ni
Roberto Lucia
THE
EISARTH
TREMBLING
I’M NOT!
Everything you should know to protect yourself against earthquakes, explained and illustrated by a funny professor, Prof. Pof, and his extraordinary assistants.
e .
t i .
N O S LES
r u d
w w
w
E K A U Q EARTH
k s i
CM 51528U
EDURISK
Edition not for sale
INGV
iani Roberto Luc
THE
EISARTH
TREMBLING
I’M NOT!
E K A U EARTHQ
N O S LES
e .
r u d
w w
w
INGV
k s i
t i .
Wow!
I love to watch disaster films and so do my assistants, Trumpet and Anna. You know, the movies about earthquakes and other catastrophes. Don’t you like to watch them too?
These special effects are so good they make you think it’s really happening. They’re very realistic.
w 2
r u d
e .
w w Even too realistic!!!
t i .
Tatarataaa?
I have to confess...
k s i
What a scare! Luckily nobody got hurt but my super TV, it’s all squashed. That was a real earthquake! Just when we were having such a good time looking at a fake one! What a coincidence. But that’s what real earthquakes are like, they happen when you least expect them. And you know what? They’re no fun at all!
To find out more I decided it would be a good idea to find out more about earthquakes. Maybe if you know all about them, you’ll know what to do. I don’t want to end up like my TV set. But first let me introduce myself:
Prof. Pof inventor, scholar and genius in general
The other two are Trumpet (you can recognize him by his nose) and Anna the robot-goose. Well, are you ready to begin the earthquake lesson?
Quarrrrk...
That’s why I took a big decision.
How sidomuovono continental plates Come le zolle? move?
Well, my cracked hardboiled egg will help to explain how the earth moves.The fact is that the earth is constantly moving under our feet! Let’s pretend that the Earth is a giant hardboiled egg.To make it easier to see, I have taken the water away from the oceans.The crust that forms the continents and the ocean floor is broken into several pieces.These enormous pieces (there are eight big ones) are called continental plates. Although they don’t appear to move, very very slowly they are. Outer core
r u d
Inner core
Mantle Continental plates are layers of rock that form the continents and the ocean floors.
Crust
e .
What makes continental plates move?
Let’s cut the Earth in half. At the center, just as in a hardboiled egg, is a hard, tremendously hot core, a little bigger than the Moon. Then there is a layer called the mantle, made of dense, incandescent rock. Continental plates, with the continents and oceans, rest on this sort of play-dough. The heat causes movements in the mantle, making the continental plates move.
w w
w
Sometimes the plates move away from each other...
4
t i .
When the plates push against each other it is like a game of Indian wresting between giants. For years, centuries or millennia nothing happens, and then suddenly – crack! Something gives. Somewhere underground the rock splits, releasing a tremendous force that will arrive on the surface and make everything tremble – even us! This crash-bang-boom is called earthquake, and the splits in the rock are called faults. There are different kinds of faults, depending on how the earth has moved. Some can be hundreds of kilometers long.
k s i
A fault is a split in the rock – and a big problem for us! If it divides the crust into two parts that move away from each other it is called a normal fault.
What do the continental plates and the hair on your head have in common? Speed. The plates move from less than 1 to 15 kilometers in a year. Your hair grows at about the same speed. At this pace the continents can move for thousands of kilometers, but it takes millions of years. Maybe your hair can’t wait that long before you go back to the barber!
Who cracked my breakfast?
And they call it “terra firma”! Did you know? Ages ago there was only one great continent. Scholars have called it Pangaea, which means “a Single Earth”. The continents separated a few centimeters at a time, and today they are situated as you see them on the atlas. But they haven’t stopped moving. In a few million years they will look very different!
200 million years ago
If instead the two blocks of rock push against each other, the fault is called thrust.
65 million years ago
...and other times they move closer.
today
What a mess!
With a strike-slip fault the two blocks slide sideways, rubbing against each other.
50 million years from now
Can you recognize the different continents?
The stronger the shock, the wider are the zigzag marks left by the pen, see?
They call it a scale but …
Do you know how tall you are? Of course you do. Measuring a boy or girl is easy; all you need is a yardstick. But how can you measure an earthquake? An earthquake doesn’t have a shape like you; it is a force that makes the earth move under our feet, right? Watch my little experiment with Anna. Ready?
r u d
t i .
k s i
The marks left by the pen on the paper tell us how much energy has been released by the earthquake. In fact, earthquakes can be big, small or so-so, and each of them can be assigned an order of size according to a system invented seventy years ago by Mr. Richter. Newspapers and TV often call this system the Richter Scale, but you know what? They are making a big mistake!
What is the literal meaning of the word seismograph? • Earthquake writer. • Earthquake inventor. • Earthquake scribbler. • Earthquake autograph hound. • Earthquake weigher.
Thirty times Trumpet
Roll of paper
w Pen
Reinforced concrete base
6
w w Seismo what?!!
The instruments used to measure a real earthquake act like Anna in the experiment. Here you can see one; it’s called a seismograph. In place of Anna there is a heavy weight hanging from a wire. When an earthquake strikes everything moves, only the weight stays still where it is, even more still than Anna.The roll of paper instead moves under the pen, which marks a zigzag line on it.
The base moves
It doesn’t look like it, but this instrument was designed to show where earthquake tremors are coming from. It was invented by the Chinese many centuries before the birth of Christ. It is a bronze vase decorated with the heads of dragons and frogs. Each dragon holds a ball in its mouth, while the frogs are waiting with open mouths. Can you guess how it worked?
magnitude 1
The Richter system calculates the energy of each earthquake, and calls it magnitude. For example, an earthquake of magnitude 3 is 30 times bigger than magnitude 2 and 900 times bigger than magnitude 1.
The tremor makes a ball fall into the mouth of the frog which is sitting on the side opposite the earthquake’s epicenter. To know what an epicenter is, turn to page 9!
The weight stands still
e .
What, I’m only 10 centimeters strong?
Earthquake writer.
Just as an earthquake does, I have suddenly moved the carpet under Anna’s feet. But Anna didn’t move at all because she is heavy and tends to stay where she is. She left a mark on the carpet, though, didn’t she?. Well, that mark represents the force I have exerted to move the carpet, and it can be measured.
Let’s see if the Richter system is really a scale. Pretend that Trumpet is an earthquake (sometimes he really is). Let’s put him on the lowest step, since he is a little earthquake. To be able to go to the next step, Trumpet would have to grow no less than thirty times bigger. And then another thirty times more to go on to the next step. And so on; these are pretty strange steps! The Richter, in fact, is not really a scale but magnitude 3 a mathematical system for measuring the magnitude (the energy) of earthquakes. The worst earthquake ever experienced on the Earth reached magnitude 9.5. But if magnitude 2 you think about it, Let’s run! it must have been A magnitude 9 Trumpet is coming! really gigantic!
The most ancient one
t i .
Instruments call tell us what magnitude is, that is, the size, of an earthquake even very far away, but they can’t tell us anything about its effects on people and things. To understand these effects we have to go the place involved and observe everything that has happened and listen to what people say they have heard and seen. These observations tell us the intensity of the earthquake, and its intensity is measured by the famous Mercalli Scale for example, but there are other very similar methods such as the MCS, the MSK and the EMS-98. These are real scales: each of their 12 levels (indicated by Roman numerals) represents another step in the severity of an earthquake. (indicated by Roman numerals) represents another step in the severity of an earthquake. At the beginning the effects are very slight, but one step at a time they gradually become disastrous.
I
II
Imperceptible Earthquake recorded only by instruments.
Very slight Felt by a few people on the upper floors of buildings.
IV
V
IX
Highly destructive Half of the houses built of masonry collapse. General panic.
8
e .
w w
w
Moderate Many people feel the earthquake. Objects creak, ceiling lamps sway.
Rather strong Felt outdoors, and indoors even by people who are sleeping. Doors and windows bang, some glass panes break.
X
Ruinous Severe damage to three-quarters of the houses. Some rivers overflow.
r u d
III
Slight Felt by some people indoors as a slight trembling.
VI
Strong Slight damage to houses; little cracks in walls. Everyone feels the earthquake and is afraid.
XI
Catastrophic Bridges and almost all buildings collapse. Rail tracks are torn up, pipes burst.
k s i
Epicenter
Hypocenter
Hypo and Epi
Do volcanoes and earthquakes have anything in common? Yes, they originate along the same fractures between one continental plate and another. In the zones where many earthquakes occur there are often volcanoes, such as Etna in Sicily. In Australia, where there are few earthquakes, there is not even one volcano.
Let’s see... read vibrations... Should I be worried or not?
Alarm at Trumpetopolis!
Earthquakes originate underground. The point they “start” from is called the hypocenter. It is there that the rocks break. The epicenter instead is the point on the earth’s crust just above the hypocenter. It is on the surface that the worst damage occurs, to persons and to buildings. The intensity scale grades earthquakes according to the severity of the damage and thus indicates the intensity of the tremor at that particular place.
VII
Very strong Pieces of cornices and chimneys fall. It is hard to stay standing upright.
XII
VIII
Destructive Buildings in poor condition collapse, many others are badly damaged. Bell towers and monuments collapse.
On the whole, I’d rather not think about it!
Totally catastrophic Anything manmade is destroyed. The ground cracks open, rivers are deviated from their courses.
Trumpetopolis, where Trumpet lives, has been struck by an earthquake. The intensity was grade VI at the epicenter, and then it gradually decreased further away from it, and the effects of the earthquake became less and less severe. Write the correct Roman numeral of the intencity scale in each box.
Collapsed houses cut electricity and telephone lines
r u d
A landslide makes houses collapse
A freight train derails and dangerous chemical products escape
w w
e .
Other collapsed houses cause fires
The chemical products cause fires and explosions
w
Broken pipes pollute the river
10
t i .
k s i
A dam breaks and floods the town, making other structures collapse
The gas pipes break too, causing other fires and pollution
How many people in the world live in earthquake hazard zones? • 800 million. • 1 billion. • 2 billion.
The world on its back In ancient times people knew nothing about continental plates and faults. But they still looked for answers to the frightening question: why does the earth shake sometimes? Some people thought the world was born on the back of a giant and that earthquakes occurred when he stumbled. Others imagined even stranger causes. Here are some of their explanations. But be careful: one of them is totally invented! Which one? • The Mongols thought the Earth rested on the back of a great frog. • The Japanese blamed earthquakes on an enormous fish that wouldn’t keep still. • The Eskimos thought that a seal balanced the Earth on its nose. • The Hindus believed that the world rested on the shoulders of eight elephants. • For the Greeks it was the fault of Poseidon, god of the sea. • The Maoris believed that earthquakes were caused by Ru, the son of Mother Earth, kicking hard inside her belly. The invented theory is the Eskimos’.
A severe earthquake is like a chain reaction. It causes damage that frequently leads to other damage, just the way my assistants and I do. The stronger the shock, the more chain disasters can be expected. To explain this better I have made a model that may seem terrifying, because all kinds of awful things are happening in it. But don’t worry, these things never happen all together at the same time!
But can you guess what the most dangerous reaction of all is? It is panic, the fear that makes people lose their heads. It’s only normal to be afraid of an earthquake. But fear should not keep us from acting in the safest way. For this reason, two things are important: knowing your surroundings inside out (so you can know what to expect in the case of an earthquake) and keeping as calm as you can, Understand, Trumpet?! even in difficult situations.
2 billion.
No panic
Better keep far away
r u d
3 On the surface waves that are
Here’s what happens
low but very fast form waves can travel as fast as 4 These 800 km an hour, like a jet plane!
e .
2 Ships feel nothing strange
w
w w
1A rupture in the ocean floor or
a great underwater landslide provokes movement in the mass of water
5 Near the coast the water is shal-
lower, and the waves slow down in speed but grow in height, since they still possess the same amount of energy
k s i
t i .
When a tsunami reaches the coast: • Its speed increases. • It slows down. • It continues at the same speed.
Gigantic waves
It slows down.
A tidal wave is a liquid earthquake, made of water; a very fast, high wave that can sweep away whole villages when it hits the coast. As we have all learned from the disastrous tidal wave that recently struck the islands and coasts of the Indian Ocean, this gigantic wave is also called a tsunami, which means “wave in the bay” in Japanese. But why does the sea suddenly go crazy from one moment to the next?
If you should ever happen to be standing on a beach and see the water rapidly withdrawing for many meters, then you should run away as fast as you can. Sooner or later a massive wall of water is going to crash onto the beach! Luckily, these phenomena are extremely rare in our country. The great destructive tsunami are triggered by fractures between the Ohi, ohi... continental plates (remember?) on the floor of oceans such as the Pacific and the Indian. So it is important to have alarm systems that warn the people living in these zones in time.
the waves break on the shore they 6 When can be as high as 50 meters
Can you locate on the globe the places where these disastrous tidal waves struck? • Tidal wave of 1755 in Portugal. • Tidal wave of 2004 in Southern Asia. • Tidal wave of 1964 in Alaska. • Tidal wave of 1946 in Hawaii.
Where the risk is greatest
Remember the hardboiled egg? Yes, I mean the Earth with its shell all “broken”. Here I have drawn a picture showing the fractures that divide the continental plates. It is just along these splits that the rocks, by moving away from or approaching one another, provoke most of the earthquakes that happen. It is their fault if in certain unlucky places, such as California and Japan, earthquakes occur more often. While in Australia, which sits right in the middle of a continental plate, earthquakes are practically unheard of.
Japan and California lie along the edges of the same continental plate. Australia on the other hand is at the center of another plate, far from the edges. The arrows show the direction the continental plates are moving in.
k s i
And Europe? Europe too lies close to a fracture between two continental plates, the African plate and the Eurasian one. These two enormous pieces of shell that cover the Earth are pushing against each other, slowly but forcefully, like my two assistants when they struggle over who goes first. Remember what happens when the continental plates push each other around? Right: the rocks can break and cause an earthquake. And this earthquake, big or small as it may be, will tremble under our feet.
w
14
t i .
About how many earthquakes, big and small, do you think are recorded every year all over the world? • 400 000. • 25 000. • 1 million. • 1 400.
Which two European countries are most prone to earthquakes? • France. • Great Britain. • Greece. • Spain. • Italy. • Germany.
Italy and Greece.
Come on now, let’s not exaggerate with this demonstration!
r u d
e .
w w
You push me and I’ll push back
But does every place in Europe run the risk of a terrible earthquake? No, some zones are more dangerous and others less so, at least judging by what has happened over the last thousand years. Look at the map: Germany and France seem to be a lot luckier than Greece, Italy, Spain and Albania. Everything always depends on what is happening underground, in the push-and-pull of layers of rocks. Now you know that earthquakes don’t happen by chance. They are the result of centuries or even millennia of these mega-pushes. Experts study the earthquakes of the past to see which zones are the most hazardous. From this they can make maps of seismic hazard, which indicate what quakes the various European towns can expect.
1 million.
Squaawk!
Here I have marked the epicenter of the strongest earthquakes occurring in Europe in the last five hundred years. The larger the circle, the bigger and more destructive the earthquake. As you can see, they are concentrated mainly on the Italian Apennine mountain chains and the Greek coast: but many countries have experienced this phenomenon. I haven’t marked the smaller earthquakes, but there have been thousands of them more or less everywhere.
Remember
r u d
10 lifesaving rules
If you are at home, and your house is sturdy, don’t leave it during the earthquake tremor. Wait until it is over.
Never use an elevator. The electric power it runs on could be interrupted, trapping you inside.
16
e .
w w
Take shelter under a table. It will protect you from falling plaster, furniture or lamps.
w
If you are outdoors, move away from the walls of houses. Tiles, cornices or chimneys could fall.
You can also take shelter in a doorway in a supporting wall (that is, a thick, solid wall).
Stay far from trees, street lamps, and electric wires. They might fall on you.
Another place that is quite secure is the corner of a room between two master walls (walls that face outdoors, for example).
t i .
k s i
Why is it better not to stay in the center of a room during a tremor? Because you could be hurt by falling plaster, lamps, panes of glass or other objects.
A ceiling lamp that starts to sway for no reason is a clear signal of an earthquake tremor. Most of the time that is the end of it, and if you are not staring at the lamp you don’t even realize what’s happening. Conversely, the most serious and dangerous earthquakes can really be felt just as the scale indicates. Floors and walls tremble violently, and cracks may even appear. Everybody is terribly frightened and tries to run away. Who wouldn’t? But beware: instinct is not always good counsel.
An earthquake tremor only usually lasts a moment (although it may seem forever at the time!). That’s why it’s better to wait until it is over before leaving buildings. There is no behavior that can guarantee one hundred percent safety for all earthquakes and in all places, but these lifesaving rules can help you keep your head and avoid taking pointless risks, and can reduce damage. It is always a good idea to know how the town you live in is classified as regards seismic zones, and whether the buildings are secure. In fact, if you live in a house that is unstable, it is better to run away from it than to stay there until the earthquake is over! Talk about this with your teacher and your parents.
Who is risking the most?
Do not use stairways during a tremor. Sometimes they are the most fragile part of a house.
Mark with a cross the people you think are behaving unwisely. Do not stay on or under a bridge.
Look for a place where there is nothing above you that can fall.
Good, with your flawless behavior you deserve the Lifesaving Medal, shaped like a – well, like a Lifesaver.
What? More rules? Only a few, but very, very important. Those blockheads my assistants took weeks to learn them, but kids as smart as you are will only have to read them once.
What you will feel
w
18
e .
w w
It’s no joke, finding yourself in the middle of an earthquake, one of the big ones. Even people who don’t get hurt continue to suffer from the tremendous fright. They may be confused and disoriented, they may be tired or unable to sleep properly. But this is nothing to worry about. It’s just your organism trying to get over the bad experience. Sooner or later everything will be all right again. It’s important not to keep these things to yourself, but to talk about them with friends and relatives. Remember that they need you too!
r u d
t i .
k s i
When the tremor is over, leave the house calmly. Wear shoes to keep from hurting your feet on broken glass.
Before leaving the house, switch off the gas and electricity, for safety reasons.
Help anybody who is in trouble, but do not move badly injured people. Ask an adult to help.
Go to an open area far from unsafe buildings.
Don’t go near beaches (if it is a tidal wave risk zone), dams or industrial plants.
Don’t nose around! Follow the instructions of the emergency plan and the indications of adults and of the Civil Defense.
Using the phone is pointless. Whoever you are calling will certainly not be at home. In any case, phone only if you really have to, so as not to jam the lines.
Why should you stay far from beaches and dams after a severe earthquake? Because, even some time after the tremor, the beach could be submerged by giant waves, while the structure of a dam could suddenly break. Luckily for us, these risks are extremely rare, and limited only to certain zones.
When the tremor is over, does that mean the earthquake is over? This, I’m afraid, is impossible to know. Often there are other smaller tremors, called foreshocks. Sometimes even bigger tremors can arrive. While in doubt, you have to be very, very careful and continue to act in a calm, responsible way. That’s because the damage caused by an earthquake frequently calls for rescue, organization and a lot of work. We could Hold on, Trumpet! even say that the hardest part begins then. But nobody who has a Lifesaving Medal should lose heart, should they?
And the correct rules?
Do not use a car, to avoid hindering rescuers. Which one of us three, do you think, is behaving according to the rules and which are not?
Three is the perfect number
w w
w
Monitoring the movement of faults can help to predict possible earthquakes. Some laser systems record very small movements of the earth, even less than one millimeter! One of these systems monitors the San Andreas Fault in California, a place of violent earthquakes, day and night.
20
e .
r u d
Studying big and little earthquakes from the past is fundamental to try to predict those of the future. The computer can help, but it is extremely important to search for the written testimony left us by ancient peoples. This information can then be collected in catalogues, earthquake catalogues.
t i .
k s i
But….
For now, then, we cannot predict earthquakes. But can we know if there is going to be one soon? It may be possible in the future. Seismologists are working on the problem. They take note for example of everything that happens to rocks: changes in level, displacement, micro-earthquakes, even changes in the concentration of certain gases found underground or underwater. Each of these details can be a precursor, or if you prefer a message of bad news; of the type: get ready, a big one is coming! Hmm... don’t get mad, but I have something to tell you.
Seismologists call “precursors”: • Those signs that appear to indicate that an earthquake is coming. • Those that appear first on the site of the earthquake. • The underground gases that explode, causing earthquakes.
See and predict!
strong earthquake
minor earthquake
These zones have been struck by earthquakes in the past. According to you, in which of them is it most likely that a big earthquake will strike again? Zone C should be the most likely to have another big earthquake in the future. In fact, it has already had two of that type. But nothing is really certain when you’re talking about earthquakes!
Well, I tried. But the crystal ball isn’t working; too bad. Think of how many human lives could be saved if we could know when earthquakes are coming! The destiny of millions of people would change. Experts in earthquakes (who are called seismologists) dream of being able to predict these tremendous natural upheavals, in the way they can predict, with good certainty, whether it will rain or the sun will shine. Why not? Of course they don’t use crystal balls but sophisticated instruments, utilizing above all their knowledge of the earth and studying the earthquakes of the past.
For a correct prediction, three things have to be known: where, how big, and when. That is: where will the next earthquake happen, how big will it be, and when will it happen. Let’s take Trumpetopolis, the town Trumpet comes from, as an example. Trumpetopolis is located in the vicinity of a fault or fracture in the earth. This in the past caused some big earthquakes which registered grade X on the scale. Probably, then, there will be equally bad earthquakes in the future. We also know the dates of the earthquakes that have struck Trumpetopolis. But since earthquakes don’t work on a fixed schedule, we That’s really can’t know when too bad! the next one is coming.
Those signs that appear to indicate that an earthquake is coming.
Tell me, crystal ball... is this earthquake going to come back?
Shock-proof
You are walking in a big meadow. Suddenly the earth begins to shake violently. It isn’t pleasant, but want to know something? The seismic risk of a meadow is – zero, because, since there is nothing that can fall and break, it’s impossible to get hurt. So it isn’t really the earthquake itself that kills people. What causes so many victims is mainly the collapse of buildings, bridges and roads.
Yip
w w
When the earth trembles, houses shake too! The problem is, will they manage to survive the shock? Many houses, especially the older ones, have been built to withstand vertical weights and thrusts. But an earthquake shakes them in the horizontal sense as well. If a house has not been designed to withstand these lateral forces, then it can fall down like a castle built of playing cards, crushing its inhabitants under the rubble.
22
An earthquake shakes houses all over, horizontally too.
t i .
k s i
Don’t worry, I’m not about to collapse!
Which of these houses, do you think, is most likely to remain standing after an earthquake?
What about old houses?
Most of the houses in Italy were built before the antiseismic regulations were passed. Should we tear them down and build them again? Impossible! Also because many of them are beautiful historic buildings, and solid as well. But if they are located in seismic zones, they have to be cared for attentively to make them as safe as possible. How? By restoration, by reinforcing their structures and by continuous inspections. Of course this costs a lot, while a new antiseismic house costs only a little more than an ordinary one. But it is certainly worth it!
Which of the two? plain bedrock
(soft) alluvial plain
Pillars
Beams
The elements of a house that resist best are floors and beams (horizontal) and pillars or weight bearing walls (vertical) which are connected with one another.
After an earthquake, hospitals, military personnel, firemen, and electric power plants are of vital importance. So, buildings that house these resources are extremely important and they must be more earthquake-proof than the others.
Are the effects of an earthquake the same everywhere? Which of these two villages will be shaken the hardest? The village on plain bedrock will be less severely damaged by the earthquake. The one on the alluvial plain will suffer more damage. The effects can be very different even in places very close to one another.
Houses are often designed to withstand vertical forces only, beginning with the force of gravity.
w
Floor
r u d
pyhoo o!
e .
What happens to houses
In seismic zones (places where earthquakes are likely to occur) new houses should be built in a suitable way. That is, the constructors must respect antiseismic (anti-earthquake) regulations. These rules are very important, because they say how to design the plan of a house, what materials to use, how to build the foundations and how to connect chimneys, parapets and cornices correctly. All this is to ensure that the inhabitants will be safe in case of earthquake. An antiseismic house can be damaged, but it can never fall in on its owner’s head!
Wanted internationally
With a terrible roar, the countryside was damaged and towns and villages destroyed. Rognes, SaintCannat, Lambesc, Vernègues, Pelissanne, villages of Provence, were destroyed.
25 july 1855
The strongest earthquake recorded in the region, felt in a large area. Around 640 deaths and hundreds injured. Epicenter in the sea off the coast of Imperia.
20 july 1564
Grade:VIII-IX Victims:1
Many castles and almost all buildings in Basel destroyed. The destruction spread between 15 and 30 km. Also damaged the towns of Liestal and Sissach.
11 june 1909
Grade:VIII Victims:800
23 february 1887
The “Nice” earthquake, destroyed several villages; among them La Bollène, Roquebilliere, Belvédère and Clans. Felt in Piemonte and Liguria.
Grade:IX Victims:640
6 april 2009
Grade:VIII-IX Victims:46
w w
e .
Grade:IX-X Victims:308
Strong earthquake, followed by a long sequence. Strong damage in Val Pellice; moderates damage in the Hautesalps area. Felt in Liguria and Switzerland.
1 november 1755
Grade:XI Victims:62 000
2 april 1808
w
Grade:VIII Victims:2
The earthquake of 1 November 1755, one of the strongest and most significant in European history, destroyed Lisbon and was felt all around Europe; in North Africa there were very serious damage. The earthquake was followed by a tsunami.
24
r u d
Grade:IX-X Victims:300
Two very strong shocks destroyed Catania and 70 other localities; some, such as Noto, were then rebuilt elsewhere.
23 november 1980
Grade:X Victims:3 000
28 dicember 1908
9-11 january 1693
Grade:XI Victims:54 000
Grade:XI Victims:80 000
Strong earthquake followed by a long sequence. The historical center of L’Aquila and several villages seriously damaged.
k s i
In 1964, in Alaska, there was one of the most frightful earthquakes of all time. It was so violent that the layer of rock under the cliffs in the area liquefied, forming liquid rock! This phenomenon occurs at times in the worst earthquakes, such as the one that struck Turkey in 1999.
In 1883 an island exploded. It was Krakatoa, an island in Indonesia. The cause was a volcanic eruption. The explosion, heard as far away as 4 000 kilometers, provoked a tsunami 30 meters high, which swept away many villages on the surrounding islands.
In 1970, in Peru, an extremely powerful earthquake caused an avalanche of rock and snow on Mount Huascaran. The landslide fell for 1 000 meters and killed nearly 20 000 people.
The earthquake that struck Tokyo in 1923 caused a gigantic fire. The fire swept through the houses made of wood and paper, causing the death of 200 000 inhabitants.
The latest to arrive
Some 860 localities struck in Irpinia and Basilicata. Very severe damage. 10 000 injured. Felt all over Italy.
Messina, Reggio Calabria and about 40 towns along the Straits-destroyed. Severe damage in Calabria and Sicily as far as Etna. Felt as far as Malta and Albania.
See how the worst European earthquakes of the this century and the last, each with its epicentral intensity, have occurred in time. The most recent one is lacking. Do you remember the year when it happened? The most recent earthquake of the new century struck on April 6, 2009 in Abruzzo (Italy).
Damage to Visp, Törbel, Visperterminen St.Niklaus Grächen and Stalden. 200 buildings damaged, 1 dead and many people injured.
18 october 1356
t i .
The earthquake of 2003 in Algeria released an enormous amount of energy (Magnitude 6.9), equivalent to the explosion of… • 15 bombs dropped by a bomber plane. • 1 atom bomb like the one dropped on Hiroshima. • 15 atom booms like the one dropped on Hiroshima. • 150 hand grenades. 15 atomic booms like the one dropped on Hiroshima.
Luckily for us, the worst earthquakes happen in other parts of the world. But Europe too has had its share, as we have seen. Let’s take a closer look at some of the ugly ones that have knocked out many areas in the last thousand years. Their violence has been estimated on the intensity scale.
As you can imagine, there has been an enormous number of earthquakes in the history of the world. As usual, most of them have always been concentrated in the same zones along the boundaries between continental plates, as we know by now. Some have been more catastrophic or stranger than others. Here are a few examples.
Under the rubble
To find people who are still alive but imprisoned by a collapse, there is a special infrared-ray telecamera that can recognize a human body by the heat it emits.
A special device is used by rescuers to detect the vibrations of a human being trapped under the ruins, and to find him. With this device the rescuers can also talk to the person.
Is it true that before an earthquake strange weather conditions occur, such as a sudden hot wind or fog?
Hurry up!
26
Is it true that animals can “feel” an earthquake coming?
Dogs are not highly technological, but for years they have been trained to find the survivors of a collapsed building. They have a very important job!
After an earthquake there is likely to be a lot of confusion. Try to keep calm.
In some hard-to-reach areas helicopters are successfully used, although they may be hindered by bad weather.
But you already know how to behave, don’t you? This is a common belief, but there is no relationship between weather conditions and earthquakes.
w w
k s i
Animals may become restless and emit sounds when they feel the first vibrations in the soil, weaker than the ones that will come later. But it has not been demonstrated that they can feel an earthquake before it arrives.
Civil Protection personnel enter into action immediately after the earthquake. Civil Protection includes many operational centers and a large number of forces: the Fire Department, the Armed Forces, the Police, Volunteers, and Emergency Health Services. Their tasks are many, all highly useful and complicated. Looking for survivors and rescuing them, taking care of them, organizing tents and hot meals for those who have been left without a home, restoring interrupted communications and roads, removing rubble and repairing damage. In a word, trying to get back to normal as soon as possible.
w
r u d
e .
Emergency
t i .
Does an earthquake make noise?
Yes, sometimes you can hear strong rumbling. It is caused by vibrations in the soil, and announces the arrival of more violent tremors.
Don’t worry, somebody is thinking of you. In Europe the work of many people centers on earthquakes. As we have seen, some experts study in detail the geological zones where these phenomena are known to occur. Others are concerned with A very strong tremor? limiting damage as far as possible, by checking the Okay! We have to act condition of houses or organizing a rescue immediately! network that can take action sooner and more effectively than in the past. As soon as any earthquake begins, the researchers of the seismic networks take its measurements: epicenter, magnitude, date and time. If the earthquake is an important one (with magnitude of 2.5 or over), all of the information, along with an estimation of the damage in the area involved, is transmitted to the Civil Protection.
One of the riskiest jobs is finding people who are buried under the rubble. Rescuers don’t always know where to look, and they themselves may be the victims of further collapse. Broken gas pipes can cause fires that worsen the danger. And people who have been buried by rubble may not be able to call for help. In this case the rescuers have to dig through the ruins with their hands, even for days. Today there are techniques for carrying out this more effectively.
A few more things
Will it happen? Or not? We can’t always be worrying about it. But there are some things to be done, not only during and after an earthquake, but also before, that you should know about. Because sometimes just knowing those few things can save your life. If you have read this far, you have already done one of these important things: you have read this book, which means you have found out something about the subject. What else should you do to feel like a real E.E. (Earthquake Expert)? Read on!
r u d
Whether you like it or not, the town where you live has been classified (by some other E.E.) according to its seismicity, that is, the probability that it will experience another earthquake. The experts have taken account of all of the earthquakes that have occurred in that place, of how strong they have been and the damage they have caused. Do you know the seismic zonation of your town? Apart from curiosity, it is useful to find out, by looking for the latest updated records. Ask your teacher, or carry out a research project. For now you should know that every town in Europe belongs to one of the following zones:
e .
w w
Zone 1: the most hazardous
In the past this town has even been destroyed by earthquakes. To keep this from happening again, very strict regulations for building new houses have been passed.
Zone 2: requires a great deal of caution In this town there have been quite strong earthquakes and damage, and here too the houses must be able to withstand new shocks.
w
k s i
Find out if your town has a Civil Defense plan that explains what to do in case of disaster.
Prepare an emergency plan in your family too, to decide where to meet in case of earthquake
Know where the gas, electricity and water switches are, since they should be switched off before leaving the house.
Keep a first aid kit in the house. And along with it, a flashlight, a fire extinguisher and a battery-operated radio.
Zone 3: requires attention
This town has had little damage in the past and there is a possibility of moderate tremors. Well-built houses usually have no problems.
Zone 4: the least hazardous
28
In this town the chances of damage are low, but since a small seismic tremor can happen anywhere the public buildings (schools and hospitals) are regularly inspected.
The colors of Europe
Here is Europe divided into four colors. What does each color mean? Each color represents the seismic zone in which each municipality is classified (as you can see on the opposite page).
How are you classified?
t i .
A house built according to antiseismic regulations should: • Always remain intact. • Remain standing. • Reject earthquakes Remain standing.
If your town is in a high-risk zone, you had better follow the advice given below! But even if it’s not, it won’t hurt to take a look at this advice, with your teachers or parents. Because – you never know!
Can you pick out the zone you live in? Fasten furniture and heavy objects to the wall. Put only lightweight objects on shelves.
Ask your teacher to explain the emergency plan of your school, and how to behave in an emergency situation.
G. After a tremor you should phone the Fire Department immediately:
❐ ❐ ❐
True, it will let them take action at once. False, it’s better not to use the phone at all. False, you should call the Civil Protection.
t i .
H. It is possible to predict when an earthquake will occur: The lesson is over! Now we can say it: we’re sick and tired of these earthquakes! We hope we’ll never see one. But, if you have nothing better to do, here is a test to see if you have really become an E.E. (Earthquake Expert) or if you need to study a little more.
A. Magnitude and intensity are how earthquakes are measured:
❐ ❐ ❐
r u d
False, because both of them serve to measure rainfall. True, magnitude measures the force of an earthquake, intensity measures the severity of its effects. False, magnitude measures the fear that an earthquake causes, intensity measures its duration.
B. A tsunami is an exceptionally strong tide:
❐ ❐ ❐
False, it is a territory where earthquakes strike every year. False, it is a territory that has been struck by earthquakes in the past. True, although you never can tell!
e .
w w
D. If you are at home when a tremor is felt, it is usually better not to go out:
❐ ❐ ❐
True, if the house is well-built it is better to wait for the tremor to end. False, you can go out but very cautiously. False, you can go out but you should use the elevator.
w
❐ ❐ ❐
True, they are severe and they happen very often. False, but they do occur more often than in other places. False, but they cause a lot of damage because the houses are inadequate.
L. When an earthquake strikes there is nothing we can do about it:
False, it is a downpour caused by a hurricane. True, it is caused by big ships. False, it is gigantic wave caused by underwater earthquakes and landslides.
C. A seismic zone is always safe from earthquakes:
❐ ❐ ❐
k s i
I. In Europe earthquakes are more severe than in other parts of the world:
❐ ❐ ❐
False, we can run away as fast as we can! True, we can only hope for luck! False, we can try to use our heads and follow the emergency plans! Solutions A-2 / B-3 / C-2 / D-1 / E-3 / F-2 / G-2 / H-1 / I-3 / L-3
❐ ❐ ❐
False, you can only imagine that it could happen again in a certain place. True, but only if it is a big earthquake. True, although you can’t know the exact time.
Count the right answers and discover whether you are earthquake-proof! From 8 to 10 points
From 5 to 7 points
From 1 to 4 points
0 points
You have learned to understand earthquakes and tremors, and should one occur you would be keep your head, like a real E.E.!
You know enough not to be scared by these big stupid giants. You are smarter than they are!
Earthquakes, tremors and In the event of an earthquake, shocks are still a mystery your only hope is to you. Don’t be discouraged, to be real cute! Just joking, but try again: you’re on don’t you think it might be the right track! useful to learn a little more?
E. If you are outdoors when an earthquake strikes, you should take shelter under a bridge:
❐ ❐ ❐
True, as long as the bridge is solid. True, but when the tremor ends you have to move away immediately. False, because the bridge could collapse.
F. Earthquakes are caused by underground explosions:
❐ ❐ ❐
30
False, they are caused by volcanic eruptions. False, they are caused by the breaking of rocks underground. True, the explosions are caused by gases.
And if you really like earthquakes...
Websites www.edurisk.it News, curiosities, documents, work materials and links about earthquakes and volcanoes.
r u d
www.protezionecivile.it The Italian Civil Protection Department, official site. www.ingv.it The National Institute of Geophysics and Volcanology, official site. The INGV, carries out research and guarantees seismic and volcanic surveillance across Italy. www.emsc-csem.org EMSC - European-Mediterranean Seismological Centre. Plenty of real time earthquake information here to know about seismic events as they happen.
e .
www.seismo.ethz.ch The official site of the Swiss Seismological Service (SED). Earthquakes in real time, catalogues and hazard maps.
w w
www.sisfrance.net The history and characteristic of earthquakes in France and access to SIRENE database.
o3e.geoazur.eu The O3E site (Environment observation for educational purposes in schools). This site contains data registered by school network stations and information on educational material which has been approved by scientists and experts in the sector.
w
32
...you can find more of them here!
k s i
t i .
A notebook like an umbrella This is a strange kind of notebook: it’s not just something to read and learn from. It also serves for exploring, and for protecting. Because nature has a thousand ways of enchanting, amazing or terrorizing. Often we blame nature for disasters, forgetting that we are guests, along with others, of this mistreated planet. Events such as hurricanes, floods, and EARTHQUAKES become catastrophes only when human beings do not use their brains and their sophisticated technologies to respect nature’s cycle, but to control and exploit it instead. If we live in a place where it rains very often, we will keep within reach something to shelter us, an umbrella, a raincoat; or at worst, we know that we are going to get wet. But strange to say, with earthquakes many people think they can behave differently. As if they had rather catch cold than bring an umbrella with them. This notebook is designed to be used as an umbrella: to know whether it rains often, to be ready when it does rain, and to make sure that the rain falls without causing too much damage.
r u d
O3E’s staff
t i .
k s i
EDURISK means educating about risks; particularly seismic and volcanic risks. EDURISK is a project, promoted by the Department of Civil Defense, which offers tools and educational programmes to schools with the objective of reducing risks. Earthquake lesson is one of the tools produced by the programme for elementary schools.
Original title: A lezione di terremoto Editorial Project: M. Cristina Zannoner, Rita Brugnara, Roberto Luciani Managing Editor: Rita Brugnara Coordination and supervision for the EDURISK project: Romano Camassi, Laura Peruzza Coordination and supervision for the O3E project “Observation de l'Environnement à but Éducatif à l’École”: Emmanuel Baroux, Jean Luc Berenguer, Romano Camassi, Françoise Courboulex, Gabriele Ferretti, Jessica Le Puth, Stefano Solarino, Anne Sornette Texts and illustrations: Roberto Luciani Graphics and page format: Carlo Boschi Editing: Lucy Claire Smith Scientific Committee: Romano Camassi, Viviana Castelli, Federica La Longa, Carlo Meletti, Laura Peruzza, Vera Pessina Technical department: Elena Orsini Thanks to: André Laurenti, R. Rozbowsky, Noric Simonetti, D. Slejko Translation: Catherine Frost www.giuntiprogettieducativi.it o3e.geoazur.eu www.edurisk.it www.ingv.it www.interreg-alcotra.org
w
w w
© 2010 Giunti Progetti Educativi S.r.l., Florence/2010 INGV, Bologna First edition: January 2010 Reprint
Year
6 5 4 3 2 1 0
2014 2013 2012 2011 2010
Printed by Giunti Industrie Grafiche S.p.A. – Prato
e .
This volume was produced thanks also to contributions from the NationalInstitute of Geophysics and Vulcanology and the Department of Civil Defense.
Participating in the EDURISK project are: