Our Earth

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Ready-Ed Publications

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Our Earth © ReadyEdPubl i cat i ons comprehensive •Af o rr evi ew publackline r posesmaster onl y•

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booklet that features stimulating activities and experiments to teach middle and upper primary students all about earth science.

o c . che e r o t r s super Written by Judy Gabrovec. Illustrated by Melinda Parker.

Published by Ready-Ed Publications (2001) 11/17 Foley St, Balcatta, Perth, Australia, 6021

COPYRIGHT NOTICE Permission is granted for the purchaser to photocopy sufficient copies for non-commercial educational purposes. However, this permission is not transferable and applies only to the purchasing individual or institution.

ISBN 1 86397 352 4

Teacher ’s Information Teacher’s “Our Earth” is a comprehensive blackline master booklet that features stimulating activities and experiments to teach middle and upper primary students all about earth science. The booklet is divided into five sections: The Structure of the Earth Landforms Rivers and Inland Water Coastal Landscapes The Ocean

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Each section has teacher’s notes which provide valuable background information for each of the different activity pages. These notes will save teacher preparation and research time as they provide the answers to any questions or research that is required on the activity page. There are some suggested Internet sites to visit on some of the pages but all the activities can be completed without access to computer technology.

Students will have the opportunity to practise many different skills when completing the activities in “Our Earth” including:

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dictionary skills; making comparisons of models, maps etc; labelling diagrams; map reading; atlas skills; matching text explanations to diagrams; making predictions; jigsaws; model making; interpreting text using diagrams; following procedures when doing an experiment; recording results of an experiment; designing an experiment for a given purpose; interpreting the results of an experiment; interpreting diagrams in text format; research; recording the results of an experiment using diagrams; and relating experiment to actual events.

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Contents Teacher’s Information ................................................................................. 2 Teachers’ Notes: The Structure of the Earth ............................................ 4 The Earth’s Structure ................................................................................. 5 The Earth’s Crust ...................................................................................... 6 Tectonic Plates .......................................................................................... 7 How Tectonic Plates Move ......................................................................... 8 Pangaea .................................................................................................... 9 Pangaea, The Earth’s Jigsaw Puzzle ...................................................... 10 The Ring of Fire ....................................................................................... 11

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Teachers’ Notes: Landforms .................................................................. 12 Landforms ............................................................................................... 13 Plateaus and Plains ................................................................................ 14 Mountain Ranges .................................................................................... 15 Fold Mountains ........................................................................................ 16 Block Mountains ...................................................................................... 17 Dome Mountains ..................................................................................... 18 Volcanic Mountains ................................................................................. 19 Geysers and Hot Springs ........................................................................ 20 Volcanic Activity ...................................................................................... 21

Teachers’ Notes: Rivers and Inland Waters ............................................ 22 River Formation ....................................................................................... 23 River Valleys ............................................................................................ 24 Waterfalls, Rapids and Plunge Pools ...................................................... 25 Loops and Lakes ..................................................................................... 26 Deltas ...................................................................................................... 27 Create a Model of a River Landscape ...................................................... 28

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Teachers’ Notes: Coastal Landscapes ................................................... 29 Coastal Landscapes ................................................................................ 30 The Work of the Sea ................................................................................ 31 Headlands ............................................................................................... 32 Sea Cliffs and Caves ................................................................................ 33 Sea Caves ............................................................................................... 33 Blowholes ................................................................................................ 34 Natural Bridges and Stacks ..................................................................... 35 Beaches .................................................................................................. 36 Sandbars and Lagoons ............................................................................ 37 How A Sand Dune Forms ........................................................................ 38 Sand Dunes ............................................................................................ 39 Create a Coastal Landscape ................................................................... 40

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Teachers’ Notes: The Ocean ................................................................. 41 The Ocean ............................................................................................... 42 Seas and Oceans .................................................................................... 43 Sea Waves .............................................................................................. 44 Tsunamis - the Wave Train ...................................................................... 45 Tides ....................................................................................................... 46 Coral ........................................................................................................ 47 Coral Reefs .............................................................................................. 48 Oceanic Volcanoes ................................................................................. 49 Coral Atoll Islands ................................................................................... 50 Volcanic Island ........................................................................................ 51 Revision Exercise: Which Landform? .................................................... 52

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The Structure of the Earth

The Structure of the Earth Pages 5 - 11

The Earth: Page 5 The Earth’s structure consists of three separate layers of rock material. The first layer is the earth’s “skin” or crust. This is the relatively thin outer rock shell which contains all the earth’s landforms. The second layer is the thick mantle that lies beneath the crust and under this layer is the metallic core, which has an inner core.

r o e t s Bo r e p ok u S The Earth’s Crust: Page 6

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Tectonic Plates: Page 7

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The earth’s crust is made up of continental crust and oceanic crust which lies beneath the sea. The continental crust is relatively thick and is made mainly of granite. The oceanic crust is thinner and is made of basalt, or volcanic rock. Because the granite is lighter than the basalt, the continents lie embedded in the ocean basalt. The earth’s continental and oceanic crusts (with the upper part of the mantle) form the lithosphere which is rigid and relatively light. It can fracture and break easily.

The lithosphere is broken into a number of large slabs, much like the shell of a boiled egg that has been rolled on a table. These slabs are called tectonic plates. There are seven major tectonic plates, each one with a continent on it. Earthquake fault lines and volcanoes tend to occur at the tectonic plate boundaries because of the constant pressure and tension at these points of the plates.

How Tectonic Plates Move: Page 8

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The tectonic plates move slowly in various directions. There is a correspondence between the earthquake zones of the world and the boundaries of the tectonic plates. Any sudden plate movement causes an earthquake. Most of the world’s volcanoes are also located on the ridges where the tectonic plates collide or move apart causing one plate to go under another. Hundreds of constantly active volcanoes are found along a circular area around the Pacific Ocean, which corresponds with the boundaries of the tectonic plates.

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Scientists believe that the present day continents were once a single continent with Africa at the centre. This continent was thought to have existed 200 million years ago and has been named Pangaea. It is generally accepted that over time the continents have been joined together in various configurations. Pangaea gradually broke up over millions of years to form Laurasia in the north and Gondwanaland in the south. The continental drift continued until about 60 million years ago when the modern day continents formed as tectonic plates carrying them drifted to their present position.

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Most of the world’s volcanoes are found in the Pacific Ocean in an arc of active and dormant volcanoes known as the “Ring of Fire”. The “Ring of Fire” stretches from the tip of South America, up the west coast of South, Central and North America, along the Aleutrian Islands, Japan, the Marianas, Philippines, along Indonesia, Papua New Guinea, Tonga and ending at New Zealand.

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The Structure of the Earth

The Earth’s Structure

Use a dictionary to find out what these key words mean:

• landforms ...........................................................................................................

• metallic ...............................................................................................................

• core ....................................................................................................................

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• mantle ................................................................................................................

Cut an apple in half and look at the inside structure. There are four layers of an apple - the skin, the pulp, the core and the apple’s centre or inner core.

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The earth, like the apple, is made up of four layers.

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1. The crust, which is the thinnest and contains all the earth’s landforms.

2. The mantle, which is thicker and lies beneath the crust.

3. The earth’s metallic core.

4. The inner core.

Using this information, label the diagram of the earth’s structure.

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Inner core

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Visit this Internet site to learn more about the earth’s structure: volcano.und.nodak.edu/vwdocs/vwlessons/lessons/Earths_layers/Earths_layers2.html Ready-Ed Publications

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The Structure of the Earth

The Earth’s Crust

Use a dictionary to find out what these key words mean.

• continental ..........................................................................................................

• oceanic ...............................................................................................................

• profile .................................................................................................................

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• rigid ....................................................................................................................

• brittle ..................................................................................................................

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The earth’s crust is made up of continental crust and oceanic crust which lies beneath the sea.

Look at the diagram of the earth’s crust in profile. Identify the continental crust and the oceanic crust.

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The earth’s crust and the upper part of the mantle form a rigid and brittle layer on the earth’s surface which is broken into a number of slabs called tectonic plates.

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Eggsperiment!

Take a hard boiled egg and roughly draw the seven continents on it. Colour the rest of the egg blue to show where the oceans are on the earth. Roll the egg on a desk, allowing the shell to crack slightly.

. te o ......................................................................................................................... c . c e her ......................................................................................................................... r o t s su“eggsperiment”. per Answer these questions about the Describe what happens to the egg. ............................................................

1. What do the broken parts of the egg shell represent on the real earth? ......................................................................................................................... .........................................................................................................................

2. Did the egg shell crack on the oceans as well as the land? ........................

3. Do you think this is what happens on the real earth? ...................................

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The Structure of the Earth

Tectonic Plates

The earth’s crust is broken up into seven big parts and eight or more smaller parts. These parts are called tectonic plates.

The map below shows the world’s continents and the seven major tectonic plates.

What are the seven continents? ......................................................................

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............................................................................................................................. .............................................................................................................................

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Label the continents on the map. What do you notice about the position of the continents and the tectonic plates?

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Scientists believe the movement of these tectonic plates influence the formation of landforms and occurrence of natural disasters. Look at the map below of the earthquake zone. Compare this map to the map of the earth’s tectonic plates.

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What do you notice when you compare the two maps? ....................................... .............................................................................................................................

Picture Galley To view some satellite pictures and some photographs of some volcanoes go to: hawaii.ivv.nasa.gov/space/hawaii/vfts/kilauea/kilauea.vfts.html Ready-Ed Publications

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The Structure of the Earth

How Tectonic Plates Move

Look up these key words in the dictionary.

• thrust ..................................................................................................................

• rift .......................................................................................................................

• boundary ............................................................................................................

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• horizontally .........................................................................................................

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Tectonic plates move in different ways at their boundaries.

• The tectonic plates can slip or move horizontally.

• Plates can collide together.

• The plates can thrust up against each other.

• A rift can cause the plates to separate.

Look at the diagrams of the tectonic plate movement. Using the information above, identify the different types of movement.

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What natural disaster do you think could occur if the tectonice plates slipped c h r against each other? er o t s s r u e p .............................................................................................................................

Movement ........................................

Movement ............................................

What do you think could be formed as a result of tectonic plates colliding against each other? .............................................................................................................................

Faulty Facts Find out some very interesting facts about earthquakes at this site: http://wwwneic.cr.usgs.gov/neis/eqlists/eqlists.html Page 8

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The Structure of the Earth

Pangaea

Over 200 million years ago, the seven continents of earth were one land mass called Pangaea. It is believed that because of the movement of the tectonic plates this one land mass drifted apart to become the seven continents.

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Look at the map of Pangaea. Using an atlas see if you can identify which land mass formed each continent. Label the map with the continents.

These diagrams show how the pieces of Pangaea moved.

Label the continents in each map.

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Over 200 million years ago.

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60 million years ago.

Explore Further!

Visit this web site to discover more about the ancient land of Pangaea: kids.mtpe.hq.nasa.gov/archive/pangaea/index.html Ready-Ed Publications

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The Structure of the Earth

Pangaea The Earth’s Jigsaw Puzzle

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Cut out the world puzzle pieces and use them to construct the super continent, Pangaea.

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o c . che e r o t r s super Online Jigsaw

To complete an online jigsaw puzzle of the ancient land of Pangaea, visit this Internet site: kids.mtpe.hq.nasa.gov/archive/pangaea/Pangaea_game.html Page 10

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The Structure of the Earth

The Ring of Fire

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Most volcanoes are located on the ridges and boundaries of the earth’s tectonic plates. (See page 7.)

Look at the map below that shows the location of the volcanoes that form “The Ring of Fire”.

Use an atlas to locate the oceans and the continents on the map.

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Why do you think the volcanoes in this area are called “The Ring of Fire”?

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Antofalla

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Cotopaxi

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Sangay

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Mauna Loa

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Find out what country these volcanoes are in and when they last erupted.

Place them on the map.

Volcano

Question Time!

Find out why people still continue to live near volcanoes even though they are so destructive when they erupt.

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Landforms

Landforms Pages 14 - 20

Plateaus and Plains: Page 14 Plateaus or continental shields are large, elevated, relatively flat and rocky landforms. They are the foundations of the continent and consist of very old rock. Examples of extensive plateaus include the Canadian Shield in North America, the Baltic Shield in Europe, the Siberian Shield in Asia and the Great Western Shield in Australia. Plateaus are now mostly geographically inactive with any mountains that have been formed in the past worn down by the processes of erosion.

r o e t s Bo r e p ok u S Mountain Ranges: Page 15

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Plains are tracts of low-lying land that are found at either edge of the continents as coastal plains, or as river floodplains at the sides of rivers, such as the Ganges riverplain in northern India. Plains are built by the depositing of material and sediment from the oceans and rivers and this is why they occur in coastal and river areas. They are a much younger landform than plateaus and mountains.

Mountain ranges are formed at the boundaries of the tectonic plates where the plates converge.

The converging of the plates produce great pressures which buckle the crust forming the mountain ranges.

Fold Mountains: Page 16

Fold mountains are relatively young mountains that are created when two tectonic plates collide and one plate goes under the other. All the land, rocks and water between the two plates are pushed upward and crumble into enormous folds. The Andes Mountains in South America are an example of fold mountains created by the collision of an oceanic plate and a continental plate.

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Many of the world’s block mountains and rift valleys were formed by the slippage of blocks of brittle continental crust up or down along the fault lines caused by the forces of compression or tension (pulling apart). Sometimes major rift valleys are formed mid-continent, where a single continental landmass splits and diverges to form two land masses. A rift valley is formed because some of the blocks of rock slide upwards (horsts) and some slide downwards (graben).

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Landforms

Landforms Pages 14 - 20

Dome Mountains: Page 18

r o e t s Bo r e p ok u S Volcanic Mountains: Page 19

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Molten rock or magma push up to the top layers of the earth’s crust but does not break through the surface. The magma solidifies below the surface of the earth, forming a dome-shaped mountain.

Volcanic mountains form when magma builds up under the earth’s surface and is forced up along faults and weak points in the crust. The magma collects in the magma chamber along with gases released from the melting rock. Pressure continues to build and the magma eventually erupts, as lava flows through the opening in the earth’s surface. Lava piles up around the vent to form the volcanic cone.

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o c . che e r o t r s21 su r pePage Volcanic Activity Geysers and Hot Springs Page 20

Geysers and hot springs occur in volcanic areas. Underground water is heated by the hot rocks which have been heated by the magma. The water can bubble to the surface as a hot spring, or can sprout high in the air as a geyser - a jet of steam and scalding water.

Volcanoes are either active (erupting), dormant (sleeping) or extinct (no record of eruption).

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Landforms

Plateaus and Plains

Use a dictionary to find out what these key words mean.

• continents ...........................................................................................................

• elevated .............................................................................................................

• erosion ...............................................................................................................

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Plateaus are the building blocks of the continents of the world. They are large, elevated, flat, rocky landforms made up of very old rock. There are very few mountains or raised landforms on a plateau, as erosion has long since worn them down.

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Plains are areas of low-lying land that are found at the edge of continents or at the sides of rivers.

Use an atlas to find out which continent these plateaus and plains are in:

Canadian Shield Great Northern Plain Ganges River flood plain

Great Western Plateau Baltic Shield Siberian Shield

Locate the above plateaus and plains on the world map below.

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o c . che e r o t r squestions. su er Use the information from the map to p answer these

Which continents have plains covering more than 50% of their land mass? .............................................................................................................................

Which two continents are covered by more than 50% plateaus? .............................................................................................................................

Why do plains occur in coastal areas and by the sides of rivers? .............................................................................................................................

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Landforms

Mountain Ranges

Mountains are portions of the continental crust that rises above the land surface to a height of at least 600 metres. Mountains usually occur in a group, or as a mountain range or chain.

They usually occur at the boundaries of the world’s tectonic plates.

Use an atlas to locate the following mountain ranges on the world map.

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Ural Mountains, Alps, Atlas Mountains, Rocky Mountains, Appalachians, Himalayas, Great Dividing Range, Pennines, Southern Alps, Andes.

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These are the highest mountains from each of the continents and some island nations. Find out what mountain range they belong to, how high they are and locate them on the map.

Continent Africa Antarctica Asia

. teMountain Mountain Range Height o c .

Kilimanjaro ............................... che ...............................r e o ...............................

Vinson Massif ............................... r st su per Everest

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Australia

Kosciusko

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North America

McKinley

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South America

Aconcagua

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Europe

Elbrus

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New Zealand

Cook

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Landforms

Fold Mountains

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1. Mould 4 different coloured Plasticine strips into 4 balls to represent different layers of rocks.

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Make a Fold Mountain

2. Roll each ball with a rolling pin until it is about 1.25 cms flat.

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o c . che e r o 3. Place the layers on top of one 4.

Push each end of the t r s s r u e p another and trim the edges.

Plasticine together to form a ridge.

Describe the mountain that you have modelled. .................................................. .............................................................................................................................

Why do you think mountains that are formed in this way are called “fold” mountains? ............................................................................................................................. .............................................................................................................................

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Landforms

Block Mountains

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Block mountains are smaller than fold mountains. They form when cracks or faults in the earth’s crust force some blocks of rock up and others down. The blocks of rocks that slide up are called horsts and the blocks of rocks that slide down are called graben.

Finish labelling the diagram of the block mountains.

What landform is created where the land slides down?.......................................

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Some examples of mountains and rift valleys formed in this way are the Ethiopian Plateau, Kenyan Highlands, Sierra Nevada Mountains and the Great Rift Valley. Locate them in an atlas and place them on the map.

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Landforms

Dome Mountains

Look up these words in the dictionary and discuss their meaning.

• currents ..............................................................................................................

• magma ...............................................................................................................

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Dome mountains are formed when swirling hot currents of magma push upwards but cannot break through the earth’s crust. The magma spreads out into layers under the surface forming a large dome-shaped mountain.

Study the diagram below which shows the formation of a dome mountain.

Label each diagram and write a caption to explain what is happening.

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Landforms

Volcanic Mountains

Look up these key words in a dictionary. Some words have more than one meaning so make sure the meaning you write has to do with volcanoes.

• magma ...............................................................................................................

• lava.....................................................................................................................

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• mantle ................................................................................................................

• conduit ...............................................................................................................

• cinders ...............................................................................................................

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1. Cinder cones - they are made mostly of cinders and rock.

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Volcanic mountains are formed when gases in hot magma are forced up through a crack in the earth’s crust. Lava slowly pours out of the opening or erupts out forming a cone-shaped mountain. There are three types of volcanoes 2. Shield volcanoes - they are made of slow moving lava flows. The lava from a shield volcano is runny, so the lava flows over a large area.

3. Composite volcanoes - they are built up of rock particles and flowing lava.

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Label this diagram of a volcano.

o c . che e r o t r s super See some real volcanic action!

To see some lava flows and erupting volcanoes, visit this Internet site: volcano.und.edu/vwdocs/movies/movie.html Ready-Ed Publications

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Landforms

Geysers and Hot Springs

Hot springs occur when underground water is heated up by hot rocks beneath the surface. The boiling water rises through cracks in the ground.

Geysers are hot springs that spout water and steam at regular intervals.

In what areas of the earth do you think it is most likely that hot springs or geysers can be found? Why? .............................................................................................................................

r o e t s Bo r e p ok u S Make a Geyser

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(This experiment should be done as a class demonstration or under strict adult supervision.)

Equipment: a flask a 30 - 40 cm glass tube rubber stopper to fit the flask flask holder a Bunsen burner or hot plate strong plastic container putty

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Procedure: 1. Fill the flask 3/4 full of water. Insert the stopper in the flask.

2. Insert the glass tube into the stopper so it reaches about 3/4 of the way down the flask.

3. Make a hole in the plastic container and gently put the other end of the glass tube in the hole so it extends about 4 cms into the bowl. Seal with putty.

4. Place the flask on the Bunsen burner or hot plate. Support the plastic bowl with the flask holder.

5. Pour water down the glass tube until the flask and the glass tube is full.

6. Turn on the heat and wait for the geyser to erupt through the glass tube.

7. The plastic container will catch the water safely.

. te o c Answer these questions about the experiment. . c e r 1. How long did it take forh the geyser to erupt?.................................................... e o t r s sueruption? er 2. What happened to the water after thep ..............................................

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3. Explain how you think changing the length of the glass tube will affect the experiment. ............................................................................................................................. ............................................................................................................................. .............................................................................................................................

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Landforms

Volcanic Activity

Volcanoes are classified as active, dormant, intermittent or extinct.

What do you think each of the terms mean? active .................................................................................................................... dormant ................................................................................................................

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intermittent ............................................................................................................ extinct ...................................................................................................................

Using some resources from the school library, give a definition of each of the terms.

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active ....................................................................................................................

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dormant ................................................................................................................ intermittent ............................................................................................................ extinct ...................................................................................................................

Make an Erupting Volcano

Materials: paper plate clay or modelling dough toilet roll baking soda or bi-carbonate of soda vinegar red food colouring

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Instructions: 1. Build a mound of clay using the paper plate as a base.

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2. Leave an opening in the centre of the mound to represent the central vent of the volcano.

. teroll into the opening.

3. Insert the toilet o c .

4. Push into the sidesc of the mound with a pencil to make openings that e h r represent the side ventse of the volcano. Make sure you pierce the toilet roll o t r s s per with the sharp end of the pencil u 5. Fill the tube with baking powder or bicarbonate soda.

6. Add some red food colouring to the baking soda.

7. Add vinegar to the baking soda and watch the eruption!

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Rivers and Inland Waters

Rivers and Inland Waters Pages 23 - 28

River Formation: Page 23 A river forms from rainwater that collects on mountains or hills, from melting snow or from underground water. It runs downhill and at the bottom of the hill it is joined by other streams and becomes a larger river. At this point it flows more slowly and winds across the country to the sea.

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A young river is relatively quick flowing and has few bends and turns as it finds the path of least resistance to the sea. As the river ages and erosion takes place, it develops loops where the force of the river has worn away the banks. Older rivers often have oxbow lakes that have been formed by erosion. When an oxbow lake is formed the river takes a new pathway.

River Valleys: Page 24

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Waterfalls, Rapids and Plunge Pools: Page 25

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River valleys are formed as the water rushes along wearing away soil, rock and mud. As the river slowly cuts deeper into the rock, weathering occurs as the steep sides of the valley are worn away by rain, frost and sun. The loose bits of rock and sand fall into the river and are washed away.

Eventually the river banks become wider with a gentler slope and gradually the process of erosion wears away a whole valley.

When the river reaches a cliff which drops away sharply and steeply, the water tumbles over the cliff edge and falls straight down. The river becomes a waterfall because the cliff has been formed with hard rock and will not erode easily. There are two types of waterfall - a cascade which is a sequence of waterfalls one after another, and a cataract which is a waterfall with a single, sheer drop usually with a large volume of water flowing over the falls.

© ReadyEdPubl i cat i ons Plunge pools• or potholes are formed when the turbulent water which falls over the waterfall gradually f o r r e v i e w p u r p o s e s o n l y • carves out a deep pool in the soft rock at the bottom of the waterfall.

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Loops and Lakes: Page 26

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Rapids are made when layers of hard rock which are sloping upwards are sandwiched between two layers of soft rock. The soft rock is worn away quicker than the hard rock by the action of the water and rapids develop.

A river flowing over flat land will meander, finding the easiest route to the sea. As the river wears away the outside of each loop, it builds up the inside and the meander becomes U-shaped.

Eventually the river wears through the meander and flows in a straight line again. The meander is cut off from the river and forms a horseshoe-shaped lake called an oxbow.

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As the river meets the sea, it has reduced energy and all the silt and sand it has carried with it on its journey is deposited at the mouth of the river. This depositing of sediment forms an extensive fanshaped area of alluvial material called a delta.

If the sea is relatively calm and shallow, the river deposits its load in the shallow water forming small islands and claw-like projections. If the sea is deeper and the ocean conditions rougher some of the sediment will be washed away by the turbulent sea and a triangular-shaped delta is more likely to form. It is this type of delta which has the shape most closely resembling the Greek letter ‘delta’, after which this landform is named.

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Ready-Ed Publications

Rivers and Inland Waters

River Formation

A river may begin as melting snow on a mountain top or as a spring of underground water, bubbling out of a crack in the side of a mountain. The water goes down the mountain and joins other trickles of water until it becomes a wider, faster-moving stream. The stream eventually becomes a river that flows to the sea.

r o e t s Bo r e p ok u S How Old is a River?

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Teac he r

Look at the river below at different stages of its development.

Describe the features of each river.

Features © ReadyEdPu bl i cat i ons ........................................................ ........................................................

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Features

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. t eoldest? ...................................................................................... o Which one is the c . e Explain your answer.c ............................................................................................ her r o t s super .............................................................................................................................

Which river do you think is the youngest? ............................................................

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All About the Rivers of the World Here is an excellent Internet site to visit to learn more about rivers: mbgnet.mobot.org/fresh/rivers/index.htm Ready-Ed Publications

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Rivers and Inland Waters

River Valleys

How a River Valley is Formed

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Fill a tray with sand and create a water outlet in one corner. Form a mound of sand at one end of the tray. Pour a jug of water down the ‘mountain’ towards the water outlet.

What landform does the mound of sand represent? ...........................................

How did the material in the tray change as water moved through? ......................

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What happened to the material that was at the top of the mound of sand? ..........

What would happen if the quantity of water was increased? ................................

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As the river flows towards the sea, bits of rock and soil are carried away by the rushing water. Eventually this weathering away of the rocks and soil forms a river valley.

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Look at the diagrams below showing the formation of a river valley.

On the back of this sheet, describe what is happening in each diagram.

1.

water

rock and soil

3.

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4.

Ready-Ed Publications

Rivers and Inland Waters

Waterfalls, Rapids and Plunge Pools

Find out the meanings of these key words.

• erode .................................................................................................................

• vertical ................................................................................................................

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• turbulent .............................................................................................................

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hard rock

turbulent water

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Waterfalls are formed when the river flows over a layer of hard rock and then over softer rock. The river wears away the softer rock faster then the harder rock, making a step. If the step is vertical a waterfall forms. When the erosion or wearing away occurs at a more gentle slope a rapid forms. There are two types of waterfall - a cascade and a cataract. Find out what the difference between them is.

soft rock

© ReadyEdPubl i cat i ons pothole • f orr evi ew pur posesonl y•

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Look at the diagram of the waterfall above. Why do you think the pothole or plunge pool has formed at the bottom of the waterfall?

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Rapids .

Look at the diagram below of the formation of rapids. Label the diagram t e o using the following terms. c . river, turbulent water, soft rock, hard e rock. ch r er o t s super

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Page 25

Rivers and Inland Waters

Loops and Lakes

As a river flows towards the sea it slows down. When it reaches the plains, the river can eventually wear away the banks to form a loop or meander. Over time, the river wears through the land and flows in a straight line again. In this way a horseshoe shaped lake called an oxbow is formed.

Use the information to write captions for these diagrams which show an oxbow developing. Label the diagrams to help your explanation.

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1.

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Ready-Ed Publications

Rivers and Inland Waters

Deltas

The beginning of a river is called its head and where it flows into a lake or sea is called its mouth. A delta forms at the river mouth where the river deposits its load of sand and soil.

Why do you think the river has lots of sand and soil in it when by the time it reaches the sea? .............................................................................................................................

r o e t s Bo r e Experiment p ok u S

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Teac he r

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Equipment: a plastic tube cut in half lengthways; an icecream container a sand pit or large container of sand; water

Procedure: 1. Cut a U-shape in the icecream container to match the shape of the plastic tube which has been cut in half lengthways.

2. Connect the plastic tube to the container.

3. Dig a hole in the sand pit and place the bowl and tube in the hole.

4. Fill the icecream container with water.

5. Place some sand and small pebbles in the tube.

6. Run some fast running water down the tube.

© ReadyEdPubl i cat i ons •f orr evi ew pur posesonl y•

What happened to the sand and pebbles when the fast running water reached the calm water of the icecream container?

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Arcuate Delta

Bird’s Foot Delta

Look at the diagrams of the deltas.

Why do you think islands have formed in the Bird’s Foot Delta? ......................... ............................................................................................................................. .............................................................................................................................

Ready-Ed Publications

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Rivers and Inland Waters

Create a Model of a River Landscape Make a model to show the journey of a river from its head to its mouth.

Include and label the following landforms in your model:

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plains, mountains, river valleys, waterfall, rapids, plunge pool, oxbow lake, delta.

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Use the landscape below to help you plan your model.

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Ready-Ed Publications

Coastal Landscapes

Coastal Landscapes Pages 31 - 40

The Work of the Sea: Page 32 Erosion of the coastline by waves can happen in several ways. The waves, which usually contain small rocks and pebbles, break against the cliff face and slowly wear away and break off pieces of the cliff. This type of erosion is called corrasion.

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Attrition, which is when the pebbles and small rocks are worn away as they knock against the cliff and each other, explains why you can find smooth, rounded stones at the beach.

Headlands: Page 33

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Hydraulic action, which is when air is trapped into cracks as a wave breaks against a cliff, also causes coastal erosion. The force of the water squeezes the air, which pushes the rock apart, weakening the rock until it eventually falls apart. Cliffs are also worn down by the dissolving action of the sea, as sea water is slightly acidic.

Headlands are narrow capes or promontories. They can be formed when a highland coastline becomes flooded. The flooding causes bays, and the highland emerges as headlands. A drop in sea level will have a similar effect. If the erosion of the coastline occurs at different rates because there is softer rock present, a headland can be formed. The waves attack the soft rock, leaving the more resistant hard rock protruding either side of the bays as headlands.

Sea Cliffs and Caves: Page 34

© ReadyEdPubl i cat i ons •f orr evi ew pur posesonl y•

Sea cliffs are the most common landform caused by marine erosion. They are found on parts of the headland that are unprotected and exposed to wave attack. The waves seek out a line of weakness (soft rock) in the headland and begin to attack it with constant hydraulic and abrasive action. Caves are formed when the erosion eventually produces deep indentations in the cliff which, in time, becomes deeper to produce a cave.

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Cliffs and caves are usually found at the sides of the headland because the waves refract around it, concentrating their attack on one small area.

Blowholes form when a cave continues to erode until the roof of the cave has a hole in it.

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Natural Bridges and Stacks: Page 36

The continued action of waves in caves on opposite sides of a narrow headland can eventually result in a natural bridge. The erosion causes the caves to meet and partially collapse, which forms an arch. The arch is spanned by a natural bridge.

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Continued weathering and erosion of the hollow may eventually weaken the bridge causing it to collapse into the sea. The part of the cliff which is stranded in the sea is known as a stack. Unlike islands, stacks are connected to the mainland by a rock platform.

Beaches: Page 37 Beaches are collections of sediment that occur mostly in the shallow water of bays where wave energy is diffused over a large area. The energy of the waves is reduced when they hit the shallow water, resulting in sand, loose pebbles, shell fragments and mud being deposited, forming a beach.

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Coastal Landscapes

Coastal Landscapes Pages 31 - 40

Sandbars and Lagoons: Page 38 Sandbars are formed when waves deposit sediment offshore. Sandbars are formed parallel to the shore and occur where waves carrying sediment landwards meet the backwash. Lagoons form when a sandbar or any other barrier (coral reef, atoll) that is parallel to the coast encloses, or almost encloses, a body of water.

r o e t s Bo r e p ok u S How a Sand Dune Forms: Page 39

Sand dunes are formed when the offshore wind, which is carrying along the sand, is slowed down by vegetation, buildings, fences or any other obstacle.

Teac he r

To stop sand dunes from blowing away several steps can be taken:

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The shape and size of the sand dunes depend on the shape of the coastline, the composition of the sand being moved, the strength and direction of the wind and the type of vegetation or other barriers that exist along the coastline.

* Fencing off areas so that humans and animals are unable to access the area to disturb vegetation. * Planting vegetation so it is more difficult for the sand to blow away. * Prohibiting vehicles from accessing the area * Erecting wind barriers.

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© Read yE dP ub i cat i ons Sand Dunes: Page 40l Parallel sand dunes form when there is a strong onshore wind and fine sand. Transgressive dunes form when there iso no r vegetation toi stop the dunes from moving inland.

Blowout or parabolic dunes • f r e v e w p u r p o s e s o n l y • form when a storm-wave forces loose sand inland to form a horse-shoe shaped dune.

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Ready-Ed Publications

Coastal Landscapes

The Work of the Sea

The waves of the sea are constantly wearing away and changing our coastlines forming many different features like caves, blowholes and stacks.

Do the following experiment to observe the action of water on rocks.

Material: sugar cubes blackboard chalk collection of hard rocks water spray can

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Procedure: 1. Make three equal sized stacks from the sugar cubes, the blackboard chalk and the rocks.

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© ReadyEdPubl i cat i ons 2. Regularly spray each stack with the same amount of water.

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3. Records what happens to each stack.

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Discuss the results of your experiment.

Try these variations to see if they affect the result of the experiment: * Add some fine grains of sand or salt into the water. * Add some vinegar to the water to make it more acidic.

Ready-Ed Publications

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Coastal Landscapes

Headlands

Find out the meaning of this key word.

• highland ..............................................................................................................

A headland is a long, narrow piece of land that juts out into the sea.

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Teac he r

A Headland

A headland can form on a highland coast which often has a rise in land level or a drop in sea level.

Explain the relationship between rising land levels, dropping sea levels and the formation of a headland. .......................................................................................

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•f orr evi ew pur posesonl y• .............................................................................................................................

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Design a model using Plasticine and water to demonstrate the formation of headlands in the above ways. Draw a diagram of your model.

o c .

Other headlands are formed because some of the coastal rock is softer that c e her r the surrounding rock. o t s s Why do you think a headland forms when some of the rock is softer? ................ up er

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On the diagram of the headland above, label the rock areas that are hard and the rock areas that are soft.

What type of ocean conditions do you think would be more likely to form a headland? ............................................................................................................................. .............................................................................................................................

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Ready-Ed Publications

Coastal Landscapes

Sea Cliffs and Caves

A sea cliff forms on the parts of a headland where the rock is weak, or in an area that is exposed to wave attack.

What do you think “wave attack” means? ........................................................ .............................................................................................................................

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Teac he r

Diagram of a Sea Cliff

Sea Caves

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© R ad yEd P ub i c at i on s To look ate some photographs of sea cliffs lookl at these Internet sites: museum.gov.ns.ca/fossils/amazing/arisaig.htm tvl1.geo.uc.edu/ice/Image/icland/632-4.html •f orr e v i ew pur posesonl y• www.geo.duke.edu/geo41/oce050.gif

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Caves are formed when the waves attack the weak parts of the cliff face.

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Caves are usually found at the sides of the headlands. Look at the diagram above.

Why do you think caves are formed at the side of the headland rather than the end? ............................................................................................................................. ............................................................................................................................. .............................................................................................................................

Ready-Ed Publications

Page 33

Coastal Landscapes

Blowholes

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Teac he r

Caves are formed when the waves attack the weak parts of the cliff face.

Blowholes form when a cave continues to erode until the roof of the cave has a hole in it.

Label the diagram below with these terms: cliff face, wave action, headland, blowhole, cave

Blowhole Picture Gallery

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Look at these Internet sites to see some photographs of blowholes from around the world. Find some pictures of blowholes in your library resource centre. www.geocities.com/HotSprings/Spa/8089/austimages/blowholes.html www.connet80.com/~alester/tonga/AmyTonga5.html

. te that you saw at the site, or one you have actually Describe the blowholes seen. o c . ............................................................................................................................. che e r o t r ............................................................................................................................. s super .............................................................................................................................

All the blowholes have a spurt of water coming out of them. Is this spurt of water continuous? Why or why not? ............................................................................................................................. ............................................................................................................................. .............................................................................................................................

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Ready-Ed Publications

Coastal Landscapes

Natural Bridges and Stacks

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Teac he r

Natural Bridges Natural bridges form when two caves on either side of a headland erode through until an arch is formed over a hole.

Draw a diagram below to explain this process.

Use these terms to help label your diagram: headland, cliff face, wave attack, arch, caves, natural bridge

© ReadyEdPubl i cat i ons Natural Bridges on the Net Visit• thisf Internet site to v seei an example ofu a natural bridge. o r r e e w p r p o sesonl y• www.geocities.com/HotSprings/Spa/8089/austimages/natbridge.html www.geo.duke.edu/geo41/oce056.gif

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Stacks Continued erosion of the bridge may weaken it so much that it falls into the sea forming a rocky offshore island known as a stack.

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Stacks of Stacks!

Surf the net to see some wonderful pictures of stacks from coastlines around the world. www.skyfirevideo.com/nature/secrets/seastacks.html www.seattle-pi.com/getaways/020499/hikepix3.html www.enlightphoto.com/webpages/wa1/wash1_7.htm www.geo.duke.edu/geo41/oce052.gif Ready-Ed Publications

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Coastal Landscapes

Beaches

Look up or discuss the meanings of these key words.

• energy ................................................................................................................

• sediment ............................................................................................................

• depositing ..........................................................................................................

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• platform ..............................................................................................................

• foreshore ...........................................................................................................

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Beaches are formed by waves depositing sediment on the foreshore, above a platform of solid rock. They occur mainly in the shallow water of bays where the energy of the waves is spread over a large area. When the waves hit the shallow area of the shoreline, the wave energy decreases and the waves cannot carry the sediment along. They deposit it on the foreshore, forming a beach.

Beaches can be made up of sand, loose pebbles, shell fragments and mud.

Using the information from the paragraph above, label the diagram below.

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© ReadyEdPubl i cat i ons •f orr evi ew pur posesonl y•

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Describe some of the other features of this diagram. Label the features. ............................................................................................................................. ............................................................................................................................. ............................................................................................................................. .............................................................................................................................

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Ready-Ed Publications

Coastal Landscapes

Sandbars and Lagoons

Make sure you know what these words mean.

• parallel................................................................................................................

• deposits .............................................................................................................

• offshore .............................................................................................................

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• barrier.................................................................................................................

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Teac he r

Sandbars are formed when offshore deposits build up parallel to the shore.

Place five sandbars on the diagram below where you think they would be most likely to occur.

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Explain why you choose these positions to place the sandbars. ....................

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Lagoons A lagoon is a body of water that forms between the coast and a barrier that cuts the body of water off from the sea. The barrier could be a sand bar, a reef or an atoll.

Identify and label the lagoon in the diagram above.

Ready-Ed Publications

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Coastal Landscapes

How A Sand Dune Forms

Do the following experiment to discover how a sand dune forms and moves.

Equipment: a large sand tray a fan sand

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Teac he r

Procedure: 1. Place the sand in the sand tray.

2. Turn on the fan and observe what happens.

© ReadyEdPubl i cat i ons Describe the p fanu was turned on. ...................................

•what f ohappened rr evwhen i ew r p os es onl y•

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What could cause the sand to move more quickly? ................................... chdunes e r er o t ............................................................................................................................. s super What could change the shape of the sand dunes? ...............................................

What could you do to stop the sand from moving on a real beach? .....................

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Does the fan represent an onshore wind or an offshore wind? Explain. ............... ............................................................................................................................. ............................................................................................................................. .............................................................................................................................

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Ready-Ed Publications

Coastal Landscapes

Sand Dunes

Discuss the meanings of these words. You may need to use a dictionary.

• offshore .............................................................................................................

• parallel................................................................................................................

• parabolic ............................................................................................................

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• transgressive .....................................................................................................

Coastal sand dunes are mounds of wind-blown sand that occur on low-lying coasts. They form where sandy beaches are blown by offshore winds.

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The three main types of sand dunes are parallel, transgressive and parabolic.

Sand dunes form differently because of the conditions and features of the coastal area they are in.

Look at the diagrams of the different types of sand dunes below. Discuss the features of each of the sand dunes. Use the discussion points to identify each of the sand dunes accurately.

© ReadyEdPubl i cat i ons •f orr evi ew pur poses onl y• Discussion points Discussion points ........................................................

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Coastal Sand Dunes Find out all about coastal sand dunes at this site: www.geography.com.sg/coasts/dune.html Ready-Ed Publications

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Coastal Landscapes

Create a Coastal Landscape Make a model of a coastal landscape. Include headlands, cliffs, caves, blowholes, natural bridges, stacks, beaches, sandbars, lagoons and sand dunes. Label all the features of the model then choose one feature to give an explanation of how it was formed.

The diagram below of a coastal landscape will help you make an accurate model.

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Teac he r

Label this diagram before you start your model.

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Ready-Ed Publications

The Ocean

The Ocean Pages 43 - 51

Sea and Oceans: Page 43 Currents are great bands of water that flow through the oceans like rivers. In the polar regions, the currents are cold and elsewhere they are warm.

The movements of the currents are affected by strong winds, the position of the continents and the earth’s rotation on its axis. In the northern hemisphere the currents travel clockwise and in the southern hemisphere they travel anticlockwise. This is called the Coriolis Effect, named after the French mathematician who discovered the effect.

r o e t s Bo r e p ok u S Sea Waves: Page 44

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Tsunami - the Wave Train: Page 45

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Most waves are caused by the wind. Waves are really rows of hills and valleys that move across the surface of the water. The top of the wave is called a crest and the valley is called a trough. Waves do not take the water along with them as they move, the energy of the wave actually passes through the water from wave to wave. (This is demonstrated by the experiment with the marbles where the energy is passed from marble to marble until only the end marble moves. This is the same as the energy of a wave that is passed along until the wave breaks on the shore.)

Tsunamis, unlike sea waves, are caused by underwater earthquakes and volcanoes. The word ‘tsunami’ is a Japanese word that means ‘storm waves’.

© ReadyEdPubl i cat i ons •f orr evi ew pur posesonl y•

Sea waves travel through the surface of the ocean, but tsunamis affect all the water from the sea-bed to the surface. They can have a wave length of hundreds of kilometres (as opposed to a sea wave, when a big swell would only produce a wave length of one kilometre) and travel up to 500 to 800 kilometres per hour. They may only be 30 - 60 centimetres high in deep water but when they reach shallow water their force becomes concentrated and they grow to a terrifying size. They can cause immense destruction to both life and property.

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Tides: Page 46

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Because tsunamis are caused by underwater earthquakes and volcanoes they are more likely to begin in the area of the ocean where tectonic plates meet.

Tides are set in motion by the moon’s pull or gravitation. As the moon orbits the earth its gravitational pull tugs part of the ocean surface towards it, causing high tides. As the moon orbits, the high tide caused by gravitation follows it. As this is happening, another high tide occurs on the other side of the earth because the moon’s gravitational force is pulling the earth away from the water. The two high tides cause a trough between them which results in low tides in the other parts of the earth.

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As the earth turns, high tide occurs at each place on the ocean twice a day, once when the moon is directly above, and once when the moon is on the other side of the earth.

Changing positions of the moon and the sun causes extremely high tides twice a month - near the full moon and near the new moon. These tides are called spring tides and are created because the sun and moon pull together. When the sun and moon pull at right angles to each other, tides do not rise or fall as much as normal. These tides are called neap tides and they occur when the moon is at its first and last quarters.

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The Ocean

The Ocean Page 43 - 52

Coral: Page 48 Coral belongs to a group of animals called Coelenterata or Cnidaria. Coral comes in a variety of shapes and sizes and all have the same basic body structure. They have a mouth surrounded by a ring of stinging tentacles and a simple stomach. All coral have a symmetrical shape and are related most closely to sea anemones and jellyfish.

r o e t s Bo r e p ok u S Coral Reef: Page 49

Coral reefs form in warm shallow water. They are a rocklike accumulation of exoskeletons of coral animals. The reef is built up layer by layer as the living coral grows on top of the skeletons of the old coral.

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There are three types of coral reef. Fringe reefs extend outward from the shore of an island or mainland with no body of water between reef and land. Barrier reefs occur further offshore, with a channel or a lagoon between the reef and the shore. Atolls are coral islands, typically a narrow horseshoe-shaped reef surrounding a narrow lagoon.

Oceanic Volcanoes and Coral Atolls: Page 50 and 51

Where two oceanic plates or a continental plate and an oceanic plate converge an oceanic volcano can occur. This type of volcanic activity can produce an island arc such as the island arcs of Japan and the Caribbean Islands. If a volcano erupts and then has no further activity, it will sink back into the sea and a coral atoll can form on the part of the volcano that is left protruding into the sea.

© Rea d yEandIsland: PuPage bl i cat i ons The Birth of 52 Named after the Norse fire god Surtur, Surtsey is one of the world’s newest islands. It was formed after an oceanic volcano in 1963 off the of Iceland.

A crew of an nearby •f orerupted r ev i e w pcoast ur p ose so l yfishing • boat noticed some strange things: a sulphurous aroma in the air and the ocean swirling around the boat.

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Then, just before dawn, the volcanic eruption that had been increasing in intensity under the sea broke the surface and spewed lava into the air. By the next morning, the cinder cone of the volcano had broken the surface of the water and a new island had been born. The volcano continued to erupt for three and a half years. Plant life began to grow from seeds transported from the wind, currents and birds.

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The Ocean

Seas and Oceans

Sea water covers nearly ¾ of the earth’s surface. There are five oceans.

Use an atlas to find out what the five oceans are and place them on the world map. Locate the following major seas, gulfs and bays on the map.

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Black Sea, Caspian Sea, North Sea, Beaufort Sea, Norwegian Sea, Mediterranean Sea, Arabian Sea, South China Sea, Timor Sea, Coral Sea, Tasman Sea, Red Sea, Laptev Sea, Caribbean Sea, Gulf of Alaska, Baffin Bay, Hudson Bay, Gulf of Mexico, Baltic Sea, Gulf of Guinea, Persian Gulf, Bay of Bengal, Sea of Japan and the Sea of Okhotsk.

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The arrows on the map show the movement of great bands of water that flow through the ocean like rivers. They are called currents and can be made up of warm water or cold water.

The two different types of currents (warm and cold) are indicated with these symbols.

. teyou think shows the cold currents.

Draw the symbol o c .

Why are these cold currents? che.............................................................................. e r o t r ............................................................................................................................. s super

Draw the symbol you think shows the warm currents.

Why are these warm currents? ............................................................................ .............................................................................................................................

What do you think would affect the movement of the currents? .......................... ............................................................................................................................. .............................................................................................................................

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The Ocean

Sea Waves

Sea and oceans are never still. Water is always on the move, below or at the surface.

Let’s Make Waves Do the experiment below to discover how waves work.

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Procedure: Part One 1. Fill the pan with 6 cms of water.

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Materials: large flat pan about 10 cms deep electric fan or large firm paper fan water food dye 5 large marbles

2. Place electric fan about 30 cms from the pan (or hold paper fan facing the pan).

Make a prediction!

Do you think the water will bunch up at the far end of the pan?

© ReadyEdPubl i cat i ons 3. Let the fan blow over the water at low speed.

•f orr evi e w pur posesonl y• Have a discussion!

Were there waves? ..............................................................................................

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Did the water bunch up at the end of the pan? .....................................................

Did the water slosh over the pan? ........................................................................

Is what happened what you expected? ................................................................

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Procedure: Part Twoc e hside r 1. Put four marbles side by on a table. er o t s s r u e p 2. Gently roll the fifth marble and hit the marble at one end of the row.

4. Sped up the fan a little to see how it affects the waves.

What happened? Discuss.................................................................................... ............................................................................................................................. .............................................................................................................................

How can you relate this to the movement of waves?............................................ .............................................................................................................................

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The Ocean

Tsunamis - the Wave Train

A tsunami is a destructive wave or a series of waves that sweeps across the ocean like a huge tide. A tsunami is not, however, a tidal wave. Tidal waves are caused by tides or wind.

Find out what the word tsunami means and where it comes from. .............................................................................................................................

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Study this diagram of a tsunami forming and use the information to answer the questions below.

© ReadyEdPubl i cat i ons What do you think causes a tsunami if it is not caused by winds or tides? ..........

•f orr evi ew pur posesonl y• .............................................................................................................................

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In what parts of the world’s oceans do you think tsunamis are more likely to happen? Why? ............................................................................................................................. .............................................................................................................................

. te o What happens to a tsunami as it reaches the shallow waters . of the shoreline? c che e r ............................................................................................................................. o t r s s r u e p .............................................................................................................................

Find out how the length of a tsunami, and the amount of time a tsunami takes to “break”, is different from other waves.

What type of damage is it possible for a tsunami to do? ..................................... .............................................................................................................................

Find Out More!

Visit these Internet sites to learn more: www.germantown.k12.il.us/html/tsunami.html www.geophys.washington.edu/tsunami/general/physics/physics.html Ready-Ed Publications

Page 45

The Ocean

Tides

Tides are the slow, steady rise and fall of the surface of the sea that goes on every day. Water creeps up to its highest level, called high tide. Then it slips back to its lowest level, called low tide.

r o e t s Bo r e p ok u S high tide

low tide

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Discuss the information above with your teacher.

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Tides are caused mostly by the gravitational pull of the moon on earth. The moon’s gravity pulls the water which is directly beneath it, making a high tide.

There is also a high tide on the other side of the earth because the land is being pulled away from the water.

Look at the diagrams below showing the moon’s pull on the earth. Indicate which parts of the earth would be experiencing a high tide and which would be having a low tide. moon

© ReadyEdPubl i cat i ons •f orr evi ew pur posesonl y• rotation of the earth and moon

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North Pole

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moon’s pull

earth

o c . che e r o t r s r What causes the tides to rise and s fallu allp along coastlines of the world? ethe

(A globe of the world might help you explain your answer.).................................. ............................................................................................................................. .............................................................................................................................

High Time!

To see how much a tide can vary at one place in one day visit this site, which shows some pictures of the coastline of Broome in Western Australia: www.ucmp.berkeley.edu/people/cpm/fall96/Brtides.html Page 46

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The Ocean

Coral

Coral are small marine animals called polyps.

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Visit the following Internet sites to see some wonderful pictures of coral. Print out the pictures. Use your library resources to add to your collection of coral pictures. www.islands.vi/~scubabob/guestphoto_stevepolyps.htm www.uwphotos.com/Pages/CSgallery/csm19.htm www.garyfelton.com/UW10.htm www.reefrelief.org/healthy/healthy_index.html What do you notice about the shape of all the coral in the pictures? ...................

© ReadyEdPubl i cat i ons What features are common to every coral that you viewed? ................................

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What other sea animals do you think coral might be related to? ..........................

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Create a Coral Polyp

Materials: modelling clay or Plasticine paper cups icecream sticks pictures of coral taken from the Internet and other resources

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o c . che e r o t 1. Each person needs a ball ofr clay or Plasticine.

Divide the ball into two smaller s s r u e p balls - one ball about 2/3 in size and the other 1/3 in size.

2. Use the large ball and the paper cup, if required to make a base for the polyp.

(This should be cup-shaped with the base being larger than the bottom.)

3. Use the small ball to make the tentacles and attach to the base.

4. Use the icecream stick, if necessary, to hold the model in place.

5. Once all the coral polyps are complete, they can be joined together to form a coral colony.

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Page 47

The Ocean

Coral Reef

Look up this key word in a dictionary.

• colony ................................................................................................................

A coral reef is formed by the shells of single, small sea animals called coral polyps. As the polyps die, new ones grow on top of the old empty shells. Over time, the collection of shells builds a large rock-like structure called a coral reef.

The top of this reef is covered with new living coral colonies. Coral polyps build a coral reef very slowly and can only grow in clear, shallow, warm ocean water.

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Answer these questions about coral.

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1. What is coral formed from? .............................................................................

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2. Explain the process of coral formation in your own words. Use diagrams. .............................................................................. .............................................................................. ..............................................................................

© ReadyEdPubl i cat i ons •f orr evi ew pur posesonl y• .............................................................................. .............................................................................. ..............................................................................

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There are three types of coral reefs - fringing reefs, barrier reefs and atolls.

Use the following Internet web site or library resources to give a definition of each type. www.seaworld.org/coral_reefs/coralcr.html www.lams.losalamos.k12.nm.us/heacock/HeacockSci/coral.html

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o c . ............................................................................................................................. che e r o barrier ................................................................................................................... t r s super ............................................................................................................................. fringe ....................................................................................................................

atoll ....................................................................................................................... .............................................................................................................................

The Greatest Reef of All The Great Barrier Reef off the coast of Queensland is the world’s largest coral reef.

To view pictures of the reef visit the following Internet site: www.ozramp.net.au/~senani/barrier.htm Page 48

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The Ocean

Oceanic Volcanoes

Find and discuss the meaning of these key words.

continental ............................................................................................................ oceanic.................................................................................................................

Oceanic volcanoes are formed where continental plates meet oceanic plates, or where two oceanic plates meet. There are lots of volcanoes under the sea because it is where the earth’s crust is thinnest and weakest of all. If an oceanic volcano continues to erupt it will form a volcanic island.

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Equipment: hydrogen peroxide dry yeast small glass jar with holes punched in the lid large glass jar or fish bowl (not too wide) safety glasses

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(This should be demonstrated by the teacher or completed under adult supervision.)

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Procedure: 1. Pour enough water into the large jar or fish bowl to cover the small jar by 5 cms.

2. Pour 1/2 cup of hydrogen peroxide into the small jar.

3. Add two teaspoons of yeast into the small jar, stir and cover quickly.

4. Place the small jar, with the pierced lid, into the centre of the fish bowl.

5. Observe the eruption progress.

What happens as the mixture inside the small jar touches the cool water?

. te o ............................................................................................................................. c . c e he r Explain how the experiment relates to the eruption of a real oceanic volcano. o t r s super ............................................................................................................................. .............................................................................................................................

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Record the Island Formation On the back of this sheet record the formation of the volcanic island using labelled diagrams.

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The Ocean

Coral Atoll Islands

Atoll islands are a group of islands, shaped in a horseshoe or ring, which grow over a volcano that has sunk back into the sea. Atoll islands have a large, shallow lagoon in the centre.

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..........................grows and animals like

birds begin to ...................on the island.

The .................................... sinks further into the ocean, until it is no longer visible above the water.

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Complete the description boxes to explain how a coral atoll is formed.

Complete the missing diagrams that demonstrate how an atoll occurs. On a separate piece of paper, glue the matching description and diagram together.

© ReadyEdPubl i cat i ons The .................................... continues tou • f o r r e v i e w p r posesonl y• build up around the volcano forming a

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An .................................. volcano breaks through the ocean floor and .................. sending red-hot ..................into the sky.

The lava hardens as it hits the ocean water.

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shallow ............................. in the centre.

. te o c The ........................ forms a small island . che . e that juts above the ................................ r o t r s super After the.......................................... , the volcano begins to sink slowly back into the ................................................. .

Coral builds and forms a ring around the ................................................ volcano.

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The Ocean

Volcanic Island

Many ocean islands have been formed by volcanic eruptions beneath the sea.

First, ash is blown above the water and then a pile of rock and lava build up until it is above sea level. A volcanic island is formed!

The Birth of an Island Use resources from the library or the following Internet sites to research the birth of the volcanic island, Surtsey.

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www.eyeoniceland.com/photos/contest/co991-96.html www.eyjar.is/eyjar/surtsey.html

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1. When was the volcanic island of Surtsey formed? ..........................................

2. What country is closest to Surtsey? .................................................................

3. Who observed the birth of this volcanic island?...............................................

4. What were the first signs that something strange or unusual was happening?

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5. How long did Surtsey erupt for? .......................................................................

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6. Surtsey has develop some plant life since it was formed.

How do you think this has been possible?

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7. Predict what will happen to the island if it doesn’t erupt again.

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Which Landform?

Which landform is shown in the diagrams.

Give a brief description of how the landform was created.

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Description .....................

Description ...................... Description ....................

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Landform......................... Landform .......................

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Landform ........................

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Description .....................

Description ...................... Description ....................

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Landform ........................

Landform......................... Landform .......................

Description .....................

Description ...................... Description ....................

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Landform......................... Landform .......................

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