans, turtles, fish, and migratory species such as redhead ducks. Katrina also produced massive tree loss along the Gulf Coast. Finally, as part of the cleanup effort, the flood waters that covered New Orleans were pumped into Lake Pontchartrain, a process that took 43 days to complete. These residual waters contained a mix of raw sewage, bacteria, heavy metals, pesticides, toxic chemicals, and oil, which sparked fears in the scientific community that massive numbers of fish would die. Approximately 1,836 people died in the hurricane and associated floods, making Katrina the deadliest United States hurricane since the 1928 Okeechobee Hurricane. Total property damage has been estimated at $139.6 billion (2018 USD), roughly four times the damage wrought by the 1992 Hurricane Andrew, the previously most costly hurricane. The 2012 Hurricane Sandy, at its peak intensity, was a Category 3 storm with winds of 115 miles per 215
hour when it made landfall in Cuba on October 25. It also caused damage and fatalities in Jamaica, Haiti, the Dominican Republic, Puerto Rico, and the Bahamas. While it was a Category 2 storm off the coast of the Northeastern United States, the storm became the largest Atlantic hurricane on record (as measured by diameter, with winds spanning 1,100 miles). Early on October 29, the storm curved west-northwest and moved ashore near Brigantine, New Jersey, just to the northeast of Atlantic City, with winds of 80 miles per hour, as a post-tropical cyclone with hurricane-force winds. In the United States, Hurricane Sandy affected 24 states, including the entire Eastern Seaboard from Florida to Maine, and west across the Appalachian Mountains to Michigan and Wisconsin. With 92-mile-per-hour wind speeds and a storm surge of approximately 14 feet, the storm caused particularly severe damage in New Jersey and New York. In New York, at least 53 people—43 of them in New York City—died as a result of the storm. Throughout the state, thousands of homes—100,000 of them on Long Island—and an estimated 250,000 vehicles were destroyed. The East River overflowed its banks, and seven subway tunnels under the East River were flooded, as were all road tunnels entering Manhattan except the Lincoln Tunnel. In New Jersey, storm surge and flooding affected a large swath of the state. There were 43 storm-related deaths, and 346,000 homes were damaged or destroyed. Both Jersey City and Hoboken suffered serious flooding, and portions of the cities had to be evacuated. The Jersey Shore experienced the most severe winds and surf from the storm and suffered the most damage in what was its second-highest flood in history. While moving ashore near Atlantic City, Sandy dropped heavy rainfall that reached 11.62 inches in Wild216
wood Crest. The seaside communities on Long Beach Island were also heavily damaged, with scores of homes and businesses destroyed and the storm surge depositing up to 4 feet of sand on island streets, 2012 Hurricane Sandy Flooding Damage making them impassable. On average, New Jersey beaches were 30 to 40 feet narrower after the hurricane. At least 233 people in eight countries were killed along the path of the storm. The total damages from Sandy are estimated to have been about $83.5 billion (2018 USD). The 2017 Hurricane Harvey that hit Texas on August 26–27, 2017, was the wettest tropical cyclone on record in the United States. The resulting floods inundated hundreds of thousands of homes, displaced more than 30,000 people, and prompted more than 17,000 rescues. Many locations in the Houston Metropolitan area observed at least 30 inches of precipitation, with a maximum of 60.58 inches in Nederland. Houston experienced all-time-record daily rainfall accumulations on both August 26 and 27, measured at 14.4 inches and 16.08 inches, respectively. Harvey became a major hurricane and attained Category 4 intensity with winds of 130 miles per hour on August 25. It made landfall at San José 2017 Hurricane Harvey Flooding Island, Texas, at peak 217
intensity, followed shortly thereafter by another landfall at Holiday Beach at Category 3 intensity. Afterwards, rapid weakening ensued, and Harvey was downgraded to a tropical storm as it stalled near the coastline, dropping torrential and unprecedented amounts of rainfall over Texas. On August 28, it emerged back over the Gulf of Mexico, strengthening slightly before making a final landfall with winds of 45 miles per hour in Louisiana on August 29. As Harvey drifted inland, it quickly weakened again as it became extratropical on September 1, before dissipating 2 days later. Harvey was responsible for 107 fatalities. An estimated 300,000 structures and 500,000 vehicles were damaged or destroyed in Texas alone, and damages have been estimated at $128.7 billion (2018 USD). The 2018 Hurricane Florence was among the wettest tropical cyclones to impact the United States. While crossing the Atlantic on September 10, it became a Category 4 hurricane with maximum sustained winds of 140 miles per hour. Increasing wind shear caused its intensity to taper off over the next few days, and, by the evening of September 13, it was downgraded to a Category 1 hurricane as it began to stall while nearing the Carolina coastline. On the morning of September 14, Florence made landfall just south of Wrightsville Beach, North Carolina, as a Category 1 hurricane, with sustained winds of 90 miles per hour. The hurricane began a weakening trend after making landfall, and its forward speed decreased, causing it to move very slowly west to southwestward as it produced torrential rainfall (with a maximum total of 35.93 inches in Elizabethtown) over the Carolinas. Late on September 14, Florence weakened to a tropical storm over extreme southeastern North Carolina, and continued weakening while dropping heavy rain; it weakened again into a 218
tropical depression on September 16, while located over South Carolina. On September 17, the storm slowly turned to the northeast, and deteriorated into a remnant low while situated over West Virginia. On September 18, the remnants of Florence emerged off the New England coast before being absorbed into a frontal system over the North Atlantic on September 19. In North Carolina, while moving forward at only 2–3 miles per hour, the storm continually dumped heavy rain along coastal areas. This, coupled with a large storm surge, caused widespread flooding along a long stretch of the North Carolina coast, from New Bern to Wilmington. As the storm moved inland from September 15 to 17, the heavy rain caused widespread inland flooding, inundating several cities, as major rivers all spilled over their banks. This flooding was exacerbated by earlier flooding during the summer that had left the ground heavily saturated. The city of Wilmington became entirely isolated, as all roads into and out of the city flooded and were deemed impassable. Many locations in the area received record-breaking rainfall, with more than 30 inches being measured in some. By the morning of September 16, Wilmington had recorded more rain from Florence than any other 2018 Hurricane Florence Flooding single weather event in the city’s history. Additionally, Florence contributed to the wettest year in Wilmington history, with annual rainfall totals eclipsing the previous record set in 1877. North Carolina’s Cape Fear River crested at 61.4 feet, about 35 feet above flood stage, near Fayetteville early on September 19. The nearby Little River inundated 219
large areas across Cumberland and Harnett counties. Overtopped bridges isolated communities and hampered relief efforts. Heavy rainfall also occurred in South Carolina, causing flooding there as well. Near Loris, 23.63 inches of precipitation set a new state record for rainfall from a tropical cyclone. At least 53 deaths have been attributed to this hurricane. The storm occurred so recently that insufficient time has passed for the compilation of accurate final data, but as of this writing, damages in North Carolina have been estimated at approximately $13 billion (2018 USD), with losses elsewhere still being tabulated.
A tsunami (sometimes inappropriately called a “tidal wave”) is a series of waves in a large body of water caused by the displacement of a significant volume of water. Earthquakes, volcanic eruptions and other underwater explosions—including detonations of underwater nuclear devices, landslides, glacier calvings, meteorite impacts, and such all have the potential to generate a highly destructive tsunami. Unlike normal ocean waves, which are generated by winds, or tides, which are caused by the gravitational pull of the Moon and the Sun, a tsunami is generated by the rapid displacement of water. Tsunami waves do not resemble normal undersea currents or normal ocean waves because their wavelength is far longer. Rather than appearing as a breaking wave, a tsunami may instead initially resemble a rapidly rising tide. Tsunamis generally consist of a series of waves, with periods ranging from minutes to hours. Wave heights of 30 or more feet are not uncommon. Although the impact of tsunamis is limited to coastal areas, their destructive power can be enormous, and they can affect entire ocean 220
basins. Offshore, tsunamis have a low wave height and a very long wavelength (often hundreds of miles, whereas normal ocean waves have a wavelength of only about 100 feet), which is why they generally pass unnoticed at sea, forming only a slight swell above the normal sea surface. When tsunamis reach shallower water, however, they grow substantially in height. A tsunami can occur at any tidal state, and even at low tide, it can still inundate coastal areas. All waves have a positive and negative peak—that is, a ridge and a trough—and either may be the first to arrive when a tsunami strikes. If the first part to arrive at the shore is the ridge, a massive breaking wave or sudden flooding will be the first effect noticed on land. However, if the first part to arrive is a trough, the water recedes dramatically from the shoreline, exposing normally submerged areas. The withdrawal can exceed hundreds of yards, and people unaware of the danger sometimes remain near the shore to satisfy their curiosity or to collect fish from the exposed seabed. Some 2,500 years ago, a Greek historian speculated that tsunamis might be caused by earthquakes and, based on the 365 AD Crete Earthquake, a Roman historian described in detail the three main phases—earthquake, sea withdrawal, and ensuing wave—of the tsunami that devastated Alexandria on the Nile Delta. The understanding of tsunamis remained minimal until the 20th century and much still is unknown. Tsunamis occur only infrequently, primarily in Japan, Indonesia, and the Mediterranean. Those that are most noteworthy in modern history are discussed below. The 1908 Messina Earthquake and Tsunami, the epicenter of which was in the Straits of Messina, claimed more than 123,000 lives in Sicily and Calabria, and is 221
among the deadliest natural disasters to have occurred in modern Europe. The earthquake, which occurred on December 28 with a magnitude of 7.5, caused widespread damage, with destruction experienced within a 190-mile radius. The cities of Messina and Reggio Calabria were almost completely destroyed. About 10 minutes after the earthquake, the sea on both sides of the Strait suddenly withdrew 230 feet from the shore as a 39-foot tsunami formed. Three waves in succession then struck nearby coasts, impacting hardest along the Calabrian coast and inundating Reggio Calabria. The entire Reggio seafront was destroyed, and a great number of people who had gathered there perished. In Messina, the tsunami also caused more devastation and deaths. Many of the survivors of the earthquake had fled to the supposed relative 1908 Messina Tsunami safety of the seafront to escape their collapsing houses. The second and third tsunami waves, coming in rapid succession and higher than the first, raced over the harbor, smashed boats docked at the pier, and broke parts of the sea wall. After engulfing the port and rushing 100 yards inland beyond the harbor, the waves swept away people, ships that had been anchored in the harbor, fishing boats and ferries, and inflicted further damage on the structures within the zone that had remained standing after the earthquake shock. The Messina shoreline was irrevocably altered when large sections of the coast sank several feet into the sea. The 1946 Aleutian Islands Earthquake and Tsunami occurred near Unimak Island in the Aleutian Island chain of Alaska on April 1st. The earthquake had a magnitude 222
of 8.6 and produced an enormous wave that traveled across the Pacific Ocean at 500 miles per hour. Approximately 48 minutes after the earthquake, the resulting tsunami surged over the costal cliff at Scotch Cap, Unimak Island, to a height of 135 feet above sea level, destroying the newly built US Coast Guard lighthouse there and killing all five members of the lighthouse crew. Despite its enormous size at Scotch Cap, the tsunami had little effect on the Alaskan mainland because the Aleutian Islands absorbed the brunt of its power, shielding the mainland. The tsunami reached Hawaiian Islands 4.5 hours after the quake, with wave heights reaching an estimated maximum of 55 feet, 36 feet, and 33 feet on Hawaii, Oahu, and Maui, respectively. The waves caused extensive destruction along the shorelines of the islands, especially at Hilo, on the big island of Hawaii, where the city’s entire waterfront was destroyed. 1946 Aleutian Islands Tsunami (at Hilo, Hawaii) The death toll from the event was 165 people, and damages were approximately $336.6 million (2018 USD). The 1960 Valdivia Earthquake and Tsunami occurred off the coast of Chile on May 22, 1960. The earthquake, with a magnitude of 9.5, was the strongest ever recorded in the world. The tsunami, with waves up to 82 feet high, hit the Chilean coast within 15 minutes, causing enormous loss of life, damage to port infrastructures, and the destruction of many small boats. In addition to southern Chile, earthquake-induced tsunamis affected Hawaii, Japan, the Philippines, China, eastern New Zea223
land, southeast Australia, and the Aleutian Islands. The main tsunami crossed the Pacific Ocean at a speed of several hundred miles per hour and devastated Hilo, Hawaii. Waves as high as 35 feet were recorded 6,200 miles from the epicenter, and as far away as Japan and the 1960 Valdivia Tsunami Destruction Philippines. The death toll and damages arising from this widespread disaster are not certain, but the average of the published estimated fatalities from the earthquake and tsunami combined is about 3,500. This relatively low number, given the strength of the earthquake, is explained in part by the low population density in the region. The average of the published estimated damages is about $5.1 billion (2018 USD). The 1964 Great Alaskan Earthquake and Tsunami occurred on Good Friday, March 27. The earthquake, with a magnitude of 9.2, spawned a 220-foot tsunami in Shoup Bay off Valdez Inlet. Two types of tsunamis were produced by this earthquake—a large tectonic tsunami and about 20 smaller local tsunamis. These smaller tsunamis were produced by submarine and subaerial landslides and were responsible for the majority of the tsunami damage. Tsunami waves were noted in over 20 countries, including Peru, New Zealand, Papua New Guinea, Japan, the Gulf of Mexico, and Antarctica. 1964 Great Alaskan Tsunami Destruction
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Most coastal towns in the Prince William Sound, Kenai Peninsula, and Kodiak Island areas—especially the major ports of Seward, Whittier, and Kodiak—were heavily damaged by a combination of seismic activity, subsidence, post-quake tsunamis, and/or earthquakecaused fires. Port Valdez suffered a massive underwater landslide, resulting in the deaths of 30 people. Nearby, a 27-foot tsunami destroyed the village of Chenega, killing 23 of the 68 people who lived there. Valdez was not totally destroyed, but after 3 years, the town relocated to higher ground 4 miles west of its original site. The number of people who perished as a result of the earthquake is believed to have been 139. Fifteen died as a result of the earthquake itself, 106 died from the subsequent tsunami in Alaska, 5 died from the tsunami in Oregon, and 13 died from the tsunami in California. Property damage was estimated at about $2.5 billion (2018 USD). The 2004 Indian Ocean Earthquake and Tsunami occurred on December 26 off the west coast of Sumatra, Indonesia, in the Indian Ocean. The earthquake, with a magnitude of 9.2, was the third-largest earthquake (after the 1960 Valdivia Earthquake and the 1964 Alaska Earthquake) ever recorded on a seismograph. The accompanying tsunami was the deadliest the world has ever experienced. Within 15 minutes of the quake, tsunami waves were crashing ashore on Sumatra, and at Aceh, those waves reached 80 feet high over large stretches of the coast, and up to 100 feet high in some places, while traveling as far as 1.2 miles inland. Entire communities were swept away by the water in a matter of minutes. The huge waves missed the north coast of Indonesia, and went on to Thailand, where 5.395 people were killed. The tsunami also moved east across the Indian Ocean and, in Sri 225
2004 Indian Ocean Tsunami
Lanka, it came ashore about 90 minutes after the earthquake killing approximately 35,322 people. In addition, 12,405 people died in India. The killer waves even reached South Africa, 5,000 miles away, where 2 people
perished. The total death toll for the earthquake and tsunami was approximately 230,000, primarily caused by the tsunami. The estimated financial damages were about $13.4 billion (2018 USD). The 2011 Tōhoku Earthquake and Tsunami occurred on March 11, off the east coast of the Tohoku Region of Japan. The earthquake, with a magnitude of 9.0, triggered powerful tsunami waves that reached heights of up to 133 feet and traveled inland as much as 6 miles, bringing destruction along the Pacific coastline of Japan’s northern islands. The tsunami propagated throughout the Pacific Ocean reaching the entire Pacific coast of North and South America from Alaska to Chile, but the extent of the damage there was relatively minor. Chile’s Pacific coast, one of the furthest from Japan at about 11,000 miles distant, was struck by waves 6.6 feet high. In California and Oregon, tsunami surges up to 7.9 feet high hit some areas, damaging docks and harbors and causing several million dollars in damage. The tsunami broke icebergs off the Sulzberger Ice Shelf in Antarctica, 8,100 miles away; a total of 48 square miles of ice broke away, with the main iceberg measuring 5.9 x 4.0 miles (approximately the area of Manhattan Island) and about 260 feet thick. 226
The damage caused by the tsunami, though much more localized, was far more deadly and destructive than the earthquake itself. The tsunami inundated a total area of approximately 217 square miles in Japan, and thousands of lives were lost when entire towns were devastated by the waves. This tsunami was much larger than coastal protection planners had anticipated it might be, and although Japan had spent considerable money on anti-tsunami seawalls, which line at least 40% of its 21,593-mile coastline and stand up to 39 feet tall, the tsunami simply washed over the top of many of them, collapsing some in the process. More than 100 designated tsunami evacuation sites were inundated by the onslaught. The tsunami caused several nuclear accidents, primarily the level-7 (major) meltdowns of three reactors in the Fukushima Daiichi Nuclear Power Plant complex. While 16 miles of 2011 Tohoku Tsunami tsunami barriers walls Overtopping Seawall had been built specifically to protect the plant, the tsunami toppled more than 50% of them and caused catastrophic damage. The meltdowns resulted from cooling system failures caused by the loss of electrical power when the emergency diesel generators were disabled by the tsunami. The Japanese government estimated that the tsunami swept about 5 million tons of debris offshore, claiming that 70% sank, leaving 1.5 million tons floating in the Pacific Ocean. Some of this wreckage has come ashore, including a soccer ball that was found in Alaska, and a Japanese motorcycle found in British Columbia. In 2012, 227
the US Coast Guard came across a derelict ship, the 164foot Ryou-Un Maru, in the Gulf of Alaska, which it sank by firing upon it. Approximately 18,000 people died or went missing as a result of the Tohoku event. The financial damages from the earthquake and tsunami combined have been estimated to be about $235 billion (2018 USD).
A megatsunami is a particular type of tsunami. Since “mega” essentially means “large,” and since a “tsunami” is a “large wave,” a megatsunami is a “very large wave.” But megatsunamis aren’t just bigger than “ordinary” tsunamis—their features are quite different. Ordinary tsunamis are caused by tectonic activity, and the waves are the result of water being displaced by the rise or fall of the sea floor. They have low waves out at sea, and the water piles up to a wave height of as much as 33 feet when the sea floor becomes shallow near land. By contrast, megatsunamis occur when a very large amount of material falls suddenly into water (such as via a landslide, volcanic explosion, or meteor impact). They can have extremely high initial wave heights of hundreds and possibly thousands of feet, far beyond any ordinary tsunami, as the water is “splashed” upwards and outwards by the impact or displacement. Consequently, two heights are sometimes quoted for megatsunamis— the height of the wave itself (in water), and the height to which it surges when it reaches land, which, depending upon the locale, can be several times larger. Megatsunamis are rare events, and it wasn’t until 1958 that their existence was confirmed by a giant landslide in Lituya Bay, Alaska, which caused the highest wave (over 228
1,700 feet) ever recorded. Four megatsunamis that have occurred in modern history are discussed below. The 1883 Krakatoa Eruption Megatsunami was the result of the eruption of Mount Krakatoa in Indonesia on August 27, 1883. The eruption, which destroyed over two-thirds of the island and ejected approximately 6 cubic miles of rock, was among the most violent volcanic events in recorded history. The explosion is considered to be the loudest sound ever heard in modern history, with reports of it being heard up to 3,000 miles away. The eruption created pyroclastic flows, which generated megatsunamis when they hit the waters of the Sunda Strait. The maximum wave heights reached 140 feet, wiping out 165 villages and towns and killing more than 36,000 1883 Krakatoa Eruption people. The 1958 Lituya Bay Megatsunami, which occurred in a remote southeast Alaska bay on July 9, was the result of a Magnitude 7.8 earthquake, which caused an enormous landslide containing 40 million cubic yards of material. The landslide dropped several hundred yards of it almost vertically, and it hit the water with sufficient force to break off and uplift 1,300 feet of ice from the Lituya Glacier and create a giant wave—the tallest ever recorded. This wave surged up the opposite side of Gilbert Inlet at the head of the bay to a height of 1,720 feet, stripping away all of the trees. In the bay itself, the wave was still 50 to 100 feet high as the displaced water surged toward the Gulf of Alaska.
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There were three boats anchored in the bay that evening. One of them rode out the wave; a second was damaged and later sank, but the passengers survived; and the third, with two people aboard, vanished without a trace, carried by the tsunami out into the open sea. The 1963 Vajont Dam Megatsunami occurred on October 9, 1963, when a massive landslide of about 340
1959 Lituya Bay Megatsunami – Map of the Bay
million cubic yards from Monte Toc, traveling at speeds up to 68 miles per hour, entered the 220-million-cubicyard lake behind the 860 foot high dam (one of the tallest in the world). The landslide, which lasted only 45 seconds, completely filled the narrow reservoir behind the dam, causing 65 million cubic yards of 230
1963 Vajont Dam Tsunami – After the Wave
water to overtop the dam in an 820-foot-high wave. The megatsunami completely destroyed several villages and towns downstream in the Piave Valley and resulted in 1,910 deaths. It turned the land below the dam into a flat plain of mud with an impact crater 200 feet deep and 260 feet wide. The dam remained almost intact, and two thirds of the water was retained behind it. Today it is still standing and has become a tourist attraction. The 1980 Spirit Lake Megatsunami was caused by the volcanic eruption of Mount St. Helens in Washington State on May 18, 1980. The upper 1,509 feet of the mountain collapsed, creating a massive landslide; and one lobe of the avalanche surged onto Spirit Lake, causing a megatsunami that surged to a maximum height of 853 feet above the pre-eruption water level. As the water returned to the basin, the debris avalanche deposited about 560 million cubic yards of pyrolyzed trees, other plant material, volcanic ash, and volcanic debris of various origins into the lake. The deposition of this debris decreased the lake’s volume by approximately 73 million cubic yards. Lahar and pyroclastic flow deposits from the eruption blocked the lake’s natural pre-eruption outlet to the North Fork Toutle River valley, raising the surface elevation of the lake by approximately 200 feet. The surface area of the lake was increased from 1980 Spirit Lake Megatsunami – Log Mat 1,300 acres to about 2,200 acres, and its maximum depth decreased from 190 feet to 110 feet. The thousands of shattered trees formed a floating log mat 231
that covered about 40% of the lake’s surface after the eruption and still exists to this day, almost four decades after the event.
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Chapter 19
Dealing With Floods We humans have an incredible ability to control the world around us. We can move mountains and land robots on other planets. We can keep each other alive longer than ever before and even bring entire species back from the brink of extinction. But despite all of our giant steps forward, we’re still unable to control the weather, a tremendous force that affects every human being on this planet. We have been trying to do so for centuries, but with negligible success. The most common goal has been that of creating more rain or snow, usually for the purpose of increasing the local water supply. Another weather modification goal has been that of preventing damaging weather, such as hurricanes, from occurring. Attempts have been made to provoke damaging weather against enemies, as a tactic of military or economic warfare, but that has now been banned by the United Nations. While we cannot control the weather, we can change the weather; and we are, in fact, doing just that today through the unintentional process of “Global Warming.” Global Warming, which is believed to result in more extreme weather patterns, will be discussed in the next chapter.
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Given that we can’t control the causes of floods, the best we can do is to attempt to minimize the casualties and the damage that they cause. At the most basic level, the best defense is for people to avoid occupying flood hazard zones—to not build in or reside in them. In less-developed countries, that’s not realistic because subsistence-level fishermen and farmers need to live in areas that support their livelihood. In developed nations, however, it’s a viable objective—except, perhaps, with respect to the “entitled” who choose to buy homes in scenic locales along rivers, beaches, and lakes despite the risks. Building should be done on higher ground in general; and critical community-safety facilities, such as hospitals, emergency-operations centers, and police, fire, and rescue services, should definitely be located in areas least at risk for flooding. Areas most at risk for flooding could be put to uses such as parks, playgrounds, and such, that could tolerate occasional flooding and be abandoned temporarily as people retreat to safer locations when a flood is imminent. Structures, such as bridges, which must unavoidably be in flood hazard areas, should be designed to withstand flooding. Along rivers, streams, and the like, defenses such as detention basins, levees, bunds, reservoirs, and weirs are used to prevent waterways from overflowing their banks. When these defenses fail, emergency measures such as sandbags or portable inflatable tubes are often used to try to stem flooding. Coastal flooding has been addressed in some places with coastal defenses, such as sea walls, beach replenishment, and barrier islands. When it comes to urban (surface) flooding, one approach is the repair and expansion of man-made sewer systems and stormwater infrastructure. Another strategy is to reduce impervious surfaces in streets, parking lots, and buildings 234
through natural drainage channels, porous paving, and wetlands. Anticipating floods before they occur allows for precautions to be taken and people to be warned so that they can be prepared in advance for flooding conditions. If necessary, people can be evacuated. Moreover, farmers can relocate animals from low-lying areas, and utility companies can put in place emergency measures to reroute services if needed. Emergency services can also make provisions to have enough resources available ahead of time to respond to emergencies as they occur. Flood forecasting is a critical element in the minimizing of human fatalities during a flood. Flood forecasters rely heavily on real-time data about rainfall and river water levels as well as rainfall forecasts. Rain gauges are used to monitor rain that has fallen on the catchment area; water levels along the river are also measured; and the forecasters then use hydrological computer models to work out how much rainfall will run off different parts of the catchment, how long it will take for runoff to reach the river, how long that water will take to travel from upstream to downstream, and how water from different tributaries converges in the river network. Reliable forecasts of weather—in particular, rainfall— can allow advance warning and forecasting of floods. Humans have attempted to predict the weather informally for millennia and formally since the 19th century. Once a human-only endeavor based mainly upon changes in barometric pressure, current weather conditions, and sky condition or cloud cover, weather forecasting now relies on computer-based models—often with quantitative data input from radar, reconnaissance aircraft, and satellites that take many atmospheric factors into account. However, human input is still required to 235
pick the best possible meteorological model upon which to base the forecast. The inaccuracy of forecasting is due to the chaotic nature of the atmosphere, the massive computational power required to solve the equations that describe the atmosphere, the error involved in measuring the initial conditions, and an incomplete understanding of atmospheric processes. Consequently, forecasts become less accurate as the difference between the current time and the time for which the forecast is being made increases. A major part of modern weather forecasting is the severe weather alerts and advisories that national weather services issue in the event that severe or hazardous weather is expected. Once flooding begins in an urban or developed area, there’s little that can be done to protect property, so all efforts are focused on rescue and the prevention of fatalities. While lightning, tornadoes, and hurricane winds can have deadly consequences, floods—particularly the kind that inundate city streets and buildings—are the leading cause of weather-related deaths in the US. Floodwaters cause nearly as many fatalities each year as the other three combined, a stark reality that makes flood response all the more critical. Floodwater rescue teams are usually made up of members of a community’s fire, police, or ambulance departments who have been cross-trained in basic waterrescue techniques. There may also be volunteers who have received similar training. In some situations, elite teams of specially trained flood rescuers may be mobilized as part of a regional or national response. Tools used by rescue teams might include search and rescue dogs, mounted search and rescue horses, helicopters, rescue boats, and heavy rescue vehicles. Rescuing floodwater victims is not as simple as sidling a boat up to a building. Rushing water makes it 236
nearly impossible to safely transfer a person from a stationary object onto an undulating boat, so rescuers must learn hydrology, especially how water acts when it is moving quickly through a confined channel. They need to learn how to read maps when most normal landmarks are not visible, and to navigate their rescue boats Floodwater Rescue through city streets while contending with buildings, vehicles, hidden snags, and dangerous debris. They often have to perform the same rescue operation over and over again until everyone stranded has been transported to safety. Rescue boats can only fit three or four passengers in addition to the crew, so teams will first take the young, old, and injured to safety—sometimes performing first aid in the process. Once those who have been rescued reach land, they are transferred to relief agencies that will provide medical care, food, shelter, and other assistance. The need for effective response continues long after the flood waters begin to recede. Essential services such as power, water, sewage, and gas may not be working. There could also be road and rail damage, lack of public transport, airport closures, and loss of telecommunications. Affected areas are often blanketed in silt and mud; the water and landscape can be contaminated with hazardous materials—such as sharp debris, pesticides, fuel, and untreated sewage—and polluted drinking water can lead to outbreaks of deadly waterborne diseases like typhoid, hepatitis A, and cholera. Emergency responders are likely to be onsite for only a short period of time—hours or days—so rapid implementation of arrangements for collaboration, co-ordina237
tion, and communication with longer-term responders are therefore vital. These are the organizations that help meet the basic needs of survivors until more permanent and sustainable solutions can be implemented. The common objectives of these responders include: (1) containing or mitigating the effects of an event to prevent any further loss of life and/or property; (2) restoring order and community self-sufficiency in its immediate aftermath; and (3) re-establishing normality through reconstruction and rehabilitation so as to restore critical activities and normal services. The main responsibility for addressing these needs lies with the government or governments of the territory in which the disaster occurs. On a national level, in the United States, the Federal Emergency Management Agency (FEMA) coordinates federal operational and logistical disaster response capability needed to save and sustain lives, minimize suffering, and protect property in a timely and effective manner in communities that become overwhelmed by disasters. The Centers for Disease Control and Prevention (CDC) offer information for specific types of emergencies, such as disease outbreaks, natural disasters, and severe weather, as well as chemical and radiation accidents. Additionally, private humanitarian aid organizations are often very much present in this phase of the disaster management cycle, particularly in countries where the government lacks the resources to respond adequately to the needs. Among such organizations, in the US, the American Red Cross is chartered by Congress to lead and coordinate non-profit efforts. They are backed up by disaster relief organizations from many religious denominations and community service agencies.
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Chapter 20
Global Climate Change and Flooding The Earth and its atmosphere are unquestionably warming. Politics aside, that’s a data-based, proven, scientific fact—one that is not disputed by any scientific body of national or international standing. The planet’s average surface temperature has risen about 1.62 degrees Fahrenheit since the late 19th century, with most of that increase occurring over just the past 35 years; 16 of the 17 warmest years on record have occurred since 2000. Most scientists agree that this increase is driven largely by the human-generated release of carbon dioxide and other “greenhouse-effect” emissions into the atmosphere. Depending on the choices that humans make with respect to energy consumption and energy production, indications are that by the end of the 21st century, the average global surface temperature will rise by another 1.0 to 6.0oF. As the planet warms, flooding will presumably become a more widespread problem. The mechanism driving such changes is well understood. Warmer air can hold more water vapor than cooler air, so the heaviest precipitation events are likely to become even heavier as air temperatures increase. Since 1991, the amount of 239
rain falling in very heavy precipitation events has been significantly above historical averages. In the US, this increase has been greatest in the Northeast, Midwest, and upper Great Plains—more than 30% above the 1901–1960 average. There has also been an increase in flooding events in the Midwest and Northeast, where the largest increases in heavy rain amounts have occurred. In glacial areas, climate change is likely to contribute to devastating floods more directly. Melting glaciers can put additional pressure on the natural dams that retain meltwater. When these dams fail, they can cause sudden and catastrophic outburst floods that send water cascading into narrow valleys below. For example, in June 2016, a glacial outburst flood at the Lhotse Glacier near Mount Everest released about 2.5 million cubic yards of water from within the glacier itself. Another situation in which relatively cold areas are especially vulnerable to flooding caused by warming is that of a particularly destructive kind of extreme weather event called a “rainon-snow” flood. Common in mountain regions—and increasing as temperatures rise—these events happen when heavy rains fall on top of deep snowpack, melting it and triggering intense floods. California’s Sierra Nevada Mountains, the Rocky Mountains west of Denver, and parts of the Canadian Rockies are especially at risk. In addition to increasing the likelihood of major floods, the activities of humans are also increasing the risks associated with those floods. With unabated urbanization and human alteration of the land—like the engineering of rivers, the destruction of natural protective systems, and increased construction on floodplains and in coastal areas—many parts of the United States have been put at greater risk for experiencing very destructive and costly floods. 240
Much flooding is in the form of coastal floods caused by hurricanes, and whether a hurricane causes a flood or not, is often a function of anthropogenic factors. Since the early 1980s, there has been a substantial increase in most measures of Atlantic hurricane activity. These include measures of intensity, frequency, and duration as well as the number of both strongest (Category 4 and 5— there have been 14 of them in the 21st century alone) and costliest (adjusted for inflation, 5 of the 10 most expensive hurricanes in US history have occurred since 1990) storms. These recent increases in activity are linked, in part, to higher sea surface temperatures in the regions where Atlantic hurricanes form and move through. In addition, potential hurricane destructiveness—a measure combining hurricane strength, duration, and frequency— has been shown to be highly correlated with tropical sea surface temperature. Hurricane development, however, is influenced by more than just sea surface temperature. How hurricanes develop also depends on how the local atmosphere responds to changes in local sea surface temperatures, and this atmospheric response depends critically on the cause of the change. Several studies published in the last decade have shown that, while the number of tropical cyclones worldwide has decreased in the last 35 years or so, there has been a large increase in the number and proportion of very powerful storms, particularly over the North Atlantic and Indian Oceans. Between 1981 and 2006, wind speeds for the strongest tropical storms increased from an average of 140 miles per hour to 156 miles per hour, while the ocean temperature, averaged globally over all the regions where tropical cyclones form, increased from 82.8 °F to 83.3 °F. As well, the energy released by the average hurricane worldwide appears to have increased by around 70% in that same time frame. This corresponds to 241
about a 15% increase in the maximum wind speed and a 60% increase in storm duration. Given that global warming is expected to continue, this pattern of increasingly powerful hurricanes is also expected to continue, and the strongest hurricanes we have experienced to date are likely to be upstaged any number of times before the end of the century.
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Section V
Infernal Wildfires
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Chapter 21
Wildfires in General A wildfire is a fire that involves a large area of combustible vegetation. Depending on the type of vegetation where it occurs, a wildfire can be classified more specifically as a peat fire, desert fire, veld fire, grass fire, vegetation fire, brush fire, bush fire, or forest fire. Fossil charcoal indicates that wildfires began soon after the appearance of terrestrial plants on Earth some 420 million years ago. The occurrence of wildfires throughout the history of terrestrial plant life suggests that fire must have had pronounced evolutionary effects on most ecosystems’ flora and fauna. Earth is an intrinsically flammable planet due to its cover of carbon-rich vegetation, seasonally dry climates, atmospheric oxygen, and widespread lightning and volcanic ignitions. Wildfires are common in climates that are sufficiently moist to allow the growth of vegetation but feature extended dry, hot periods. Wildfire initiation, behavior, and severity result from a combination of factors such as: • Cause of ignition – While lightning and volcanic eruption are the most common natural causes, four out of five wildfires are started by people. 245
The most common direct human causes of wildfire ignition include arson, discarded cigarettes, power-line arcs, and sparks from equipment. In less-developed agricultural communities, wildfires can also be started by the use of fire for clearing land.
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Available fuels – A high moisture content in vegetation usually prevents ignition and slows propagation, because higher temperatures are required to evaporate any water within the material and heat the material to its fire point. Dense forests usually provide more shade, resulting in lower ambient temperatures and greater humidity, and are therefore less susceptible to wildfires. Less dense material, such as grasses and leaves, are easier to ignite because they contain less water than denser material such as branches and trunks.
•
Physical setting – Fuel arrangement and density is governed in part by topography, as land shape determines factors such as available sunlight and water for plant growth. Wildfires have a rapid forward rate of spread when burning through dense, uninterrupted fuels. They can move as fast 6.7 miles per hour in forests and 14 miles per hour in grasslands. Wildfires can advance tangential to the main front to form a flanking front, or burn in the opposite direction of the main front by backing. They may also be spread as winds and vertical convection columns carry firebrands and other burning materials through the air over roads, rivers, and other barriers that may otherwise act as firebreaks.
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Weather – Analyses of historical meteorological data and national fire records in western North
America show the primacy of climate in driving large regional fires. Heat waves, droughts, cyclical climate changes such as El Niño, and regional weather patterns such as high-pressure ridges can increase the risk and alter the behavior of wildfires dramatically. Years of precipitation followed by warm periods can encourage more widespread fires and longer fire seasons. Since the mid1980s, earlier snowmelt and associated warming has also been associated with an increase in the length and severity of the wildfire season in the western United States. Global warming may increase the intensity and frequency of droughts in many areas, creating more intense and frequent wildfires. Intensity also increases during daytime hours. Burn rates of smoldering logs are up to five times greater during the day due to lower humidity, increased temperatures, and increased wind speeds. Sunlight warms the ground during the day, creating air currents that travel uphill. At night, the land cools, creating air currents that travel downhill. Wildfires are fanned by these winds and often follow the air currents over hills and through valleys.
Lightning Strike and Wildfires
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Overall, fire types can be generally characterized by their fuels as follows: • Ground fires are fueled by subterranean roots and other buried organic matter. Ground fires typically burn by smoldering, and can burn slowly for days to months. • Surface fires are fueled by low-lying vegetation on the forest floor such as leaf and timber litter, debris, grass, and low-lying shrubbery. This kind of fire often burns at a relatively lower temperature (less than 752 °F) than crown fires and may spread at a slow rate, though steep slopes and wind can accelerate the rate of Surface Fire spread. • Ladder fires consume material between low-level vegetation and tree canopies, such as small trees, downed logs, and vines. Kudzu, Old World climbing fern, and other invasive plants that scale trees may also encourage Ladder Fire ladder fires. • Crown fires burn suspended material at the canopy level, such as tall trees, vines, and mosses. The ignition of a crown fire, termed crowning, is dependent on the density of the suspended material, canopy height, canopy continuity, sufficient 248
surface and ladder fires, vegetation moisture content, and weather conditions during the blaze. Crown Fire A wildfire front is the portion of the fire that sustains continuous flaming combustion, where unburned material meets active flames, or the smoldering transition between unburned and burned material. As the front approaches, the fire heats both the surrounding air and woody material through convection and thermal radiation. First, wood is dried as water is vaporized at a temperature of 212 °F. Next, the thermal decomposition of wood at 450 °F releases flammable gases. Finally, wood can smolder at 720 °F or, when heated sufficiently, ignite at 1,000 °F. Even before the flames of a wildfire arrive at a particular location, heat transfer from the wildfire front can heat the air to 1,470 °F, which pre-heats and dries flammable materials, causing materials to ignite faster and allowing the fire to spread more rapidly. High-temperature and long-duration surface wildfires may encourage flashover with the drying of tree canopies and their subsequent ignition from below. Especially large wildfires may affect air currents in their immediate vicinities because heated air rises, and large wildfires create powerful updrafts that Fire Whirl
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will draw in new, cooler air from surrounding areas in thermal columns. Great vertical differences in temperature and humidity encourage pyrocumulus clouds, strong winds, and fire whirls with the force of tornadoes at speeds of more than 50 miles per Pyrocumulus Cloud hour. While humans generally think of wildfires in negative terms because they cause property damage and loss of life, wildfires have many beneficial effects on native vegetation, animals, and ecosystems that have evolved with fire. High-severity wildfires create complex early seral forest habitats, which often have higher species richness and diversity than unburned old forest. Many plant species depend on the effects of fire for growth and reproduction. Fire helps to return nutrients from plant matter back to the soil, the heat from fire is necessary to the germination of certain types of seeds, and the dead trees and early successional forests created by high-severity fire create habitat conditions that are beneficial to wildlife. Plants in wildfire-prone ecosystems often survive through adaptations to their local fire regime. Such adaptations include physical protection against heat, increased growth after a fire event, and flammable materials that encourage fire and may eliminate competition. For example, eucalyptus plants contain flammable oils that encourage fire, but they also have small, thick, and leathery leaves that reduce water loss and help them resist heat and drought, thus ensuring their dominance over 250
less-fire-tolerant species. Dense bark, shedding lower branches, and high water content in external structures may also protect trees from rising temperatures. Fire-resistant seeds and reserve shoots that sprout after a fire encourage species preservation. Smoke, charred wood, and heat can stimulate the germination of seeds in a number of plant species. While some ecosystems rely on naturally occurring fires to regulate growth, others suffer from too much fire, such as the chaparral in southern California and lower elevation deserts in the American Southwest. The increased fire frequency in these ordinarily fire-dependent areas has upset natural cycles, damaged native plant communities, and encouraged the growth of non-native weeds. Invasive species can grow rapidly in areas that were damaged by fires. Because they are highly flammable, they can increase the future risk of fire, creating a positive feedback loop that increases fire frequency and further alters native vegetation communities. Most of the Earth’s weather and air pollution is located in the troposphere, the part of the atmosphere that extends from the surface of the planet to a height of about 6 miles. The vertical lift of a severe thunderstorm or cumulonimbus cloud can be enhanced in the area of a large wildfire, resulting in the formation of a pyrocumulonimbus cloud, which can propel smoke, soot, and other particulate matter as high as 25,000 feet, affecting local atmospheric pollution and releasing large quantities of carbon dioxide. A pyrocumulonimbus cloud is much like a cumulonimbus cloud, but with considerably more vertical development. Such a cloud may involve precipitation, hail, lightning, extreme low-altitude winds, and in some cases, even tornadoes. During the 2003 Canberra bushfires in Australia, a supercell thunderstorm formed from a pyrocumulonimbus cloud, resulting in a large fire 251
tornado rated at EF3 on the Fujita scale, making it the first confirmed violent fire tornado. The tornado and associated fire killed 4 people and injured 492.
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Chapter 22
Wildfire Prevention Wildfire prevention starts with preemptive methods aimed at reducing the risk of fires as well as lessening their severity and spread. Prevention techniques aim to manage air quality, maintain ecological balances, protect resources, and affect future fires. Strategies of wildfire prevention, detection, and suppression have varied over the years. Wildland fire use—permitting naturally caused fires to continue to burn in order to maintain their ecological role, as long as the risks of escape into highvalue areas are mitigated—is the least expensive and most ecologically appropriate policy for many forests. One common and inexpensive technique is controlled burning—i.e., permitting or even igniting smaller fires to minimize the amount of flammable material available for a potential wildfire. Fuels may also be removed by logging, but fuel treatments and thinning have no effect on severe fire behavior under extreme weather conditions. Building codes in fire-prone areas typically require that structures be built of flame-resistant materials and that a defensible space be maintained by clearing flammable materials within a prescribed distance from the structure.
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In 1937, US President Franklin D. Roosevelt initiated a nationwide fire prevention campaign highlighting the role of human carelessness in forest fires. Later posters of the program featured Uncle Sam, characters from the Disney movie Bambi, and the official Smokey Bear Poster mascot of the US Forest Service, Smokey Bear, who asserted, “Only you can prevent forest fires.” Reducing human-caused ignitions may be the most effective means of reducing unwanted wildfires. Fast and effective Bambi in Forest Fire detection is a key factor in preventing major wildfires. Historical detection efforts were focused on early response, accurate location in both daytime and nighttime, and the ability to prioritize fire danger. Fire lookout towers were used in the United States in the early 20th century, and fires were reported using telephones, carrier pigeons, and heliographs. Aerial and land photography using instant cameras Fire Lookout Tower 254
were used in the 1950s until infrared scanning was developed for fire detection in the 1960s. Information analysis and delivery, however, was often delayed by limitations in communication technology. Early satellite-derived fire analyses were hand-drawn on maps at a remote site and sent via overnight mail to the fire manager. Currently, public hotlines, fire lookouts in towers, and ground and aerial patrols can be used as a means of early detection of forest fires. However, accurate human observation may be limited by operator fatigue, time of day, time of year, and geographic location. Electronic systems have gained adherents in recent years as a possible resolution to human operator error, but studies have shown that detection by such systems is still slower and less reliable than those of trained human observers. These systems may be semi- or fully automated and employ methodologies based on the risk area and degree of human presence. An integrated approach of multiple systems can be used to merge satellite data, aerial imagery, and personnel positioning via Global Positioning System into a collective whole for nearly real-time use by wireless Incident Command Centers. Small, high- risk areas that feature thick vegetation, a strong human presence, or are close to a critical urban area can be monitored using a local wireless sensor network that detects temperature, humidity, and smoke. Larger, medium-risk areas can be monitored by scanning towers that incorporate fixed cameras and sensors to detect smoke or additional factors such as the infrared signature of carbon dioxide produced by fires. Additional capabilities such as night vision, brightness detection, and color-change detection may also be incorporated into sensor arrays. Satellite and aerial monitoring through the use of planes, helicopters, or unmanned aerial vehicles 255
(UAV) can provide a wider view and may be sufficient to monitor very large, low-risk areas. These more sophisticated systems employ global positioning system (GPS) and aircraft-mounted infrared or high-resolution visual cameras to identify and target wildfires. Satellite detection, however, is prone to offset errors, anywhere from 1 to 7.5 miles depending on the system. Satellites in geostationary orbits may become disabled, and satellites in polar orbits are often limited by their short window of observation time. Cloud cover and image resolution may also limit the effectiveness of satellite imagery.
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Chapter 23
Wildfire Suppression Wildfires in the United States burn an average of 7 million acres of land each year. For the last 10 years, the US Forest Service and Department of Interior have spent a combined average of about $2–4 billion annually on wildfire suppression. Techniques of wildfire suppression depend on the technologies available in the area in which the wildfire occurs. In less developed nations, they can be as simple as throwing sand or beating the fire with sticks or palm fronds. In more advanced nations, the suppression methods vary depending on technological capacity. Approaches can include the use of silver iodide to seed clouds and encourage snow fall, as well as dropping fire retardants and water onto fires by unmanned aerial vehicles, planes, and helicopters. Fire retardants are aqueous solutions of ammonium phosphates Aerial Spraying of Fire Retardant and ammonium sulfates, as well as thickening agents, and are used to slow wild257
fires by inhibiting combustion. The decision to apply retardant depends on the magnitude, location, and intensity of the wildfire. Complete fire suppression is no longer an expectation, but the majority of wildfires are often extinguished before they grow out of control. While more than 99% of the 10,000 new wildfires each year are contained, escaped wildfires under extreme weather conditions are extremely difficult to suppress without a change in the weather. Wildfires in Canada and the US combined burn an average of 13,000,000 acres per year. Of primary importance in the work to suppress wildfires is the recognition that a wildfire can become deadly at any moment. A wildfire’s burning front may change direction unexpectedly and jump across fire breaks. Intense heat and smoke can cause firefighters to become disoriented and lose of awareness of the direction in which the fire is heading. For example, during the 1949 Mann Gulch fire in Montana, 13 smokejumpers died when they lost their communication links, became disoriented, and were overtaken by the fire. In the Australian February 2009 Victorian bushfires, at least 173 people died and over 2,029 homes and 3,500 structures were lost when they became engulfed by wildfire. Wildland firefighters face several other lifethreatening hazards, including heat stress, fatigue, smoke and dust, as well as the risk of injuries from vehicles, equipment, and falling objects. They are also at risk for cardiac events including strokes and heart attacks, fractures, sprains, burns, cuts and scrapes, and animal bites. Especially in hot weather conditions, fires present the risk of heat stress, which can progress into heat strain, and then into heat stroke. Various factors can contribute to the risks posed by heat stress, including strenuous work, personal risk factors such as age and fitness, dehydration, 258
sleep deprivation, and burdensome personal protective equipment. Rest, cool water, and occasional breaks are crucial to mitigating the effects of heat stress. Firefighters are especially prone to rhabdomyolysis, which can be caused by exertion and becoming overheated. It involves the breakdown of damaged muscle tissue that releases proteins and electrolytes into the blood, and can damage the heart and kidneys, result in permanent disability, and can even be fatal. Smoke, ash, and debris can also pose serious respiratory hazards to wildland firefighters. The smoke and dust from wildfires can contain toxic gases such as carbon monoxide, sulfur dioxide and formaldehyde, as well as particulates such as ash and silica. Wearing personal protective equipment can help to mitigate many of these hazards, but such equipment is quite expensive and firefighters are often sent into action without all the appropriate gear. Between 2000 and 2017, 313 fatalities were recorded for US wildland firefighters. The most noticeable The Cost of Personal adverse effect of wildfires is Protective Equipment the destruction of property. What is often not recognized is that the release of hazardous chemicals from the burning of wildland fuels also significantly impacts health in humans. Wildfire smoke is composed primarily of carbon dioxide and water vapor. Other common smoke components present in lower concentrations are carbon monoxide, formaldehyde, acrolein, polyaromatic 259
hydrocarbons, and benzene, and small particulates. Moreover, 80–90% of wildfire smoke, by mass, is made up of small particulates. Despite carbon dioxide’s high concentration in smoke, it poses a low health risk due to its low toxicity. On the other hand, carbon monoxide and fine particulate matter, particularly that 2.5 micrometers in diameter and smaller, have been identified as the major health threats. Other chemicals are considered to be significant hazards but are found in concentrations that are too low to cause detectable health effects. The degree of wildfire smoke exposure for an individual is dependent on the length, severity, duration, and proximity of the fire. Another important and somewhat less obvious health effect of wildfires is psychiatric disorders. These include post-traumatic stress disorder (PTSD), depression, anxiety, and phobias.
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Chapter 24
Specific Noteworthy Wildfires Wildfires can be classified as “major” either because of their size or because of their death toll. The number of acres burned in a major wildfire can be astonishing—frequently in the millions.† This is so, in part, because wildfires are often permitted to continue to burn, as long as they remain under control, in order to maintain the normal ecological balance in the area. The five largest recorded wildfires are, in ascending order: The Great Fire of 1919 in western Canada (5 million acres); the 1939 Black Friday Bushfires in Australia (5 million acres); the 1989 Manitoba Wildfires in central Canada (8.1 million acres); the 2014 Northwest Territories Fires in northern Canada (8.4 million acres); and the 2003 Siberian Taiga Fires in Russia (47 million acres!). Those that are con†
Most of us have only a vague idea of just how big 1,000,000 acres (1,562 square miles) really is. To put that number into perspective, one approach is to recognize that the average tract home is built on a ¼ acre lot and 1 million acres would accommodate 4 million of them. Given that an average household consists of 2.5 people, 10 million people could live comfortably on that amount of land. Another approach would be to think in terms of roads. The average 2-lane paved road is 30 feet wide, so 1 mile of such a road would cover 4 acres. That means that it would take 250,000 miles of such roads to cover 1,000,000 acres—enough to stretch around the globe at the equator 10 times.
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trolled are not particularly interesting and therefore not especially noteworthy. The five most deadly recorded wildfires are, in ascending order: the 2009 Black Saturday Bushfires in Australia (173 fatalities); the 1881 Thumb Fire in Michigan (282 fatalities); the 1894 Great Hinkley Fire in Minnesota (418 fatalities); the 1918 Cloquet in Minnesota Fire (1000+ fatalities); and the 1871 Peshtigo Fire in Wisconsin/Michigan (1500 fatalities). The number of fatalities caused by each major wildfire is much lower than that caused by other types of major natural disasters—usually less than 100, as opposed to hundreds in tropical cyclones, and thousands in floods (mostly in China), earthquakes, and tsunamis. I have selected 10 wildfires to be discussed below. While not all of them necessarily qualify as being “major,” each has one or more aspects that make it noteworthy. • 1825 – The Great Miramichi Fire: The largest (and deadliest) wildfire in the history of Canada was the Miramichi Fire of October 7, 1825. It ranks among the three largest forest fires ever recorded in North America. An estimated 4 million acres of New Brunswick and Maine forest burned and at least 160 people died, but the toll may have been much higher since an unknown number of loggers in the area are likely to have perished. Many more died because of exposure to the elements and a lack of food. The fire left 15,000 homeless, taking out nearly all of the buildings in some towns, and wiping out roughly 20% of New Brunswick’s forests. On the evening of October 7, 1825, the firestorm, traveling at 60 miles per hour, roared through Newcastle, New Brunswick (now part of the City of Miramichi), and in less than 3 hours, 262
reduced the town of 1,000 people to ruins—of 260 original buildings, only 12 remained. To escape the blaze, many residents took refuge with livestock and wildlife in the Miramichi River. The blaze has been partly attributed to unusually hot weather in the summer and fall Great Miramichi Fire Ruins of 1825, coupled with outdoor fires of settlers and loggers. •
1871 – The Great Peshtigo Fire: The Great Peshtigo Fire was the single worst wildfire in US history in terms of fatalities. It killed an estimated 1,500 people and burned 3.8 million acres in northern Wisconsin and the Upper Peninsula of Michigan during the week of October 8-14, 1871. Twelve communities were destroyed. The blaze was sparked by railroad workers clearing land for new tracks during extremely dry summer weather. On the day of the fire, a cold front moved in from the west, bringing strong winds that fanned the fires out of control and escalated them to massive proportions. When the forest fires came sweeping into Peshtigo, there was no advance warning. Winds may have been over 100 miles per hour. The heat melted objects that indicate the fire’s temperature was over 2000° F. The flames were over 200 feet tall. Every building in town was built of wood, the bridges were wood, and the roads were paved with sawdust. A firestorm ensued. The fire jumped across the Peshtigo River and burned on both sides of the inlet 263
town. Survivors reported that the firestorm generated a fire whirl that threw rail cars and housHunkering Down During the es into the air. Great Peshtigo Fire Many escaped the flames by immersing themselves in the Peshtigo River, wells, or other nearby bodies of water. Some people drowned, some succumbed to hypothermia in the frigid river, and it is also claimed that still others died when the fire caused some of the waters to boil. Coincidentally, the Peshtigo Fire happened the same night as the Great Chicago Fire of 1871; however, because Peshtigo lost its only telegraph line in the blaze, survivors had no way to notify the government or outside newspapers. While the nation quickly learned of the Chicago fire— which killed about 300 people and destroyed thousands of buildings—the horror of what happened in Peshtigo went totally unheard of for days. The combination of wind, topography, and ignition sources that created the firestorm at the boundaries of human settlement and natural areas is known as the “Peshtigo Paradigm.” This condition was closely studied by the American and British military during World War II to learn how to recreate firestorm conditions for bombing campaigns against cities in Germany and Japan. The bombing of Dresden and the even more severe one of Tokyo by incendiary devices resulted in death tolls comparable to the atomic bombings of Hiroshima and Nagasaki. 264
•
1881 – The Great Thumb Fire: The Great Thumb Fire occurred on September 5, 1881, in the “Thumb” area of Michigan’s Lower Peninsula. The fire, which burned over 1 million acres in less than a day, was the consequence of drought, hurricane-force winds, heat, the after-effects of the Port Huron Fire of 1871, and the ecological damage wrought by the era’s logging techniques. On Monday, September 5, the town of Bad Axe in Huron County burst into flames, and high winds spread the fire to neighboring counties. The fire continued to spread through Tuesday and Wednesday, September 6 and 7, consuming most of Huron, Tuscola, Sanilac and Lapeer counties. All told, 282 people were killed in the Great Thumb Fire. The fire sent so much soot and ash up into the atmosphere that sunlight was partially obscured at many Building Burning in the Great locations on the Thumb Fire East Coast of the United States. In New England cities, the sky appeared yellow and projected a strange luminosity onto buildings and vegetation. Twilight appeared at noon on Tuesday, September 6, a day that became known as “Yellow Tuesday” due to the ominous nature of this atmospheric event. This was the first official disaster relief operation undertaken by the American Red Cross, which had been founded by Clara Barton that year. The Red Cross provided money, clothes, 265
and household items to survivors. The fire caused more than 14,000 people to be dependent on public aid. It also destroyed over 2,000 barns, dwellings, and schools. •
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1894 – The Great Hinckley Fire: The Great Hinckley Fire was a conflagration in the pine forests of Minnesota in September 1894, which burned an area of at least 250,000 acres including the town of Hinckley. The official death count was 418; the actual number of fatalities was likely higher. After a 2-month summer drought, combined with very high temperatures, several small fires started in the pine forests of Pine County, Minnesota. Saturday, September 1, 1894, began as another oppressively hot day, with small fires surrounding Hinkley and two major fires that were burning about 5 miles to the south. The situation was exacerbated by the temperature inversion that day, which added to the heat, smoke, and gases, holding them down with a huge layer of cool air. The two major fires joined together to make one large fire with flames that broke through the inversion to the high-altitude cool air. That air came rushing down into the fires to create a fire whirl, which then began to move quickly, growing larger and larger, and finally turning into a fierce firestorm. The fire first destroyed the towns of Mission Creek and Brook Park before coming into the town of Hinckley. When Ruins from the Great Hinckley Fire it was over, the
firestorm had completely destroyed six towns, and more than 400 square miles of forest lay black and smoldering. The firestorm was so devastating that it destroyed everything in its path although it lasted only 4 hours. The temperature rose to at least 2,000 °F. Barrels of nails melted into single masses, and in the yards of the Eastern Minnesota Railroad, the wheels of the cars fused with the rails. Some residents escaped by climbing into wells, ponds, or the Grindstone River. Others clambered aboard two crowded trains that pulled out of the threatened town minutes ahead of the fire. While the official number of fatalities was 418, an unknown number of Native Americans and backcountry dwellers were also killed in the fire; bodies continued to be found years later. Along with the 1918 Cloquet Fire (in which 453 were killed), it is one of the deadliest natural disasters in Minnesota history. •
1910 – The Great Fire of 1910: The Great Fire of 1910 was the worst wildfire in western US history and the second largest in the United States after the 1871 Great Peshtigo Fire. This massive forest fire burned some 3 million acres in Idaho and Montana beginning on August 20–21, 1910. It killed at least 87 people, mostly ill-equipped firefighters, including a crew of 28 who were all overcome by the flames near Setzer Creek outside Avery, Idaho. It destroyed several small towns, the worst-hit of which was Wallace, Idaho, where one-third of the town was razed. The fire was the culmination of a hot, dry summer that spawned a number of small fires, which combined into a single huge conflagration as a result of near-hurricane-force winds during the passage 267
of a strong cold front. Smoke from the fire was observed as far east as upstate New York. The fire was finally Smoldering Remnants – extinguished The Great Fire of 1910 when another cold front bringing steady rain moved in. The Great Fire of 1910 united and shaped the US Forest Service, which at the time was a newly established department on the verge of cancellation. Before the epic conflagration, there were many debates about the best way to handle forest fires—whether to let them burn because they were a part of nature and were expensive to fight, or to fight them in order to protect the forests. It was decided at the time that the Forest Service should prevent and battle every wildfire. More recently, this absolutist attitude to wildfires has been criticized for altering the natural disturbance mechanisms that drive forest ecosystem structure, which paradoxically increases the destructive potential of forest fires. •
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1918 – The Cloquet Fire: The Cloquet Fire was a massive fire that occurred in northern Minnesota in October 1918. It was the worst natural disaster in Minnesota history in terms of the number of casualties in a single day. In total, 453 people died and 52,000 people were injured or displaced, 38 communities were destroyed, and 250,000 acres of forest were burned. High winds caused a fastmoving fire that raced through the town of Cloquet, and passenger trains employed to evacuate the residents narrowly missed being set afire as
they hastily departed the area. The fire could not be contained, and it quickly spread throughout much of northern Minnesota. Early reports of the fires led to rumors that they had been intentionally started by wartime “enemy agents,” but these rumors were shown to be false, and it was determined that the cause was sparks from Ruins from the Cloquet Fire railroad trains exacerbated by drought conditions, high winds, and a lack of firefighting equipment. •
1919 – The Great Fire of 1919: The Great Fire of 1919 was a massive conflagration that began on May 19, 1919, in western Canada, 120 miles northeast of the city of Edmonton. Low snowfall in the winter of 1919 gave way to an early spring drought that dried out grass and timber. Then, in May, the area experienced hot, dry winds that desiccated the surrounding region and created a tinder-dry powder keg. This was not just one fire but a complex of fires burning on the same day. Exacerbated by rapidly shifting, incredibly high winds and large quantities of wood that had been cut for the timber industry, the quick-burning flames caused the dry boreal forest to blow up. The fire spread so fast, it could not be outrun, and with no possible evacuation, residents sought safety by immersing themselves in nearby lakes.
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In Big River, piles of cut wood worth hundreds of thousands of dollars were in the path of the flames. In an instant, 1,000 lumber workers became firefighters, and the flames were stopped 200 yards from the complex. Nearby, hundreds of Aboriginal men, settlers, forest rangers, and all able-bodied help Smoke from the Great Fire of 1919 formed crews to beat back fires wherever and however they could. There was tragedy, too. In one instance, a group of 23 Cree were camping at Sekip Lake when the fire overran them in a matter of minutes. Eleven died, including a father whose quick action saved his wife and children. The 12 who survived carried the scars from their burns for the rest of their lives. The fire, which burned 5 million acres and caused hundreds of people to lose their homes, was one of the largest in North American history. •
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1939 – The Black Friday Bushfires: The Black Friday Bushfires, which burned 4,942,000 acres and killed 71 people in Australia’s Victoria State on January 13, 1939, was the nation’s deadliest wild fire event and its worst natural disaster up to that time. About 75% of the entire state of Victoria was affected, several towns were obliterated, and well over 1,000 structures were burned and destroyed. Ash from the fires fell in New Zealand some 2,000 miles to the east. As is usually the case, the fires broke out after several months of very hot and dry weather. Also, as is usually the case, the source of ignition was attributed
to human carelessness. Then, on Friday, January 13, a strong northerly wind hit the state, causing several of the fires to combine into Flames in Black Friday Wildfire one massive front. The flames were quenched by rainstorms on January 15. Considered in terms of both loss of property and loss of life, the 1939 fires were among the worst disasters, and certainly among the worst bushfire events in Australian history. Only the subsequent Ash Wednesday bushfires in 1983 and the Black Saturday bushfires in 2009 have resulted in more deaths—75 and 173, respectively. In terms of the total area burned, the Black Friday fires are the second largest, burning 4.9 million acres, with the Black Thursday Fires of 1851 having burned an estimated 12 million acres. •
1950 – The Chinchaga Fire: The Chinchaga Fire was a forest fire that burned in the watershed of the Chinchaga River in northern British Columbia and Alberta during the summer and early fall of 1950. The area was experiencing drought conditions, and the source of ignition was attributed to human activity. At the time, the Alberta forestry department’s policy was to respond only to fires within 10 miles of settlements and major roads, so no fire suppression efforts were made, and it was allowed to burn freely. The fire alternated between “runs” of rapid spread and high intensity, interspersed 271
with periods of low activity. A series of weather systems over the summer allowed a buildup of heat and dry air, reducing the moisture levels in the forest fuels. The breakdowns of these systems produced the high northeasterly winds that drove the “runs.” The fire Flames in Chinchaga Fire was finally extinguished by cooler weather and rain in late October. The Chinchaga fire produced large amounts of smoke, creating the “1950 Great Smoke Pall,” which was first recorded on September 24 and observed across eastern North America and Europe as blue suns and moons. As the existence of the massive fire was not well-publicized, and the smoke was mostly in the upper atmosphere and could not be smelled, there was much speculation about the atmospheric haze and its provenance. Explanations included nuclear Armageddon, local fires, secret US military experiments, a US atomic blast, a solar eclipse, supernatural forces, and alien invasion. With a final size of 4,200,000 acres, Chinchaga is perhaps the largest single fire recorded in North American history. No known deaths occurred as a result of the fire. •
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2009 – The Black Saturday Bushfires: The Black Saturday Fire of February 7 – March 14, 2009, was Australia’s deadliest wildfire, and the nation’s worst natural disaster. A swarm of fires
burned 1.1 million acres, killed 180 people, and injured 414 more. Many victims died in their automobiles trying to outrun the flames. Across the state of Victoria, more than 3,500 structures burned. The fires commenced on a day when several localities across the state, including Melbourne, recorded their highest temperatures since recordkeeping began in 1859. By mid-morning on February 7, hot northwesterly winds in excess of 62 miles per Fleeing the Black hour hit the state, Saturday Bushfires accompanied by extremely high temperatures and extremely low humidity (2%); a total fire ban was declared for the entire state of Victoria. Around midday, as wind speeds were reaching their peak (78 miles per hour), a power line was ripped down, sparking a bushfire that would become the deadliest and most intense firestorm ever experienced in Australia’s post-1788 history. The overwhelming majority of fire activity occurred that afternoon and evening, fanned by the strong winds. As many as 400 individual fires were recorded on the first day. The causes of the various blazes ranged from fallen power lines to arson, but a major drought, a sweltering heatwave, and strong winds combined to create the “perfect storm” for fires. •
2018 – The 2018 California Wildfires: These fires first erupted in July of 2018, mostly in the northern part of the state, and continued burning 273
into December. The 2018 wildfire season is the deadliest and most destructive wildfire season on record in California, with a total of 8,527 fires burning an area of 1,893,913 acres and causing 104 deaths. Estimates of damages have yet to be finalized, but indications are that they will be well in excess of $15 billion. On August 4, a national disaster was declared in Northern California. The Mendocino Complex Fire, which began on July 27 and burned a total of 459,123 acres, was the largest recorded fire complex in California history. Its two major 2018 California Wildfires wildfires were the River Fire and Ranch Fire, with the Ranch Fire being California’s single-largest recorded wildfire, having alone burned 410,203 acres. In November, strong winds aggravated conditions in another round of large, destructive fires that occurred across the state. This new batch of wildfires included the Camp Fire, which burned an area of 153,336 acres, killed at least 86 people, and destroyed 18,804 structures, becoming both California’s deadliest and most destructive wildfire on record. In January of 2019, utility owner PG&E Corp filed for bankruptcy protection in anticipation of more than $7 billion in liabilities related to the Camp Fire, which is believed to have started when a PG&E power line came in contact with nearby trees. 274
Chapter 25
Future Wildfires The 2017 fire season in British Columbia set a record as the worst in recorded history, with 3,004,930 acres burned as of December 5, 2017. As of September 8, 2018, long before the end of the 2018 fire season, that record had already been broken, with 3,287,930 acres having been burned. Five of British Columbia’s 10 worst fire seasons have occurred since 2010. Similarly, California’s 2017 fire season set a record as the worst in its recorded history, with 1,381,405 acres burned. The fires destroyed or damaged more than 10,000 structures in the state, more than the previous 9 years combined, and caused 47 fatalities (almost as many as in the previous 10 years combined). As of October 3, 2018, this acreage record was broken when the total of burned acres reached 1,508,815. To date, 14 people have been killed by the 2018 fires. Increased public awareness of wildfires is not due only to increased news coverage, but the fact that more acres are burning. Wildfires in the western United States have been increasing in frequency and duration since the mid-1980s. When compared to the period between 1970 and 1986, between 1986 and 2003 wildfires occurred 275
nearly four times as often, burned more than six times the land area, and lasted almost five times as long. In the cool and wet forests of the Pacific Northwest, large fires have increased by 1,000 percent; in the Northern Rockies and Southwest, they have increased by 889 percent and 462, respectively. Nine of the 10 largest wildfires since 1960 have all occurred since 2000. Since 1895, there has been a trend of increasing temperatures at night, which doesn’t allow fuels to cool off and recover. This can lead to fires of longer duration and more smoke production, and in the last couple of decades, this trend has accelerated dramatically. During today’s hotter and drier time period, which began at the start of the 21st century, there has been a reduction of tree regeneration; forests are no longer bouncing back from fires as they did in the past. The percentage of sites where the same density of trees that had existed before the blaze grew back fell by nearly half—from 70 percent before 2000 to 46 percent after. In some places, the trees don’t come back at all, making those forests likely to disappear altogether. Researchers project that moist, forested areas are the ones most likely to face the greatest threats from wildfires, as conditions in those areas become drier and hotter. Surprisingly, some dry grasslands may be less at risk for catching fire because the intense aridity is likely to prevent these grasses from growing at all, leaving these areas so barren that they are likely to lack the fodder necessary for wildfires to start and spread. These changes reverberate beyond simply the appearance of the forest. They spell possible changes to animal habitats, for instance, and even the climate. With large-scale transitions from forest to grasslands or shrub lands, there will be a loss in the potential ability of the Earth’s vegetation to sequester carbon, and that could exacerbate climate change. 276
Natural cycles, human activities like land-use change and fire exclusion, and human-caused climate change can all influence the likelihood of wildfires. It is noteworthy that many of the areas that have seen increased wildfire activity, like Yosemite National Park and the Northern Rockies, are protected from or were relatively unaffected by human land-use change, thus suggesting that climate change is the major factor driving the increase in wildfires in these places. Since 1970, the average temperature in the West has increased by 3.5o F, and the fire season has lengthened by 78 days. Higher spring and summer temperatures and earlier spring snowmelt typically cause soils to be drier for longer, increasing the likelihood of drought and a longer wildfire season. These hot, dry conditions also increase the likelihood that wildfires will be more intense and longer-burning once they have been ignited by lightning or human activity. Though the current trend of increasing severe wildfire frequency in parts of the US is projected to continue as the climate warms, droughts and wildfires are not equally likely to occur every year. Natural, cyclical weather occurrences such as El Niño events will impact the likelihood of wildfires by affecting levels of precipitation and moisture, thus leading to year-byyear variability in the potential for drought and wildfires regionally. On balance, however, because temperatures and precipitation levels are projected to change further over the course of the 21st century, the overall potential for wildfires in the western United States is projected to continue increasing. The nature of climate change is continuing to unfold, and there probably won’t be a new “normal” in our lifetimes. In recent years, the cost of wildfires has spiraled out of control. Data on total US property damage from wildfires are hard to come by, but the costs are estimated 277
to be on the order of hundreds of millions of dollars per year. The fires that ravaged Northern California wine country in 2017 caused at least $3.3 billion in insured losses. In addition to property damage, wildfires cost states and the federal government millions in firesuppression management. The US Forest Service’s yearly fire-suppression costs have exceeded $1 billion for 13 of the 18 years from 2000 to the present. In 2015, these costs exceeded $2 billion, and in 2017 they totaled almost $3 billion. During the height of the Central California Soberanes Fire in 2016, the United States Forest Service estimated it was costing about $8 million per day to fight the wildfire. By the time the blaze was fully contained at 132,000 acres, firefighting costs were the highest in US history, totaling more than $206 million. The Soberanes Fire wasn’t even one of the 10 largest on record in California, but the high price tag is one of the signs that the US is losing the battle against wildfires. Fighting fires now accounts for over half of the Forest Service’s budget; two decades ago, it represented only about 16 percent. The environmental and health costs of wildfires are also considerable. Not only do wildfires threaten lives directly, but they also have the potential to increase local air pollution, exacerbating lung diseases and causing breathing difficulties even in healthy individuals. Longer fires seasons with larger and more frequent outbreaks have strained firefighting resources beyond their limits. Of particular concern are the effects on the firefighters themselves. Firefighters can experience physical and mental fatigue during a wildland fire due to strenuous work activity, high altitudes, long and irregular work shifts, lack of sleep, improper nutrition, and unpredictable and stressful events. Fatigue and stress can increase the risk of injury, accidents, and worsened 278
health. Studies have shown that working 12 hours or more per day is associated with a 37% increased risk of injury.
Fighting a Wildfire
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Section VI
Killing Her Slowly Pollution and the Earth’s Demise
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Introduction Since its beginning, the Earth’s environment has been subject to destabilizing challenges. Originally, those challenges were natural in origin—such things as asteroid and comet impacts, earthquakes, and volcanoes. Beginning a few hundred years ago, however, humans have added additional challenges—especially in densely populated areas—with manmade pollution such as feces and urine, trash, and smoke. In relatively recent times, people have been introducing into the environment such things as toxic chemicals, heavy metals, plastics, and radioactive contamination. Humans have already significantly degraded the life-sustaining capabilities of the Earth’s air, land, and water, and one must wonder how long this can go on before one or more of those components becomes no longer viable. The magnitude and breadth of the problem is such that it cannot be resolved by individuals, by companies, by groups, or even by specific nations; it requires worldwide international cooperation, a dynamic that is exceptionally difficult to achieve. In this book, both energy pollution (noise, light, thermal, and visual) and chemical substance pollution of the air, land, and water are discussed. Also discussed is environmentalism and the efforts that are being made 283
to minimize pollution. Quite frankly, the subject makes for depressing reading and the reader may feel that the situation is hopeless—that there is nothing s/he can do to make a difference. Well, that’s not entirely correct. Below are listed a number of actions an individual can take and, while the contributions of 1 person may indeed be negligible, if 1 million, 10 million, or 100 million people were to follow these recommendations, the collective impact could be substantial. Ways an individual can help reduce pollution:
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Use environmentally safe products;
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Recycle used motor oil and filters;
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Compost yard trimmings;
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Report illegal dumping;
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Pick up after pets;
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Dispose of trash properly;
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Use water-based paints;
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Recycle everything possible;
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Take unsafe special materials to a designated disposal center;
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Don’t litter;
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Wash your car on the lawn, not in the driveway.
Chapter 26
Pollution in General Pollution is the introduction into the natural environment of contaminants that cause adverse change. Historically, we humans have regarded the air, water, and land that surround us as waste receptacles and have given little consideration to the ecological consequences of our actions. Pollutants—the components of pollution— can be either chemical substances or energies.† These substances can be either foreign to the environment or naturally occurring. Chemical substances can be simple substances (e.g., lead, arsenic, mercury), chemical compounds (e.g., carbon dioxide, methane, sulfur dioxide), or alloys (e.g., steel, brass, bronze). Chemical substances can exist as solids, liquids, gases, or plasma, and may change between these phases of matter with changes in temperature or pressure. Also of considerable concern is radioactive contamination, which can accompany all three types of chemical substance pollution. Forms of potential energy pollution—such as light, heat, and noise—are not matter, and are thus not †
Curiously, most common pollutants seem to have names that begin with the letter “P”, to wit population, pee, poop, plastics, pharmaceuticals, pesticides, petrol, power equipment, particulates, power plants, plutonium, phosphates, power lines, photons, and paint.
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considered to be “substances.” According to Popular Science, pollution killed 9 million people in the world in 2015, Pollution unquestionably kills people—lots of them—as well as millions upon millions of animals, and there are those who suggest that it is killing the Earth itself. While in theory it would be extremely difficult to truly destroy this planet, there are indications that we are making it a place that doesn’t support human life. We have already significantly degraded the life-sustaining capabilities of the Earth’s air, land, and water, and one can only wonder how long this can go on before one or more of those components becomes no longer viable. The Gaia hypothesis, formulated by James Lovelock and Lynn Margulis in the 1970s, proposes that living organisms interact with their inorganic surroundings on Earth to form a synergistic, complex system that helps to maintain and perpetuate the conditions necessary for life on the planet. This hypothesis considers all lifeforms to be part of one single living planetary being called Gaia—the Earth being seen as a self-regulating system involving the biosphere, the atmosphere, the hydrosphere, and the pedosphere—all tightly coupled as a unitary evolving system. The hypothesis contends that this system as a whole seeks to create a physical and chemical environment optimal for contemporary life. Many processes in the Earth’s surface essential for the conditions of life depend on the interaction of living forms, especially microorganisms, with inorganic elements, thus establishing a global control system that regulates Earth’s surface temperature, atmosphere composition, and ocean salinity. Humans, and their polluting activities are disrupting these systems and making the Earth “sick.” With respect to Gaia, then, humans are much like the influenza virus that makes 286
humans sick. Our increasing presence is getting things so out of whack that, in the manner of a human immune system, the planet has no choice but to respond by attacking. Many believe that there is nothing humans can do to reverse the process. For example, the planet is simply too overpopulated to halt its own destruction by greenhouse gases, and, in order to survive, mankind must start preparing now for life on a radically changed planet.1†† When people think of pollution, chemical substance pollution of the air, land, and water are the types that most readily come to mind. • Air pollution is the contamination of air by particulate matter and harmful gases, mainly oxides of carbon, sulfur, and nitrogen. Some examples of air pollution causes are: exhaust fumes from vehicles; the burning of fossil fuels, such as coal, oil, or gas; heavy industry; harmful off-gassing from substances such as paint, plastic production, etc.; and radiation spills or nuclear accidents. •
††
Land pollution is the degradation of the Earth’s soil caused by a misuse of resources and improper disposal of waste. Some examples of land pollution are: heavy metals; radiation spills or nuclear accidents; inland oil spills; illegal dumping; litter (especially plastics); pesticides, herbicides, fungicides, and other
Gaia’s “arsenal of weapons” includes viruses, and the relatively new H5N1 influenza virus is the most lethal of these. It is good at killing, having a mortality rate in excess of 50%, but it is not yet good at spreading. If it mutates to the point of becoming as contagious as the H1N1 influenza strain of 1918, it could then rival the ferocity of some strains of Ebola, and be as contagious as the common cold. In a worst-case scenario, that would mean that 2 billion people, 26% of the world’s population, would die. For more information on the influenza virus, please see my 2015 book, The Deadliest Pandemic.
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farming chemicals; and damage and debris from unsustainable mining and logging practices. •
Water pollution is the contamination of any body of water (lakes, groundwater, oceans, etc.). Some examples of water pollution are: raw sewage dumping and runoff; runoff of pesticides, herbicides, fungicides, and other farm chemicals; illegal dumping of substances or other matter; industrial waste spills; radiation spills or nuclear accidents; and biological contamination, such as bacteria growth.
Radioactive contamination may be a component in each of the three types of pollution. It may occur due to release of radioactive gases, liquids, or particles, which are deposited on surfaces or within solids, liquids, or gases, where their presence is unintended or undesirable. Such contamination presents a hazard because of the radioactive decay of the contaminants, which emit harmful ionizing radiation such as alpha or beta particles, gamma rays, or neutrons. Contaminants can remain lethally radioactive for hundreds of thousands of years. Radioactive contamination can result from the improper handling or disposal of radioactive medical or industrial products, nuclear reactor accidents, or fallout from nuclear weapons tests. It also inevitably results from certain processes, such as the release of radioactive xenon in nuclear fuel reprocessing. Moreover, a variety of radionuclides occur naturally in the environment. They are sometimes brought to the surface or concentrated by human activities like mining, oil and gas extraction, and coal consumption. The most toxic non-radioactive threats associated with pollutants are: lead, mercury, chromium, pesticides, 288
and cadmium. These and other anthropogenic toxins are discharged into the environment primarily by the most polluting industries which are: • Lead-Acid Battery Recycling: lead. •
Mining and Ore Processing: mercury, lead, cadmium, and naturally radioactive materials.
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Lead Smelting: lead.
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Tannery Operations: aldehydes.
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Artisanal Gold Mining: mercury, lead, cyanide.
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Landfills: methane, carbon dioxide, toxic metals, ammonia, toxic organic compounds and pathogens.
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Industrial Parks: lead.
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Chemical Manufacturing: arsenic, cadmium, cyanide, mercury, chromium, lead, pesticides, volatile organic compounds.
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Product Manufacturing: lead, chromium, cadmium, arsenic, cyanide, dioxins, mercury, sulfur dioxide, volatile organic compounds and other particulates.
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Dye Industry: sulfuric acid, chromium, copper.
chromium,
tannins,
The most polluted places in the world and the causes for their pollution include: • Chernobyl, Ukraine – Nuclear reactor meltdown. •
Lake Karachay, Russia – Nuclear weapons waste disposal.
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Fukushima, Japan – Nuclear reactor meltdown.
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Dzerzhinsk, Russia – Chemical weapons waste.
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Kabwe, Zambia– Lead and zinc mining. 289
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La Oroya, Peru – Lead smelting.
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Mailuu-Suu, Kyrgyzstan – Radioactive mining waste.
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Norilsk, Russia – Heavy metals smelting.
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Sukinda, India – Chromite ore mining.
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Sumgayit, Azerbaijan – Industrial and agricultural chemical production.
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Tianying, China – Lead production.
While not garnering anywhere near as much public attention as chemical substance pollution, energy pollution is nevertheless seriously problematic. There are four types of energy pollution: noise, light, thermal, and visual. • Noise pollution is any loud sounds that are either harmful or annoying to humans and animals. Some examples of noise pollution are: transportation (motor vehicles, aircraft, helicopters, trains); construction or demolition activities; portable equipment such as used by homeowners for property care; military sonar; and human activities such as sporting events, concerts, or rowdy play. •
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Light pollution is the unwanted presence of artificial light. Some examples of light pollution are: street lamps that shine light in all directions, instead of just downward; lighting that is left on when not needed for visibility; over-illumination; light trespass, which involves unwanted light impinging on one’s property; glare that leads to unsafe driving condition; light clutter (excessive groupings of lights) that may generate confusion, distract from obstacles, and potentially cause
accidents; and skyglow, which is the brightening of the night sky over inhabited areas. •
Thermal pollution is the change of air or water temperature caused by human activity. Some examples of thermal pollution are: release of warmed water coolant by power plants and manufacturers; urban runoff during warm weather of water heated by passing over hot pavement; and rapid release of cold water from reservoirs into warmer streams.
•
Visual pollution (not really a type of energy pollution, nor is it a type of chemical substance pollution, but this is a convenient place to locate it) is a subjective aesthetic issue having to do with anything visual that interferes with one’s ability to view an attractive scene. Some examples of visual pollution are: tall buildings that block an attractive view; billboards, signs, trash, antennas, electric/telephone wires, automobiles; as well as graffiti and such.
These seven types of pollution mentioned above will each be discussed in some depth in later chapters.
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Chapter 27
Energy Pollution People generally do not pay as much attention to energy pollution as they do to substance pollution, probably because reports concerning it are less dramatically and widely covered. Nevertheless, it is very much of a problem. There are four types of energy pollution: noise, light, thermal, and visual. In this writing, I have chosen to cover energy pollution before substance pollution because it is less complex and easier to understand.
Noise Pollution Noise pollution, as previously stated, describes loud sounds that are either harmful or annoying to humans and animals. Some examples of noise pollution are: transportation (motor vehicles, aircraft, helicopters, trains); construction or demolition activities; portable equipment such as is used by homeowners for property care; military sonar; and human activities such as sporting events, concerts, or rowdy play.
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Noise is frequently described as ‘unwanted sound’, and, within that context, it is generally present in some form in all areas of human, animal, or environmental activity. The dominant source of noise pollution is motor vehicle traffic, which produces about 90% of all unwanted noise. Levels of highway traffic noise typically range from 70 to 80 decibels at a distance of 50 feet from the roadway. These levels are high enough to affect a majority of people, interrupting concentration, increasing heart rates, or limiting the ability to carry on a conversation. The sound generated by a conversation between two people standing 3 feet apart is usually in the range of 60–65 decibels. Most people like the sound level in their homes to be in the 40–45 decibel range. The noise level in a crowded restaurant is the range of 80–90 decibels, and at a band concert, it is about 120 decibels. While motor vehicle traffic is responsible for the highest quantity of environmental noise, the decibel level of jet airplanes when taking off or landing is much higher. That can be in the earsplitting 120–150 decibel range, high enough to cause physical pain. Sound only becomes physically painful at about 125 decibels, but prolonged exposure to a level of 85 decibels is enough to cause hearing loss. It is therefore Aircraft Noise Pollution possible to be exposed to volumes that are damaging without even being aware of it. In addition to causing hearing loss, noise pollution can cause hypertension, high stress levels, tinnitus, sleep disturbances, and other harmful effects. 293
Noise can have a detrimental effect on a number of wild animals, increasing the risk of death by changing the delicate balance in predator or prey detection and avoidance, and interfering with the use of sound in communication—especially in relation to reproduction and navigation. Illustratively, noise pollution is believed to have caused the death of certain species of whales that beached themselves after being exposed to the loud sound of military sonar. The deafening noise of gas and oil explorations are so loud that they cause devastating effects to sea life in the local area. Extreme noise pollution has been known to kill hundreds of dolphins and whales at a time, many of which are already on the brink of extinction. Sociologically, sound can be an expression of power by humans— especially young males with low socioeconomic status—who attempt to use noise (e.g., loud automobiles, loud motorcycles, and loud music) to dominate the soundscape with their particular sound. In the bar business, establishments with high volumes of noise seem to be considered “happening places” and, as such, have a special draw for the younger crowd, but presumably not for the older. Studies have shown that people spend less time drinking in bars that don’t play music than in bars that do. But it’s not just the presence or absence of music that matters; it’s the volume and tempo as well. People drink faster and order more drinks when the music is faster and/or louder. There are two likely causes for this: (1) higher levels of arousal; and (2) because of the noise levels, people give up trying to communicate with each other and drink instead of talking.
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Light Pollution Light pollution, as previously stated, is the unwanted presence of artificial light. Some examples of light pollution are: street lamps that shine light in all directions, instead of just downward; lighting that is left on when not needed for vision; over-illumination; light trespass, which involves unwanted light impinging on one’s property; glare that leads to unsafe driving conditions; light clutter (excessive Light Pollution groupings of lights) that may generate confusion, distract from obstacles, and potentially cause accidents; and skyglow, which is the brightening of the night sky over inhabited areas. Light pollution refers to multiple problems—all of which are caused by inefficient, unappealing, or (arguably) unnecessary use of artificial light. Moreover, light pollution results in secondary air, land, and water pollution, because the greater the amount of light that is used, the greater is the demand for electricity, which places an additional load on polluting power plants. Medical research suggests that a variety of adverse human health effects may be caused by light pollution. Health consequences may include: sleep disruption, increased headache incidence, worker fatigue, medically defined stress, decrease in sexual function, and increase in anxiety. The effects of light at night on animals can be highly variable—beneficial, neutral, or detrimental—depending on the amount of light and the species involved. On balance, however, its presence disturbs ecosystems. Light 295
pollution poses a serious threat in particular to nocturnal wildlife, having negative consequences for plant and animal physiology. It can confuse animal navigation, alter competitive interactions, change predator-prey relations, and cause physiological harm.
Thermal Pollution Thermal pollution, as previously stated, is the change of air or water temperature caused by human activity. Some examples of thermal pollution are: release of warmed water coolant by power plants and manufacturers; urban runoff during warm weather of water heated by passing over hot pavement; and rapid release of cold water from reservoirs into warmer streams. The primary problematic type of thermal pollution is the increase of water temperatures caused by human activities. The most common of these activities is the use of water as a coolant by power plants, oil refineries, and industries. When water used as a coolant is returned to the natural environment at an increased temperature, the rapid change in temperature decreases oxygen supply, changes metabolic rates, and affects ecosystem composition. Even small temperature changes may result in deadly thermal shock to aquatic life, cause reproduction difficulties and lower disease resistance. Heated water from these sources may be controlled by the use of: • cooling ponds, which are man-made bodies of water designed for cooling by evaporation, convection, and radiation; •
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cooling towers which transfer waste heat to the atmosphere through evaporation and/or heat transfer;
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cogeneration, a process in which waste heat is recycled for domestic and/or industrial heating purposes.
Many are familiar with the sight of hyperboloid cooling towers, which can be very large (up to 600 feet tall and 300 feet in diameter) and are highly visible. Hyperboloid Cooling Towers They are often associated with nuclear power plants, although they are also used in a few coal-fired plants, and to some extent, in various large chemical and other industrial facilities.
Visual Pollution Visual pollution, as previously stated, is neither a type of energy nor a type of chemical substance pollution, but rather a subjective aesthetic issue having to do with anything visual that interferes with one’s ability to view an attractive scene. Some examples of visual pollution are: tall buildings that Sign Pollution block sightlines; billboards; signs; trash; antennas; electric/telephone wires; and abandoned automobiles; as well as graffiti and such. While in the broad sense of the term, atmospheric haze and smog could qualify as “visual pollution” because they interfere with the ability to view distant objects, they are more appropriately considered to be 297
air pollution. More narrowly defined, visual pollution is visual blight of the sorts delineated above. Visual stimuli from the external world cause changes in the viewer’s mental state, and those changes can be either positive or negative depending on the mind-set of the viewer. For example, a well-placed billboard may be a thing of beauty to advertisers, but to the traveler whose view of the rolling hills or the rustic village is obstructed, it is visual pollution. Graffiti is a unique element in this issue in that its sole purpose is one of altering visual stimuli. Because of subjective aesthetics, however, the end result may be considered by some as art, or it may be considered by others as an eyesore.
Graffiti – Art or Eyesore?
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Chapter 28
Air Pollution Air pollution, as previously stated, is the contamination of air by particulate matter and harmful gases, mainly oxides of carbon, sulfur, and nitrogen. Some examples of air pollution causes are: exhaust fumes from vehicles; the burning of Air Pollution fossil fuels, such as coal, oil, or gas; heavy industry; harmful off-gassing from substances such as paint, plastic production, etc.; and radiation spills or nuclear accidents. Polluting substances can be solid particles, liquid droplets, or gases. Particulate matter is generally very fine dust, only a few micrometers in size. Common gaseous pollutants include carbon monoxide, sulfur dioxide, chlorofluorocarbons (CFCs), and nitrogen oxides produced by industry and motor vehicles. Photochemical ozone and smog are created when nitrogen oxides and hydrocarbons react to sunlight.
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Carbon dioxide (CO2), because of its role as a greenhouse gas in global warming, has been described as “the leading pollutant” and “the worst climate pollution.”
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Sulfur dioxide (SO2) is generated by the combustion of coal and petroleum. Further oxidation of SO2, usually in the presence of a catalyst such as NO2, forms H2SO4, and thus acid rain.
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Nitrogen oxides (NOx), particularly nitrogen dioxide (NO2), are expelled from high-temperature combustion.
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Carbon monoxide (CO) is a product of combustion of fuels such as natural gas, coal, or wood.
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Ammonia (NH3), which is emitted from agricultural processes, although in wide use, is both caustic and hazardous.
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Volatile organic compounds are categorized as either methane (CH4) or non-methane (NMVOCs). Methane is an extremely efficient greenhouse gas that contributes significantly to global warming.†
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Chlorofluorocarbons (CFCs), which are particularly harmful to the ozone layer, were emitted from products that are currently banned from use.
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Particulates, which can be generated by human activities, such as the burning of fossil fuels, are linked to health hazards such as heart disease, altered lung function, and lung cancer.
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Radioactive contamination comes from sources such as: nuclear power generation; nuclear explosions; and nuclear weapons research, manu-
It is amusing to note that not too many years ago, bovine flatulence was considered to be the primary air pollutant in the state of Vermont.
facture, and deployment. It also results from natural processes such as the radioactive decay of radon. Motor vehicle emissions are one of the leading causes of air pollution. Primary among the anthropogenic stationary pollution sources are: fossil fuel power plants; oil refineries; petrochemical plants; heavy manufacturing industries—especially lead smelting, chemical plants, PVC and other plastics factories, and metal-production factories; large agricultural operations, which produce ammonia and methane; landfills, which release methane and carbon dioxide; radioactive contamination from sources such as nuclear power generation and nuclear weapons research, manufacture, and deployment; and military operations, which can be responsible for radiation, toxic gases, and rocket-fuel pollutants. Natural causes of air pollution include volcanoes (ash, sulfur dioxide, and hydrogen chloride); wildfires (smoke and carbon monoxide); dust storms; methane from animal flatulence; and radon gas from radioactive decay within the Earth’s crust. There are available a number of air pollution control devices that work to prevent a variety of different pollutants—both gaseous and solid—from entering the atmosphere primarily out of industrial smokestacks. These control devices can be separated into two broad categories: devices that control the amount of particulate matter escaping into the environment, and devices that control acidic gas emissions. They can either destroy contaminants or remove them from an exhaust stream before it is emitted into the atmosphere. Particulate collectors, including electrostatic precipitators, are designed to remove high-volume dust loads from an airstream. Scrubber systems (e.g., chemical scrubbers, gas scrubbers, 301
particulate scrubbers) can also be used to remove some particulates, but their primary forte has to do with removing chemicals and/or gases from industrial exhaust streams. Traditionally, the term “scrubber” has referred to pollution control devices that use liquid to wash unwanted pollutants from a gas stream. Recently, the term has also been used to describe systems that inject a dry reagent or slurry into a dirty exhaust stream to “wash out” acid gases. Air pollution has both acute and chronic effects on human health, affecting a number of different systems and organs. These effects range from minor upper respiratory irritation to more serious conditions including: chronic respiratory and heart disease; lung cancer; acute respiratory infections in children; and chronic bronchitis in adults. Air pollution can also aggravate pre-existing heart and lung disease or prompt asthmatic attacks. In addition, short- and long-term exposures have also been linked with premature mortality and reduced life expectancy. According to a World Health Organization report, air pollution in 2012 caused the deaths of around 7 million people worldwide. Among the cities worldwide with the highest levels of air pollution are: Zabol, Iran; Ahvaz, Iran; Gwalior, India; Allahabad, India; Norilsk, Russia; Riyadh, Saudi Arabia; Patna, India; Raipur India; Delhi, India; Lucknow, India; and Peshawar, Pakistan. Air pollution has been a diverse, ongoing problem worldwide and is, in fact, receiving considerable scientific, political, media, and public attention. Over the years, there have been a number of specific acute incidents that have been particularly destructive. Three of these are profiled below. The first of these, the eruption of Mount Tambora, while not anthropogenic, is included to illustrate the enormous impact that a single particu302
late-matter air-pollution event can have on the environment and humans. • On April 10, 1815, Mount Tambora, an Indonesian volcano, underwent an eruption that rated a 7 (or “super-colossal”) on the Volcanic Explosivity Index, the second-highest level on the index and the largest eruption in the world in more than 1,600 years. Estimates Mount Tambora are that in the vicinity of the eruption, 11,000 people died from direct volcanic effects and another 49,000 died from post-eruption famine and epidemic diseases. The eruption hurled millions of tons of dust, ash, and sulfur dioxide into the atmosphere. The larger particles fell to the ground shortly after being ejected, but the finer particles circled the Earth, resulting in a “volcanic winter,” with average global temperatures decreasing significantly. The year 1816 became known as the “Year Without a Summer.” In much of the northern hemisphere, crops failed and livestock died, resulting in the worst famine of the 19th century. As a consequence, more than 65,000 people died in Europe and North America. • The Great Smog of London was a severe airpollution event that affected the British capital from December 5 to December 9, 1952, and then dispersed quickly when the weather changed. On December 4, an anticyclone settled over a windless London, causing a temperature inversion 303
with cold, stagnant air trapped under a layer of warm air. The resultant fog, mixed with (mostly coal) smoke from home and industrial chimneys, fumes from motor vehicle exhausts, and other pollutants such as sulfur dioxide, formed a persistent smog, and blanketed the city the following day. Although London was accustomed to heavy fogs, this one was denser and longerlasting than any previous fog. Visibility was reduced to a few yards, Great Smog of London making driving difficult or impossible; apart from the London Underground, public transport ceased to operate, and suspension of the ambulance service forced the public to transport themselves to hospitals. Outdoor sports events were cancelled, and smog was so dense that it even seeped indoors, resulting in cancellation of concerts and film screenings as visibility decreased in large enclosed spaces, and stages and screens became difficult to see from the seats. Government medical reports at the time estimated that as of December 8, 4,000 people had died as a direct result of the smog, and 100,000 more were made ill by the smog’s effects on the human respiratory tract. More recent research suggests that the total number of fatalities was considerably greater, with at least 6,000 more dying in the following months as a result of the event. 304
•
The Bhopal disaster was a gas leak incident on the night of December 2–3, 1984, at the Union Carbide pesticide plant in Bhopal, India. As of 2010, it was considered to be the world’s worst industrial disaster. Official estimates were that the leaked gases killed at least 3,787 people and injured between 150,000 and 600,000. Others estimate that 8,000 died within 2 weeks, and another 8,000 or more have since died from gas-related diseases. Bhopal Disaster Girl The factory was built in 1969 to produce the pesticide Sevin, using methyl isocyanate (MIC) as an intermediate. In late October 1984, the storage tank E610 containing 42 tons of MIC lost the ability to maintain its pressure. MIC production was halted, and parts of the plant were shut down for maintenance. Maintenance included the shutdown of the plant’s flare tower so that a corroded pipe could be repaired. With the flare tower still out of service, production of Sevin was resumed in late November, using MIC stored in two other tanks still in service. As of early December 1984, most of the plant’s MIC-related safety systems were malfunctioning and many valves and lines were in poor condition. In addition, several vent gas scrubbers had been out of service, as was the steam boiler used to clean the pipes. During the late evening hours of December 2, water was believed to have en305
tered Tank E610 while attempts were being made to unclog it. The introduction of water into the tank subsequently resulted in a runaway exothermic reaction, which was accelerated by contaminants, high ambient temperatures, and various other factors. The pressure in the tank increased fivefold, but refinery employees assumed the reading was caused by instrumentation malfunction. The reaction in the tank reached a critical state at an alarming speed, with both temperature and pressure increasing far beyond design levels. One employee witnessed a concrete slab above the tank crack as the emergency relief valve burst open, and pressure in the tank continued to rise even after atmospheric venting of toxic MIC gas had begun. Direct atmospheric venting should have been prevented or at least partially mitigated by at least three safety devices, which, it turned out were malfunctioning, not in use, insufficiently sized, or otherwise rendered inoperable. About 40 tons of MIC escaped from the tank into the atmosphere within 2 hours. An employee triggered the plant’s alarm system, but the external alarm had been disconnected from the internal alarm, so those downwind from the site were not alerted, while the workers evacuated the plant and traveled upwind. The initial effects of exposure were coughing, severe eye irritation, a feeling of suffocation, burning in the respiratory tract, blepharospasm, breathlessness, stomach pains, and vomiting. The health care system immediately became overloaded, and thousands of people had died by the following morning. The primary causes of deaths were choking, reflexogenic circulatory collapse, and pulmonary edema. 306
Chapter 29
Land Pollution Land pollution, as previously stated, is the degradation of the Earth’s soil caused by a misuse of resources and improper disposal of waste. Some examples of land pollution are: heavy metals; radiation spills or nuclear accidents; inland oil spills; illegal dumping; litter Land Pollution (especially plastics); pesticides, herbicides, fungicides, and other farming chemicals; and damage and debris from unsustainable mining and logging practices. Lead heads the list of heavy-metal toxic threats from pollution. Its primary anthropogenic sources are lead smelting and improper disposal of waste, with additional sources being manufacturing, mining, and ore processing. The lead-smelting industry generates wastes in the form of toxic wastewater, solid waste, and volatile compounds like sulfur dioxide that are released into the air.
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Worldwide, nearly 6 million tons of lead are used annually, with about 4 million tons of that being employed in lead-acid batteries that are primarily utilized in vehicles. Europe and the US have tightly regulated recycling infrastructures for lead, but in developing countries, hundreds of thousands of informal recyclers collect used lead-acid batteries Used Lead-Acid Battery Casings and either take them to small-scale factories, where they are crudely smelted, or simply break them up themselves. Although lead poisoning is one of the oldest known work and environmental hazards, today’s understanding of the small amount of lead necessary to cause harm did not come about until the latter half of the 20th century. There is no known amount of lead that is too small to cause the body harm. Long-term exposure to even the tiniest amounts of these compounds can cause brain and kidney damage, hearing impairment, and learning problems in children. Excessive amounts of lead in the blood can damage the digestive, nervous, and reproductive systems, and cause stomach aches, anemia, and convulsions. Industrial mining and ore processing can cause land pollution problems including erosion, formation of sinkholes, loss of biodiversity, and contamination of soil, groundwater, Industrial Mining and surface water by 308
chemicals from mining processes. Extreme examples of pollution from mining activities include coal seam fires such as those at Burning Mountain in Australia and the Centralia Mine Fire in Pennsylvania; they can last for years or even decades, causing massive amounts of environmental damage. Ore mills generate large amounts of waste tailings. For example, 99 tons of waste are generated per ton of copper extracted, and extraction of a ton of gold results in 200,000 tons of tailings. These tailings can be toxic, containing mercury, lead, cadmium, and naturally radioactive materials, and they can also leach into groundwater and nearby streams and rivers. Artisanal gold mining is the small-scale independent mining of gold by individuals and small groups of people. The digging and sluicing involved in artisanal mining can result in water siltation, erosion, and soil degradation, spreading harmful materials, such as lead, which are located within the soil. Mercury and other dangerous chemicals, such as cyanide, are commonly used in artisanal gold mining. Since such mines are almost always set up near rivers, excess chemicals are often distributed directly into waterways. Although this informal industry accounts for only 20% of the global gold production, it is the single biggest cause of mercury pollution in the world. Landfills can pollute their local environment by contaminating the soil or leaching pollutants into groundwater or aquifers. Every day, the average person produces 4.4 pounds of waste, of which 2.3 pounds ends up in landfills. The United States, with less than 5% of the world’s Landfill Maintenance 309
population, produces approximately 30% of world’s total waste. Much of the pollution problem results from the wide variety of refuse accepted, especially illegally discarded substances, or from pre-1970 landfills that may have been subject to little control in the US or EU. In some places, efforts are made to capture and treat leachate from landfills before it reaches groundwater aquifers. However, landfill liners always have a finite lifespan, though it may be 100 years or more, and, eventually, every liner will leak, allowing pollutants to contaminate groundwater. A large portion of landfill waste contains biodegradable organic matter from households, businesses, and industry. As this material decomposes, it releases a variety of toxic gases, mainly methane and carbon dioxide. In some locations, the gases are captured and the methane is burned to produce electricity. Litter—i.e., waste products that have been disposed of improperly, without consent, at inappropriate locations—usually involves items such as aluminum cans, cardboard boxes, or plastic bottles, which people discard without apparent regard for their disposal. Litter can remain visible for extended periods of time before it eventually biodegrades, with some items made of condensed glass, Styrofoam, or plastic possibly remaining in the Everyday Litter environment for over a million years. Cigarette butts are the most littered item in the world, with 4.5 trillion discarded annually. Estimates on the amount of time required for cigarette butts to break down vary, ranging from 5 years to 400 years 310
for complete degradation. Large and hazardous items of rubbish—such as tires, electrical appliances, electronics, batteries, and large industrial containers—are sometimes dumped in isolated locations, such as national forests and other public land. Young people from 12 to 24 years of age cause more litter than those of other age groups, and 78% of litterers are male. Of people who regularly cause litter, only 18% are 50 years of age or older, and that percentage is less than 5% in New England. While 75% of Americans admit to littering in the last 5 years, 99% of the same individuals claim that they valued a clean environment. The presence of litter invites more littering. Agricultural endeavors are unusual in that they involve pollutants being intentionally introduced into the environment by humans. While the use of such things as insecticides, herbicides, fungicides, and fertilizers are good for crops, they are bad for the environment. They persist and accumulate in the soil, mix with water, and ultimately contaminate groundwater and Pesticide Spraying streams as well as the soil itself, often reaching levels that are toxic to humans and other animals. While the hazards of “-cides” are rather obvious (“-cide,” is derived from the original Latin term “-cida,” meaning “a thing that kills”), the risks of fertilizers are more subtle. Fertilizers contain three primary plant nutrients: mainly nitrogen and phosphorous, with smaller amounts of potassium. The first two are the most important as pollutants. Only a fraction of the nitrogen-based fertilizers is converted to produce and other plant matter. 311
The remainder accumulates in the soil or is carried into groundwater and streams as nitrate pollution. Synthetic fertilizers are not alone in creating this problem, because animal manures also contain high levels of nitrogen and phosphorus. Farm animals in the US produce huge quantities of manure—about 130 times more feces than the country’s human population. Moreover, livestock “emissions” (notably bovine flatulence) are responsible for 18% of greenhouse gases (as compared to 14% for motor vehicles). Radioactive land contamination is most likely to result from the improper handling or disposal of radioactive medical or industrial products, nuclear reactor accidents, or fallout from nuclear weapons tests. The foremost example of a “major nuclear accident” is one in which a reactor core is damaged and significant amounts of radioactive isotopes are released Hazardous Radioactive Waste into the environment. Examples of this include the Kyshtym Disaster (1957), the Three Mile Island Disaster (1979), the Chernobyl Disaster (1986), and the Fukushima Daiichi Disaster (2011). About 60% of all nuclear-related accidents have occurred in the US. Listed below, by cause, are some of the places in the world with the worst land pollution: • Radioactive Contamination: Fukushima, Japan; Chernobyl Ukraine; The Polygon, Kazakhstan; Hanford Nuclear Site, US; Siberian Chemical Combine, Russia; Mailuu-Suu, Kyrgyzstan; Sellafield, UK; Mayak, Russia; Mailuu-Suu, Kyrgyzstan. 312
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Heavy Metal Smelting: Tianying, China; La Oroya, Peru; Norilsk, Russia.
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Chemical Production: Sumgayit, Azerbaijan; Dzerzhinsk, Russia.
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Mining Operations: Kabwe, Zambia; Sukinda, India.
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Miscellaneous: Agbogbloshie, Ghana (electronic waste disposal); Kalimantan, Indonesia (agricultural pollution); Niger River Delta, Nigeria (petroleum operations).
As is the case with most types of pollution, serious pollution of the land generally develops over an extended period of time. Sometimes, however, shortduration major disasters can occur. Not surprisingly, the most frequently occurring disasters are those involving radioactive contamination. Among the noteworthy land pollution disasters have been: • The Chernobyl disaster was a catastrophic nuclear accident that occurred on April 25–26, 1986 at the Chernobyl Nuclear Power Plant near the nowabandoned town of Pripyat, in northern Ukraine, USSR, approximately 65 miles north of Kiev. The Chernobyl accident is considered the most disastrous nuclear power plant accident Chernobyl Disaster in history, both in terms of cost and casualties. Official reports indicate that in the immediate aftermath of the accident, 237 people suffered from acute radiation sickness and among them, 31 died within the first 3 months. 313
Thirty-six hours after the accident, Soviet officials enacted a 6-mile exclusion zone around the facility, which resulted in the rapid evacuation of 49,000 people, primarily from Pripyat, the nearest large population center. The evacuation zone was expanded from 6 to 18 miles about 1 week after the accident, and a further 68,000 persons were evacuated, including from the town of Chernobyl itself. Approximately 40,000 square miles of land was significantly contaminated with fallout, with the worst-hit regions being in Belarus, Ukraine, and Russia. The total number of permanently resettled people nearly tripled to 350,000 between 1986 and 2000 in an action that is regarded as largely political in nature, with the majority of the rest evacuated in an effort to redeem lost trust in the government. Estimates of the number of deaths that will eventually result from the accident vary enormously. Disparities reflect the lack of solid scientific data, differing assumptions, differing methodologies, and, of course, differing politics. Both the World Health Organization and the United Nations’ Chernobyl Forum predict that the eventual death toll could reach 4,000. The private Union of Concerned Scientists predicts that the number of excess cancer deaths will be approximately 27,000, while the activist organization Greenpeace claims that, in Belarus, Russia, and Ukraine, the accident could already have resulted in 10,000–200,000 additional deaths in the period between 1990 and 2004. •
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The Fukushima Daiichi disaster was a catastrophic nuclear accident that occurred on March 11, 2011, at the Fukushima Daiichi
Nuclear Power Plant in Ōkuma, Fukushima Prefecture, Japan. It was classified as a Level 7 event on the International Nuclear Event Scale, the only nuclear accident other than Chernobyl in 1986 to be so classified. It was initiated by the magnitude-9 Tohoku earthquake and subsequent tsunami, the epicenter of which was located approximately 45 miles east of the Oshika Peninsula of Tōhoku, Japan. When the earthquake struck, Reactors 1, 2, and 3 were in operation, but units 4, 5, and 6 were off-line for a scheduled inspection and refueling. The operating reactors immediately automatically shut down their sustained fission reactions. As a result, the plant stopped generating electricity and could no longer use its own power to run equipment. One of the two connections to offsite power also failed, so 13 on-site emergency diesel generators began providing power. When the gigantic tsunami struck 50 minutes after the initial earthquake, it overwhelmed the plant’s 33-foot-high seawall and flooded the low-lying rooms in which the emergency diesel generators were housed. The generators failed, resulting in a loss of power to the critical coolant water pumps. The secondary emergency pumps, which were run by batteries, kicked in, but after 24 hours, they ran out of power and the reactors began to overheat. A number of hydrogen-air Fukushima Daiichi Reactor Fire 315
chemical explosions occurred between March 12 and March 15; in each case, the explosions occurred at the top of the units in their upper secondary containment buildings. In addition to the hydrogen-air explosions, the insufficient cooling led to three nuclear meltdowns, and the release of radioactive material. The government initially ordered a staged evacuation and, on March 12, an estimated 50,000 people were evacuated; the number increased to 170,000–200,000 on March 13, 2011. In July of 2013, it was revealed that the plant continued to leak radioactive water into the Pacific Ocean. There are no clear plans for decommissioning the facility, but the plant’s management estimates that it will take 30 to 40 years. Meanwhile, in July 2016, they revealed that groundwater continues to flow in and mix with the highly radioactive water inside the wrecked reactor buildings, and they state that they are technically incapable of preventing this. To date, there have been no fatalities linked to short-term radiation exposure as result of the disaster. Predicted future cancer deaths due to accumulated radiation exposures in the population living near Fukushima have ranged in the academic literature from none to several hundred. •
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The Kyshtym disaster was a catastrophic nuclear accident that occurred on September 29, 1957, at the Mayak facility, in the eastern Urals area of the Soviet Union, a production site for nuclear weapons plutonium, and a nuclear-fuel reprocessing plant. The incident was classified as a Level 6 disaster on the International Nuclear
Event Scale (INES) making it the third-mostserious nuclear accident ever recorded, behind only the 2011 Fukushima Daiichi disaster and the 1986 Chernobyl disaster, both of which were classified as Level 7 on the INES. The Mayak plant was built between 1945 and 1948 in a great hurry and in total secrecy, as part of the Soviet Union’s atomic bomb project, and many safety and environmental precautions were ignored. Among other things, the nearby Lake Karachay was used as a dumping ground for large quantities Mayak Nuclear Facility of high-level radioactive waste too “hot” to store in the facility’s underground concrete storage vats. The original plan was to use the lake as a place to temporarily store the highly radioactive material until it could be returned to the plant’s vats, but this proved impossible due to the lethal levels of radioactivity. Today, Lake Karachay is said to be the most polluted place on the planet. The disaster was the result of the underground vats exploding due to a faulty cooling system. The resulting radioactive cloud, which contained 50–100 tons of high-level radioactive waste, contaminated an area of more than 290 square miles, resulting in 200+ fatalities and exposing about 270,000 people to dangerous radiation levels. The Soviet regime kept this accident 317
secret for almost 30 years. Between 1958 and 1991, more than 30 small communities in the region were removed from Soviet maps. As of 2017, Mayak is still active, and it serves as a reprocessing site for spent nuclear fuel. •
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The Kuwaiti oil fires, which occurred in January and February of 1991, were the result of Iraqi military forces setting fire to approximately 650 oil wells and a number of other low-lying oilfilled terrain features as part of a scorched-earth policy while retreating from Kuwait in response to the advances of Coalition military forces in the Persian Gulf War. Initially, the fires burned out of control because land mines and other warfare conditions prevented firefighting crews from being sent in. During the uncontrolled burning phase from February to April, the ignited wellheads burned through between 4 and 6 million barrels of crude oil, and between 2.5 and 3.5 billion cubic feet of natural gas per day. The toTank and Kuwaiti Oil Fires tal amount of oil burned is generally estimated at about one billion barrels. Eventually, privately contracted crews extinguished the fires, capping the last well on November 6, 1991, at a total cost of $1.5 billion (1991 USD; $2.78 billion 2018 USD) to Kuwait. Also, as part of its military strategy, in an attempt to foil a potential amphibious landing by US Marines, Iraq opened the outflows of some 46 oil rigs and pipelines into the Persian Gulf, releasing
5–10 million barrels of oil before the last gusher was capped in late October, 1991. The fires have been linked with what was later called “Gulf War Syndrome,” a chronic disorder afflicting military veterans and civilian workers; it includes fatigue, muscle pain, and cognitive problems,. Studies have indicated, however, that the firemen who capped the wells did not report any of the symptoms that the soldiers experienced. The causes of Gulf War Syndrome have yet to be been determined. Although scenarios predicting long-lasting environmental problems with global atmospheric gas levels due to the burning oil sources did not transpire, ground-level oil spills have impacted negatively on the environment regionally for an extended period of time.
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Chapter 30
Water Pollution Water pollution, as previously stated, is the contamination of any body of water (lakes, groundwater, oceans, etc.). Some examples of water pollution are: raw sewage dumping and runoff; runoff of pesticides, herbicides, fungicides, and other farm chemicals; illegal dumping of substances Industrial Wastewater Pollution or other matter; industrial waste spills; radiation spills, or nuclear accidents; and biological contamination, such as bacteria growth. Water pollution is caused by many of the following: discharge of commercial wastewater into surface waters; discharges of untreated domestic sewage; discharges of chemical contaminants (such as chlorine) from treated sewage; release of waste and contaminants into urban runoff flowing to surface waters; agricultural runoff— which may contain chemical fertilizers and pesticides; leaching from land pollution; and littering. Water 321
pollution causes approximately 14,000 deaths per day, mostly due to contamination of drinking water by untreated sewage in developing countries. In urban areas of developed countries, industries and automobiles release into the air large amounts of toxic metals that eventually settle onto the ground. During rainstorms, these pollutants are carried by “storm water runoff” into a local sewer system or directly into a nearby body of water. Storm water runoff from urban areas— including pesticides from lawns and home gardens— is one of the most significant sources of toxic water pollution. Many of the industries that are the worst land polluters also produce significant amounts of water pollution. Among them are battery manufacturing and recycling, industrial mining and ore processing (including iron and coal), artisanal gold mining, and agriculture. Generally speaking, land pollution ultimately results in water pollution because of leaching and runoff. There are a number of industries whose primary polluting effect is on water. Among them are: • Fossil-Fuel Power Plants, particularly those that are coal-fired, are by far the worst contributor to toxic pollution of US waters. Power plants dump more pollutants—such as mercury, lead, cadmium, chromium, and arsenic—into our waters than the next nine industries combined. Coal is more often associated with billowing smokestacks than it is with water, but virtually every stage of coal’s lifecycle—from mining to processing to burning—uses enormous amount of water, to which it adds pollutants. The heavy metals in the waste discharges can cause neurological and developmental damage, as well as cancer, in humans. 322
Coal is typically washed with water and chemicals to remove impurities before it is burned, and the resulting slurry must then be stored in impoundments. When coal is burned, it leaves behind a grey powder-like substance known as coal ash. More than 100 million tons of coal ash and other waste products are produced by coal-fired power plants in the United States annually, and it, too, must be stored in impoundments, often the same ones as the slurry. In the 21st century, there have been a number of impoundment accidents that often resulted in leakage and occasionally in significant failures. The largest of these, the TVA Kingston Fossil Plant Ash/Slurry Spill, will be discussed later in this chapter. •
Tannery Operations, whether small- or largescale, use significant quantities of water and involve chemical and organic compounds that can be powerful pollutants. The two main types of tanning are chrome tanning and vegetable tanning, with chrome tanning making up a large majority of the industry. Agents such as chromium, vegetable tannins, and aldehydes, are the primary pollutants of the industry. Other materials that may also be used in the pretreatment and tanning processes include sulfuric acid, sodium chlorate, limestone, and limestone soda ash. Because there is a wide variety in the chemicals used during the tanning process, wastewater from this industry can have very different chemical makeups. However, chromium contamination and high chemical oxygen demand are the most typical problems associated with tannery effluents, both 323
of which can pose serious risks to the environment and human health.
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Chemical Manufacturing includes the production of a wide variety of chemicals: basic chemicals including pigments, dyes, gases and petrochemicals; specialty chemicals such as pharmaceutical products and essential oils; synthetic materials like plastics; paint products, cleaning products; and other chemicals including film, ink and explosives. The dye industry and pesticide industry are also part of the chemical industry. Major pollutants include arsenic, cadmium, cyanide, mercury, chromium, and lead. The specific pollutants discharged by organic chemical manufacturers vary widely, but some of the organic compounds that may be discharged are benzene, chloroform, naphthalene, phenols, toluene, and vinyl chloride. The pollutants most frequently found in the largest quantities at chemical manufacturing sites include pesticides and volatile organic compounds.
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The Dye Industry historically used natural dyes extracted from plants, minerals, or animals, but since the mid-19th century, humans have produced artificial dyes to achieve a broader range of colors and to render the dyes more stable when subjected to wear and washing. Dyes are used primarily in the production of consumer products including textiles, paints, printing inks, paper, and plastics. Many different types of dyes consisting of varied chemical compounds are used in production, depending on the type of textile or product being dyed. There are more than 3,600 different types of textiles dyes alone.
The textile industry is one of the largest industry sectors globally and produces an extraordinary 120 billion pounds of fabric annually, using up to 9 trillion gallons of water. The top pollutants from the dye industry are chromium, lead, and cadmium. Other harmful pollutants include sulfur, nitrates, chlorine compounds, arsenic, mercury, nickel and cobalt. Plastic Pollution is not a by-product of industrial processes, but rather the discarding—either intentional or unintentional—of end-use products. Worldwide, approximately 400 million tons of plastic are produced annually, and plastics make up about 10% of all discarded waste. Plastics are inexpensive and durable, so the level of their use by humans is high. But the Plastics Water Pollution chemical structure of most plastics renders them resistant to many natural processes of degradation, and they are particularly problematic as pollutants. Estimated biodegradation times are: plastic bags—20 to 100 years; disposable diapers—50 to 450 years; plastic bottles—70–450 years; monofilament fishing line—600 years; and sanitary pads—500 to 800 years. And then there is Styrofoam. Styrofoam most commonly appears in single-use products and, since it is not biodegradable, it can persist in the environment for more than a million years. Less than 18% of plastics are recycled.
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Most polluting plastics eventually end up in the world’s oceans. Much of this comes from ocean-based sources—ships, oil rigs, and such, with the largest source being discarded fishing gear, but plastics from land-based sources such as littering and landfills also ultimately find their way to the oceans as a result of wind and water runoff. Oceans are currently waste receptacles for at least 8 million tons of plastics annually. Plastics in the ocean either wash up on beaches or collect in ocean gyres (large systems of circulating ocean currents), the most notorious of which is the “North Pacific Trash Vortex.” This vortex, located halfway between Hawaii and California, is about the size of Texas and contains an estimated 90,000 tons of plastics totaling approximately 1.8 trillion pieces. Living organisms—particularly marine animals— can be harmed either by mechanical effects, such as entanglement in plastic objects or problems related to ingestion of plastic waste, or through exposure to chemicals within plastics that are toxic to marine life and to humans. The toxins that are components of plastic include diethylhexyl phthalate, which is a toxic carcinogen, as well as lead, cadmium, and mercury. Listed below, by cause (note that in most cases, raw sewage is also one of the major elements of the water pollution), are some of the places in the world with the worst water pollution: • Tannery Operations: Matanza-Riachuelo River, Argentina; Buriganga River, Bangladesh; Ganges River, India.
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Textile Industry: Marilao River, Philippines; Citarum River, Indonesia.
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Product Manufacturing: Sarno River, Italy.
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Mining and Ore Processing: Doce River, Brazil.
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Agriculture Industry: Mississippi River, USA.
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Chemical Manufacturing: Yellow River, China;
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Radioactive Contamination: Lake Karachay, Russia.
A number of short-duration acute water pollution disasters have occurred over the last half-century. The most noteworthy among these include: • The Amoco Cadiz Oil Spill occurred on March 16, 1978, when this very large crude carrier (VLCC) ran aground on Portsall Rocks, 3 miles off the coast of Brittany, France. The ship had encountered stormy weather with gale conditions and high seas while in the English Channel and, at around 9:45 AM, a heavy wave damaged the ship’s rudder, causing it to lose maneuverability. A German tug arrived at 12:20 PM to provide assistance but, because of the ship’s huge mass and Force 10 storm winds, was unable to prevent the vessel from drifting toward the shore. At 8:04 PM, the Amoco Cadiz ran aground for the first time, flooding its engines. It grounded again at 9:39 PM, this time ripping open the hull and starting the oil spill. The crew was rescued by French Naval Aviation helicopters at midnight, while the captain and one officer remained aboard until 5:00 AM Break-up of the Amoco Cadiz the next morning. At 10:00 AM on March 17, the vessel broke in two, releasing into the sea its entire cargo of 327
1.6 million barrels of crude oil as well as4,000 tons of fuel oil. A 12-mile-long oil slick was then spread onto 45 miles of the French shoreline by northwesterly winds. Eleven days later, the ship broke again because of buffeting by high storm seas. The wreckage was later completely destroyed with depth charges by the French Navy. The incident resulted in the largest loss of marine life from an oil spill ever recorded to that date. •
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The Exxon Valdez Oil Spill occurred on March 24, 1989, at 12:04 AM local time, when the VLCC oil tanker, carrying 1.2 million barrels of crude oil, ran aground on Bligh Reef in Alaska’s Prince William Sound. Chemical dispersant, a surfactant and solvent mixture, was applied by a private company on March 24 with a helicopter, but the target area was missed. Mechanical cleanup was started shortly afterwards using booms and skimmers, but the skimmers Exxon Valdez Aground were not readily available during the first 24 hours following the spill, and thick oil and kelp tended to clog the equipment. Over the next few days, 257,000 barrels of crude oil spilled into the sound, eventually covering 1,300 miles of coastline and 11,000 square miles of ocean. Immediate effects included the deaths of 100,000–250,000 seabirds, at least 2,800 sea otters, approximately 12 river otters, 300 harbor seals, 247 bald eagles, 22 orcas, and an unknown number of salmon and herring.
The incident is considered to be one of the most devastating human-caused environmental disasters. When the accident occurred, the ship’s captain, who was widely reported to have been drinking heavily that night, was asleep in his bunk, and the third mate had the con. The vessel’s Collision Avoidance System radar was not functioning. If it had been, it would have indicated an impending collision with Bligh Reef by detecting the radar reflector placed nearby. During the official investigation, it was suggested that the third mate failed to properly maneuver the vessel, possibly due to fatigue, but he blamed the helmsman for not following steering orders. Everyone blamed everyone else, and multiple lawsuits were filed that took many years to work their way through the courts. Despite the efforts of the cleanup crews, only 10% of the total oil was actually completely cleaned. As of 2010, there were still an estimated 23,000 gallons of Valdez crude oil in Alaska’s sand and soil, and it was only breaking down at a rate estimated to be less than 4% per year. •
The Baia Mare Cyanide Spill, which occurred on January 30, 2000, was one of the worst environmental disasters ever experienced in Europe. The spill was the result of a leak from a dam for gold mining tailings located near Baia Mare, Romania, and owned and operated by Aurul, a joint venture of the Australian mining company Esmeralda Exploration and the Romanian government. When the dam burst, 3,500,000 cubic feet of cyanidecontaminated water, containing an estimated 100 tons of cyanide, flooded into the Somes River. 329
After the spill, the Somes had cyanide concentrations of more than 700 times the permitted levels. The Somes flows into the Tisza, Hungary’s second largest river, which then flows into the Danube. In mid-February 2000, as the spill reached the Romanian section of the Danube, the Romanian government temporarily banned fishing and the usage of Danube water for drinking. The large volume of the Danube’s water diluted the cyanide but, in some sections, it still remained as much as 20 to 50 times the maximum permitted concentration. The spill contaminated the drinking supplies of over 2.5 million Hungarians. In addition to cyanide, heavy metals were also washed into the river and had a long-lasting negative impact on the environment. The deadly impact of the cyanide was worst in the Tisza where, in one stretch, virtually all living things died, and further south, in the Serbian section, 80% of the aquatic life was killed. As many as 100 humans were hospitalized for cyanide poisoning resulting from consuming contaminated fish. Not surprisingly, both Esmeralda Tisza River Fish Kill and the Romanian government denied responsibility, claiming that the damage of the spill has been grossly exaggerated and that the fish died in such numbers because of lack of oxygen due to the freezing of the river. The Hungarian government argued that the cold weather was not unprecedented, and 330
called the storing of cyanide adjacent to a river “madness.” •
The TVA Kingston Fossil Plant Ash Slurry Spill occurred just before 1:00 AM on December 22, 2008, when a dike for an 84-acre coal-fly ash slurry pond ruptured at the Tennessee Valley Authority’s Kingston Fossil Plant in Roane County, Tennessee. The accident released 1.1 billion gallons of coal-fly ash slurry (a mixture of a coal combustion byproduct and water); it was the largest fly ash release in United States history. The plant had received more than 7½ inches of rain during the 3 weeks prior to the accident. This rain, together with 12 °F temperatures at the time of the incident, were identified by TVA as factors that contributed to the failure of the earthen embankment. The spill covered 300 acres of surrounding land with up to 6 feet of sludge. It affected a number of homes, covering 12, pushing 1 off its foundation, rendering 3 uninhabitable, Kingston Ash Slurry Spill and damaging 42 others. Although residents feared contamination of their drinking water supply, early tests at the intake 6 miles upstream from the ash flow showed that the public water supply met drinking water standards. A later test of the river water close to the spill showed significantly elevated levels of toxic metals, including arsenic, copper, barium, cadmium, chromium, lead, mercury, nickel, and thallium. The EPA first estimated that 331
the spill would take 4 to 6 weeks to clean up, but the Southern Environmental Law Center, said the cleanup could take months and possibly years. As of 6 months after the spill, only 3% of the it had been cleaned and project costs were then estimated to be between $675 and $975 million. •
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The Deepwater Horizon Oil Spill is an industrial disaster that began on April 20, 2010, with an explosion on a British Petroleum (BP) drilling rig in the Gulf of Mexico. The explosion and subsequent fire resulted in the sinking of the Deepwater Horizon and the deaths of 11 workers; 17 others were injured. The blowout also caused a massive offshore oil spill in the Gulf of Mexico, and that is considered to be the largest accidental marine oil spill in the world and the largest environmental disaster in US history. At approximately 9:45 PM local time on April 20, high-pressure methane gas from the well expanded into the drilling riser and rose into the drilling rig, where it ignited and exploded, engulfing the platform. At the time, 126 crew members were on board. Eleven Deepwater Horizon Fire missing workers were never found despite a 3-day US Coast Guard search operation and are believed to have died in the explosion. Preliminary investigational findings indicated several serious warning signs in the hours prior to the blowout. Equipment readings showed gas bubbling into the well, which
could signal an impending blowout. Eventually, it was determined that a failed blowout preventer in the well was the cause of the methane release. The explosion was followed by a fire that engulfed the platform. After burning for more than 1 day, Deepwater Horizon sank on April 22. The oil leak was discovered on the afternoon of April 22 when a large oil slick began to spread at the former rig site. The Flow Rate Technical Group (FRTG) estimated the initial flow rate was 62,000 barrels per day. Two remotely operated underwater vehicles were unsuccessfully sent down to attempt to cap the well. By June, 143 human spill-exposure cases had been reported to the Louisiana Department of Health and Hospitals. In July, it was reported that the spill was already having a “devastating” effect on marine life in the Gulf. A massive response ensued to protect beaches, wetlands, and estuaries from the spreading oil utilizing skimmer ships, floating booms, controlled burns, and 1.84 million gallons of oil dispersant. It is believed that the addition of dispersants made the oil more toxic. The oil flowed for 87 days, and the total estimated volume of leaked oil approximated 4.9 million barrels. After several failed efforts to contain the flow, BP declared the well sealed on September 19, 2010, but reports in early 2012 indicated that the well site was still leaking. On April 15, 2014, BP also claimed that cleanup along the coast was substantially complete, but the United States Coast Guard responded by stating that a lot of work remained. Everyone blamed everyone else and, by May 26, more than 130 lawsuits relating to the 333
spill had been filed against one or more of BP, Transocean, Cameron International Corporation, and Halliburton Energy Services.. In November 2012, as a result of actions initiated by the US Department of Justice, BP settled federal criminal charges by pleading guilty to 11 counts of manslaughter, 2 misdemeanors, and 1 felony count of lying to Congress. BP agreed to a thenrecord-setting $4.525 billion in fines and other payments. As of February 2013, criminal and civil settlements and payments to a trust fund had cost the company $42.2 billion. In July 2015, BP agreed to pay $18.7 billion in fines, the largest corporate settlement in US history. The spill had an enormous economic impact on BP and also on the Gulf Coast’s economy sectors such as offshore drilling, fishing, and tourism. One study projects that the overall impact of lost or degraded commercial, recreational, and mariculture fisheries in the Gulf could be $8.7 billion by 2020, with a potential loss of 22,000 jobs over the same time frame.
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Chapter 31
Environmentalism Modern technologies have provided a variety of methodologies for the prevention, or at least minimalization, of pollution, but the use of them can be costly. Even low-technology approaches— implementing water and energy conservation practices, using environmentally benign fuel sources, using nontoxic or less toxic chemicals in processes, reusing materials rather than disposing of them as waste, and protecting sensitive areas—have a price tag. So, while there are a number of “ways” to minimize pollution, it appears that “will” to implement them is in short supply. Poor countries and small businesses simply can’t afford pollution-control improvements, while rich countries and large businesses want to protect their advantages and profits, and feel that they should not exclusively bear the burden for improvements. Pollution became a major issue in the United States in the early 20th century, as progressive reformers took issue with air pollution caused by coal burning, water pollution caused by bad sanitation, and street pollution caused by the 3 million horses that worked in American cities in 1900, generating large quantities of urine and manure. 335
Environmental concerns became more strongly rooted in the vast social changes that took place in the United States after World War II. Although environmentalism can be identified in earlier years, only after the war did it become a widely shared social priority. This began with outdoor recreation in the 1950s, extended into the wider field of the protection of natural environments, and then became infused with attempts to cope with air and water pollution, and, still later, with toxic chemical pollutants. In 1962, the book Silent Spring by American biologist Rachel Carson was published. It cataloged the environmental impacts of the indiscriminate spraying of DDT in the US and questioned the logic of releasing large amounts of chemicals into the environment without fully understanding their effects on human health and ecology. The book suggested that DDT and other pesticides may cause cancer and that their agricultural use was a threat to wildlife, particularly birds. For example, the bald eagle, peregrine falcon, and brown pelican all nearly became extinct before scientists realized that the synthetic chemical DDT was the cause of devastating reproductive failure Dead Bald Eagle in these species. The resulting public concern led to the creation of the United States Environmental Protection Agency in 1970, which banned the agricultural use of DDT in the US in 1972. With this new concern about the environment came concern about problems such as air pollution and petroleum spills, and environmental interest grew. 336
Pollution began to draw major public attention in the United States between the mid-1950s and early 1970s, when Congress passed the Noise Control Act, the Clean Air Act, the Clean Water Act, and the National Environmental Policy Act. Severe incidents of pollution served to increase consciousness. PCB dumping in the Hudson River resulted in a ban by the EPA on consumption of its fish in 1974. National news stories in the late 1970s—especially the long-term dioxin contamination at Love Canal starting in 1947 and uncontrolled dumping in Valley of the Drums—led to the Superfund legislation of 1980. In 1979, James Lovelock published the book Gaia: A new look at life on Earth, which put forth the Gaia hypothesis, which proposes that life on Earth can be understood as a single organism. This became an important part of the Deep Green ideology. Another milestone in the environmental awareness movement was the creation of an Earth Day. Earth Day was first observed in San Francisco and other cities on March 21, 1970, the first day of spring. Earth Day is now coordinated globally by the Earth Day Network and is observed in more than 175 countries every year. The UN’s first major conference on international environmental issues, the United Nations Conference on the Human Environment (also known as the Stockholm Conference), was held June 5–16, 1972. It marked a turning point in the development of international environmental politics. Around this time, mainstream environmentalism began to show force with the signing of the Endangered Species Act in 1973 and the formation of the Convention on International Trade in Endangered Species (CITES ) in 1975. Significant amendments were also enacted to the United States Clean Air Act and Clean Water Act. Growing evidence of local and global pollution and an increasingly informed public over time have 337
given rise to environmentalism and the environmental movement, which generally seeks to limit human impact on the environment. Environmentalism continues to evolve and confront new issues such as global warming, overpopulation, and genetic engineering. The environmental movement—a term that sometimes includes the conservation and green movements—is a diverse scientific, social, and political movement. Though the movement is represented by a range of organizations, because of the inclusion of environmentalism in the classroom curriculum, the environmental movement has a younger demographic than is common in other social movements. A “Green party” is a formally organized political party based on the principles of green politics, such as social justice, environmentalism, and nonviolence. Green parties exist in nearly 90 countries around the world, and many are members of “Global Greens.” Deep Green Resistance is a radical environmental movement that views mainstream environmental activism as being largely ineffective. They argue for a radical shift in societal structures and functions. Concern for the environment has led to the development of numerous US-based environmental groups including: The Sierra Club, the Environmental Defense Fund, the Natural Resources Defense Council, the Nature Conservancy, and the Wilderness Society. Globally oriented groups such as the World Wildlife Fund and Friends of the Earth disseminate information, participate in public hearings, lobby, initiate lawsuits, stage demonstrations, and may purchase land for preservation. Environmental Demonstration
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More radical organizations, such as Greenpeace, Earth First!, and the Earth Liberation Front, have more directly opposed actions they regard as environmentally harmful. While Greenpeace is devoted to nonviolent confrontation as a means of bearing witness to environmental wrongs and bringing issues into the public realm for debate, the underground Earth Liberation Front engages in the clandestine destruction of property, the release of caged or penned animals, and other criminal acts. Such tactics are regarded as unusual within the movement, however. On an international level, concern for the environment was the subject of a United Nations Conference on the Human Environment in Stockholm in 1972, which was attended by 114 nations. Out of this meeting came UNEP (United Nations Environment Programme) and its followup United Nations Conference on Environment and Development in 1992. Other international organizations in support of environmental policies development include the Commission for Environmental Cooperation (as part of NAFTA), the European Environment Agency (EEA), and the Intergovernmental Panel on Climate Change (IPCC) Effectively responding to global environmental issues necessitates some form of international environmental governance to achieve shared targets related to energy consumption and environmental usage. Material inequality between nations make technological solutions insufficient for climate change mitigation, and political solutions are required due to the particularities of various facets of environmental crises. Environmental change mitigation strategies can be at odds with democratic priorities of prosperity, progress, and state sovereignty, because they require a collective relationship with the environment. In recent years, a number of treaties, agreements, and accords relative to the environment 339
have been put into place. The most frequently cited of these are: • Basel Convention on the Control of Transboundary Movements of Hazardous Wastes and Their Disposal (1992) •
United Nations Framework Convention on Climate Change (1992)
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Kyoto Protocol (1997)
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Stockholm Convention on Persistent Organic Pollutants (2004)
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Paris Agreement (2016)
Today, the foremost of these are the Kyoto Protocol and the Paris Agreement. The Kyoto Protocol, which was adopted in 1997 and entering into force in 2005, extended the 1992 United Nations Framework Convention on Climate Change, which commits state parties to reduce greenhouse gas emissions, based on the scientific consensus that global warming is occurring and that it is extremely likely that human-made CO2 emissions have predominantly caused it. There are currently 192 parties (Canada withdrew effective December 2012) to the Protocol. The Protocol is based on the principle of common but differentiated responsibilities: it acknowledges that individual countries have different capabilities in combating climate change, owing to economic development, and therefore puts the obligation to reduce current emissions on developed countries on the basis that they are historically responsible for the current levels of greenhouse gases in the atmosphere. The Paris Agreement is an agreement within the United Nations Framework Convention on Climate Change that deals with greenhouse-gas-emissions mitigation, adaptation, 340
and finance, starting in the year 2020. The agreement’s language was negotiated by representatives of 196 state parties and adopted by consensus on December 12, 2015. As of July 2018, 195 UNFCCC members have signed the agreement, and 180 have become party to it. Under the Paris Agreement, each country must determine, plan, and regularly report on the contribution that it undertakes to mitigate global warming. No mechanism forces a country to set a specific target by a specific date, but each target is expected to go beyond previously set targets. The election of Donald Trump to the US Presidency dealt a severe setback to the environmental movement. This was foreshadowed by his proposal, while campaigning, that the Environmental Protection Agency be eliminated. Both Trump, and the man he originally selected to head the agency, Scott Pruit, claimed to believe that carbon dioxide is not a primary contributor to global warming. While their claims may or may not have been true, indications are that Trump’s attacks on environmentalism were motivated, at least in part, by the fact that protecting the environment had been a shining star among the accomplishments of his Democratic predecessor, Barack Obama. Moreover, in keeping with his pro-big business stance, he was clearly giving a higher priority to the profits of multinational polluters than to the health and well-being of the people. Within days of his taking office, large amounts of climate information were altered or removed from both the EPA and the Whitehouse websites. He also quickly signed executive orders approving the Keystone XL and Dakota Access pipelines, both of which had been highly controversial. Additionally, he signed an order for the EPA to revise or rescind the Clean Water Rule, overturned President Obama’s Stream Protection Rule after it has been in effect for less than 30 days, and proposed 341
a rollback of the Obama administration’s extension of federal jurisdiction over lands protected by the Clean Water Act in attempts to reduce water pollution in areas surrounding toxic-waste facilities. Moreover, Trump ordered a federal review of the Clean Power Plan, which had been put in place to reduce carbon dioxide emissions chiefly from coal-fired power plants. Its removal would effectively eliminate Obama’s efforts to curb climate change. The Trump administration also announced plans to cut back Obama’s coal emissions standards for coal-fired power plants. Shortly after his inauguration, Trump unveiled what he calls the “America First Energy Plan.” His administration claims that “America has been held back by burdensome regulations on [its] energy industry.” The America First Energy Plan makes no mention whatsoever of renewable energy and instead reflects Trump’s focus on fossil fuels On June 1, 2017, Trump announced United States withdrawal from the Paris Agreement, causing the US to become the third out of 197 nations worldwide to not sign the agreement. As of 2018, the remaining two nations signed, and the US is the only nation that has not ratified the Paris Agreement. In practice, changes in United States policy that are contrary to the Paris Agreement have already been put in place. The withdrawal was supported by several Republican lawmakers who felt that withdrawal was in line with Trump’s America First Energy Plan and goals to eliminate the environmental policies of the Obama administration. The announcement has been criticized by many national and international leaders, domestic politicians, business leaders, and academics, as well as a large majority of Americans. Numerous other steps by the Trump administration have had definitive anti-environmental consequences. These include: 342
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Calling for more drilling in national parks and in nearly all US waters, as well as opening up more federal land for energy development.
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Rewriting EPA pollution-control policies for chemicals known to be serious health risks in order to make the policies more friendly to the chemical industry.
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Rolling back regulations that required the federal government to account for climate change and sea-level rise when building infrastructure.
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Rolling back the Obama administration’s fuel efficiency and emissions standards for vehicles.
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Rescinding rules limiting mercury and air toxins from power plants, limiting water pollution from coal plants, banning the pesticide chlorpyrifos, and banning methane emissions from landfills.
It is disquieting to note that recent research has found a precipitous decline in the US public’s interest in 19 different areas of environmental concern. Americans are less likely be actively participating in an environmental movement or organization and more likely to identify as “unsympathetic” to an environmental movement than in 2000. This is likely, at least in part, a lingering factor of the Great Recession in 2008. Since 2005, the percentage of Americans agreeing that the environment should be given priority over economic growth has dropped 10 points. In contrast, those feeling that growth should be given priority “even if the environment suffers to some extent” has risen 12 percent. These numbers point to the growing complexity of environmentalism and its relationship to economics. Also disquieting is the awareness that there is more violence associated 343
with environmentalism than one might expect. In 2014, 116 environmental activists were assassinated and the number increased to 185 in 2015. More than 200 were assassinated worldwide between 2016 and early 2018.
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Index A agriculture 79, 322 Alaska 53, 55, 60, 64, 73, 74, 75, 77, 89, 126, 127, 128, 138, 147, 148, 153, 154, 165, 222, 225, 226, 227, 228, 229, 328, 329 Alpide 89, 150 Amoco Cadiz 327 Antarctic 45, 51, 55, 57 Arctic 45, 51, 62, 76, 78 asteroid 20, 21, 22, 33, 37, 39, 40, 41, 85, 99, 283 Australia 20, 29, 112, 124, 168, 224, 251, 261, 262, 270, 272, 273, 309 B Barringer Crater 15, 24 battery 163, 322 Beringia 60, 61, 64 Bhopal 305 Big Bang 11 boundary 57, 89, 90, 92, 102, 103, 106, 108, 112, 113, 117, 119, 122, 133, 144, 152, 213 British Columbia 60, 148, 227, 271, 275 C California 73, 75, 92, 114, 116, 117, 128, 133, 147, 153, 154, 156, 188, 197, 225, 226, 240, 251, 273, 274, 275, 278, 326 Cambrian explosion 50 carbon dioxide 51, 62, 66, 79, 239, 251, 255, 259, 260, 285, 289, 301, 310, 341, 342 catastrophe 55, 110 chemical 48, 96, 97, 143, 238, 283, 285, 286, 287, 290, 291, 297, 301, 316, 321, 323, 324, 325, 336, 343 Chernobyl 289, 312, 313, 314, 315, 317 Chicxulub 20, 21, 85, 99 Chile 22, 53, 84, 89, 111, 112, 124, 125, 147, 165, 223, 226
China 29, 102, 104, 105, 121, 124, 130, 142, 165, 176, 177, 178, 180, 181, 182, 183, 185, 186, 223, 262, 290, 313, 327 climate 7, 24, 45, 47, 49, 56, 61, 62, 64, 78, 79, 80, 81, 170, 240, 247, 276, 277, 300, 339, 340, 341, 342, 343 Clovis 26, 65, 66, 67 CO2 38, 50, 51, 79, 80, 300, 340 coal 188, 287, 288, 297, 299, 300, 304, 309, 322, 323, 331, 335, 342, 343 comet 21, 26, 27, 37, 52, 65, 66, 67, 283 conservation 335, 338 crater 15, 21, 22, 23, 24, 26, 28, 29, 30, 33, 67, 85, 99, 231 cyanide 289, 309, 324, 329, 330, 331 D DDT 336 Deepwater Horizon 332, 333 dike 178, 179, 192, 205, 331 disease 95, 109, 180, 182, 238, 296, 300, 302 dye 324, 325 E Earth 2, 3, 5, 7, 9, 12, 13, 14, 15, 16, 17, 18, 19, 20, 21, 22, 23, 25, 26, 27, 28, 29, 30, 31, 32, 33, 35, 37, 38, 39, 40, 41, 47, 48, 50, 51, 52, 54, 55, 56, 59, 62, 65, 66, 67, 77, 83, 84, 85, 86, 87, 88, 90, 91, 92, 95, 96, 97, 98, 99, 116, 121, 138, 139, 146, 147, 150, 151, 154, 155, 158, 170, 200, 239, 245, 251, 276, 281, 283, 286, 287, 301, 303, 307, 337, 338, 339 earthquake 21, 30, 37, 84, 85, 86, 87, 88, 93, 95, 96, 97, 98, 99, 101, 102, 104, 105, 106, 107, 108, 109, 110, 111, 112, 113, 114, 115, 116, 117, 118, 119, 120, 121, 122, 123, 124, 125, 126, 127, 128, 129, 130, 132, 133,
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134, 135, 136, 137, 138, 139, 140, 141, 142, 143, 144, 146, 147, 148, 149, 150, 151, 153, 154, 155, 156, 157, 158, 159, 160, 161, 162, 170, 174, 186, 221, 222, 223, 224, 225, 226, 227, 228, 229, 315 elastic rebound 96, 116, 158 energy 21, 24, 30, 33, 34, 37, 52, 78, 85, 86, 87, 97, 98, 99, 138, 142, 147, 159, 239, 241, 283, 285, 290, 291, 292, 297, 335, 339, 342, 343 environment 7, 16, 65, 71, 77, 215, 283, 285, 286, 288, 289, 296, 301, 303, 309, 310, 311, 312, 319, 324, 325, 330, 336, 338, 339, 341, 343 epicenter 84, 86, 96, 100, 104, 105, 106, 108, 113, 118, 124, 125, 126, 127, 128, 130, 131, 134, 136, 138, 140, 142, 144, 146, 221, 224, 315 extinction 21, 22, 26, 37, 52, 66, 68, 85, 99, 233, 294 F famine 179, 180, 182, 183, 184, 303 fire 30, 95, 96, 109, 118, 120, 123, 210, 234, 236, 245, 246, 247, 248, 249, 250, 251, 252, 253, 254, 255, 257, 258, 260, 262, 263, 264, 265, 266, 267, 268, 269, 270, 271, 272, 273, 274, 275, 276, 277, 278, 318, 332, 333 firestorm 21, 262, 263, 264, 266, 267, 273 flood 170, 171, 172, 173, 174, 175, 178, 179, 180, 181, 182, 183, 184, 185, 186, 187, 188, 189, 190, 191, 192, 193, 195, 196, 197, 198, 199, 201, 205, 208, 210, 211, 214, 215, 216, 219, 234, 235, 236, 237, 240, 241 forecast 236 fossil 50, 73, 79, 287, 299, 300, 301, 342 Fukushima 148, 227, 289, 312, 314, 315, 316, 317
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G Gaia 286, 287, 337 galaxy 11, 13 Galveston 201, 202, 206 gas 11, 12, 14, 50, 51, 95, 117, 120, 157, 161, 191, 237, 287, 288, 294, 299, 300, 301, 302, 305, 306, 318, 319, 332, 340 gigantism 67 glacier 45, 172, 174, 220, 240 global warming 38, 51, 52, 55, 56, 77, 78, 79, 80, 81, 242, 300, 338, 340, 341 Great Lakes 53, 58, 59, 77, 213 Great Smog 303, 304 greenhouse 21, 38, 50, 51, 79, 239, 287, 300, 312, 340 H Haiti 144, 145, 165, 216 Hawaii 112, 114, 124, 125, 153, 154, 155, 223, 224, 326 Himalaya 152 Holocene 5, 25, 26, 27, 45, 47, 51, 56, 57, 66 Honshu 103, 107, 113, 146 Huai River 169, 177 hurricane 173, 199, 202, 203, 204, 205, 206, 207, 208, 209, 210, 211, 212, 213, 215, 216, 217, 218, 220, 236, 241, 265, 267 Hurricane Florence 218, 219 Hurricane Harvey 149, 217 Hurricane Katrina 149, 186, 212, 214, 215 Hurricane Sandy 215, 216, 217 hypocenter 86, 138, 146 I ice 7, 14, 27, 31, 45, 47, 48, 49, 50, 51, 52, 53, 54, 55, 56, 57, 58, 59, 60, 61, 62, 64, 65, 66, 72, 73, 78, 79, 80, 129, 148, 169, 172, 183, 226, 229 India 23, 139, 141, 152, 185, 226, 290, 302, 305, 313, 326 Indian Ocean 137, 138, 139, 147, 150, 225, 226 Indonesia 137, 138, 139, 151, 165, 221, 225, 229, 313, 326
J Japan 52, 89, 103, 107, 108, 112, 113, 124, 125, 126, 146, 147, 153, 156, 160, 165, 186, 221, 223, 224, 226, 227, 264, 289, 312, 315 Johnstown 188, 195, 196 K Kingston Fossil Plant 323, 331 Krakatoa 229 Kuwait 318 Kyoto Protocol 340 Kyshtym 312, 316 L Lake Agassiz 59, 60, 61, 62, 169 landslide 108, 127, 143, 152, 172, 174, 194, 225, 228, 229, 230, 231 lead 24, 174, 237, 238, 276, 285, 288, 289, 301, 307, 308, 309, 322, 324, 325, 326, 331 lightning 41, 236, 245, 251, 277 liquefaction 94, 104, 125, 127, 132, 134, 152, 153 Lisbon 96, 108, 109, 110, 111, 116, 165 litter 248, 284, 287, 307, 311 Long Island 59, 201, 208, 209, 216 Los Angeles 132, 153, 154, 192 M magnitude 30, 31, 34, 37, 84, 85, 86, 87, 92, 93, 97, 98, 99, 100, 102, 103, 104, 106, 107, 108, 111, 113, 114, 115, 116, 118, 121, 122, 124, 126, 128, 130, 131, 133, 135, 136, 137, 140, 142, 144, 146, 147, 152, 154, 155, 156, 157, 158, 169, 172, 173, 222, 223, 224, 225, 226, 258, 283, 315 mammoth 26, 66, 68, 71, 72, 73 mastodon 68, 72, 73 Mediterranean 89, 100, 101, 150, 169, 170, 221 megafauna 26, 66, 68 megathrust 92, 103, 107, 108, 124, 126, 138, 146 megatsunami 21, 228, 231
mercury 285, 288, 289, 309, 322, 324, 325, 326, 331, 343 meteor 14, 28, 29, 31, 32, 33, 34, 228 meteorite 22, 24, 28, 29, 31, 32, 33, 37, 174, 220 meteoroid 30, 31, 32 methane 12, 50, 51, 52, 285, 289, 300, 301, 310, 332, 333, 343 Mexico 21, 66, 71, 73, 74, 85, 89, 99, 126, 131, 132, 133, 151, 160, 165, 202, 204, 212, 213, 218, 224, 332 Mid-Atlantic Ridge 89, 90, 151 mining 87, 156, 188, 288, 289, 290, 307, 308, 309, 322, 329 Mississippi River 54, 59, 188, 190, 191, 195, 197, 210, 327 Moon 17, 18, 40, 52, 62, 220 Mount St. Helens 87, 231 Mount Tambora 302, 303 N North America 26, 27, 53, 56, 59, 60, 66, 67, 68, 70, 72, 73, 75, 76, 169, 246, 262, 272, 303 nuclear 21, 39, 52, 148, 149, 156, 220, 227, 272, 287, 288, 297, 299, 300, 301, 307, 312, 313, 314, 315, 316, 317, 318, 321 P Paris Agreement 340, 341, 342 Peshtigo 262, 263, 264, 267 plastic 287, 299, 310, 325, 326 plate 88, 89, 90, 91, 92, 97, 101, 102, 103, 108, 112, 119, 144, 152, 159 Pleistocene 45, 47, 51, 55, 56, 64, 67, 69, 75, 76 power plant 313 predict 39, 55, 156, 181, 235, 314 Q Quaternary 45, 47, 50, 51, 56 R radiation 37, 38, 238, 249, 287, 288, 296, 299, 301, 307, 313, 316, 317, 321
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radioactive 148, 283, 285, 288, 289, 301, 309, 312, 313, 316, 317 rain 30, 38, 120, 171, 178, 181, 183, 189, 190, 201, 210, 211, 214, 218, 219, 233, 235, 240, 268, 272, 300, 331 Red Cross 192, 196, 238, 265 rescue 136, 141, 143, 183, 234, 236, 237 Ring of Fire 88, 89, 92, 150, 151, 152, 153 S San Andreas Fault 92, 117, 133, 154 San Francisco 96, 116, 117, 118, 132, 133, 134, 135, 153, 154, 156, 165, 337 seismic 34, 86, 87, 88, 89, 93, 96, 97, 100, 101, 106, 113, 115, 122, 127, 130, 132, 137, 138, 147, 151, 152, 155, 157, 159, 160, 225 sewage 174, 215, 237, 288, 321, 322, 326 Shaanxi 29, 102, 104, 105, 165 Siberia 64, 67 smelting 290, 301, 307 smoke 31, 33, 38, 251, 255, 258, 259, 260, 266, 272, 276, 283, 301, 304 snow 34, 52, 54, 68, 72, 129, 171, 183, 233, 240, 257 Stockholm Convention 340 Sumatra 89, 137, 138, 139, 165, 225 sun 12, 13, 14, 22, 27, 30, 31, 34, 37, 51, 52, 62, 66, 79 T Tangshan 102, 121, 130, 131, 142, 165 tannery 323 tectonic 52, 87, 88, 89, 90, 96, 116, 117, 126, 130, 141, 144, 151, 153, 156, 157, 158, 159, 224, 228 textile 324, 325 Three Mile Island 312 Tohoku 113, 146, 147, 148, 149, 165, 186, 226, 227, 228, 315 toxic 215, 259, 283, 288, 289, 301, 306, 307, 309, 310, 311, 322, 326, 331, 333, 335, 336, 342
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Trump, Donald 341, 342 tsunami 22, 86, 92, 96, 101, 103, 104, 106, 107, 108, 109, 110, 111, 112, 113, 114, 115, 119, 123, 124, 125, 126, 127, 128, 137, 138, 139, 140, 146, 147, 148, 149, 155, 170, 174, 199, 220, 221, 222, 223, 224, 225, 226, 227, 228, 230, 315 Tunguska 30, 67 V Valdivia 84, 124, 125, 126, 137, 223, 224, 225 vehicle 163, 293, 301, 304 volcano 125, 303 W warning 35, 38, 87, 115, 151, 157, 158, 160, 174, 187, 189, 235, 263, 332 waste 87, 155, 188, 285, 287, 288, 289, 290, 296, 297, 307, 309, 310, 313, 317, 321, 322, 323, 325, 326, 335, 342 weather 35, 40, 78, 136, 141, 178, 181, 194, 195, 197, 199, 202, 219, 233, 235, 236, 238, 240, 247, 249, 251, 253, 258, 263, 270, 272, 277, 291, 296, 303, 327, 330 wildfire 245, 246, 247, 249, 250, 251, 253, 257, 258, 260, 261, 262, 263, 267, 268, 272, 274, 277, 278 Y Yangtze River 177, 178, 180 Yellow River 121, 177, 181, 182, 183, 327 Younger Dryas 26, 62, 66
Other Books by David Ritchey
The H.I.S.S. of the A.S.P. (2003) The Magic of Digital Fine Art Photography (2010) 26 Card Tricks (2011) Something About Scrabble (2011) Why We Are Fascinated by Dogs (2012) A Sense of Betrayal (2012) Reviewing the Montauk Legend (2013) Presidents in the Crosshairs (2013) Understanding the Anomalously Sensitive Person (2014) 349
Descended from the Gods? (2014) Those Who Know the Wyrd (2014) Tales from the Depths (2014) On Conflict (2015) Keep the Colors Flying (2015) The Deadliest Pandemic (2015) Locked and Loaded (2015) From Aardvarks to Zyzzyvas (2016) Pyramidal Mystique (2016) The Enigma of Baalbek (2016) American Demagogues (2016) Invitations to War (2016) Enduring American Mysteries (2016) Pyramids of Fire (2016) Noteworthy UFO Cases (2017) One At A Time Or All At Once (2017) Spies Uncovered (2017) Geniuses Among Us (2017) 350
Pumped Up (2017) A Brief History of Hurricanes (2017) What Is Truth? (2018) Transportation Disasters (2018) Up to The Eaves: Major Snowstorms (2018) Everybody Loves Conspiracy Theories (2018) The Automobile: An American Cultural Icon (2018) Are We Ready for Artificial Intelligence? (2018) They Say It’s Impossible (2018) Noble New Nation (2019)
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About The Author
David Ritchey’s vocations have included: naval officer, businessman, fine art photographer, psychotherapist, researcher, and writer. His avocations have included: scuba diving, sailing, skiing, tennis, golf, gardening, woodworking, dogs, magic, bridge, and SCRABBLE™. After being educated in economics at Yale University, he served for five years as an officer in the U.S. Navy, including a year in Vietnam. Back in civilian life, he initially became a businessman, but shortly thereafter followed his true inclinations and became a fine art photographer. While immersed in the art world, he became fascinated by the psychology/neurology of creativity, and returned to school to train as a psychotherapist. During his 15 years of clinical practice, specializing in hypnotherapy, he became especially interested in the psychodynamics of those clients who reported having had transpersonal (“metaphysical”) experiences, and undertook a twelveyear project of researching and writing about such people, who he speaks of as “Anomalously Sensitive Persons.” Later, he became his daughter’s business manager at her art gallery on Cape Cod, and spent a few years involved simultaneously in the worlds of both business and art. Now “retired,” he spends his time writing about a wide range of subjects that are of special interest to him. Information about his books can be found at www.davidritchey-author.com. He currently lives in historic Bucks County, Pennsylvania. He has two grown children, Harper and Mac, and a grandson, Brendan. 352
CONFRONTING THE CONFRONTING THE EARTH’S TRIBULATIONS
Over the eons of its existence, the Earth has been subjected to a host of different tribulations including cosmic collisions, ice ages, earthquakes, floods and tsunamis, wildfires, and man-made pollution. Each of these is a very interesting subject in its own right and, when writing about them, I came to realize that when the material was restricted to just one perspective and unnecessary elaboration was eliminated, the text that remained was of insufficient length to justify its publication as a stand-alone book. On the other hand, the subjects were sufficiently different from one another that they could not appropriately be reformatted as chapters in a single book. My solution was to retain the original formatting of the six brief books I had written on different but closely-related subjects, and bind them into this single volume.
EARTH’S TRIBULATIONS
David Ritchey
DAVID RITCHEY