Weathering and erosion pack

WORK IN FOURTH YEAR

Abrasion – the effect of erosion on rock, where rock fragments carried by the seas scrape and grind away at a cliff face Arch – a rocky opening through a headland, used to be a cave Attrition – process by which particles of rock being transported by the sea are rounded and gradually reduced in size by being struck against one another Backwash – backward movement of water down the beach after the wave has broken Bar – deposit of sand or silt formed in a river channel, or a long sandy ridge running parallel to coastline. Coastal bars can extend across estuaries to form bay bars Bay – an area of sea between two headlands Beach – material the sea deposits on the coast, can be sand or pebbles

Biological weathering – the breakdown of rocks by plants and animals Cave – an area, which has been hollowed out by the waves at the bottom of a cliff Chemical weathering – the breakdown of rocks by chemical action Cliff – a very steep slope Coastal deposition – laying down or dumping of material by wave action Coastal management – attempts by people to maintain or alter the natural features of the coast to their own advantage Coastline – the line between the land and sea marked by high tide Corrasion/abrasion – caused by large waves hurling beach material against a cliff Corrosion/solution – salts and other acids in seawater slowly dissolve a cliff Deposition – the process of laying down material to form new land Deposition landform – spit, beach etc. Destructive waves – high waves, with strong backwashes, which break frequently causing erosion Dune – mound or ridge of wind-drifted sand Erosion – the process by which rocks are worn away Erosion landform – bay, headland etc. Fetch-the length of water over which the wind has blown which affects the size and strength of waves Fjord – long narrow inlet with high cliff like sides, very deep e.g. Milford Sound in New Zealand

Freeze/thaw – see frost action (physical weathering) Frost action (freeze/thaw) – a form of weathering where water in cracks freezes and expands to split or shatter the rock (physical) Gabions – boulders wired together in a steel mesh box. The stones absorb the wave energy and are prevented from moving by the wire box Groyne – wooden or concrete barrier built at right angles to a beach in order to block the movement of material along the beach by long shore drift. Groynes are usually successful in protecting individual beaches Headland – land that juts out into the sea Hydraulic action – the pounding of a cliff by the weight of water and the effect of air within cracks being compressed and causing intense pressure to weaken a cliff face Landform – a natural feature of the landscape Long shore drift – the current that transports material along the coastline in a zigzag movement Onionskin weathering – the breakdown of rocks by heating and cooling that can cause the surface layers to peel off (physical weathering) Process – the way something happens Revetment – wooden fences built parallel to the sea. The gaps in them allow wave energy to be absorbed, protecting the base of a cliff Rias – long winding inlet with low gently sloping sides e.g. the creek in Dubai Rip rap – large boulders placed together along the base of a cliff, designed to absorb wave energy and protect the cliff from erosion Sea level changes – sea level rises due to melting ice caps, bergs and glaciers

Sea wall – a barrier built behind a beach to protect the coast from the sea Sedimentary rock – a rock formed from material laid down millions of years ago at the bottom of seas and lakes Slumping – the movement of material downhill under the influence of gravity, often associated with rocks becoming saturated Spit – a long ridge of sand and shingle with one end attached to the land and the other end in the open sea Stack – a piece of rock surrounded by sea and left standing away from the coastline Stump – a stack eventually collapses leaving a stump Swash – forward movement of water as the wave breaks on the coast Tombola – spit or ridge of sand or shingle that connects the mainland to an island, e.g. Chesil bank which extends 19km to sea from Dorset Transportation – the movement of material by water, ice or wind Wave – a circular motion of water caused by the wind Wave cut platform – a gently sloping area of flat rocks exposed at low tide Weathering – the breakdown of rocks YOU COULD ADD IGNEOUS, METAMORPHIC, SEDIMENTARY, PERMEABLE, IMPERMEABLE, SLATE, GRANITE, SANDSTONE, BASALT, CHALK, GRAVEL, CLAY, LIMESTONE, MARBLE ETC.

1. ROCKS

8LANDSCAPE WORKSHEET PUPIL’S BOOK PAGES 26–7

What’s in a rock?

Name ________________________________________________________________________________

68 earthworks 1 teacher’s resource book © JOHN MURRAY

The natural landscape is madeup of rocks, and the soil that liesabove them. All the landformsthat you will study are made ofrock. Rocks give us importantclues about how the landscapewas formed – whether they wereforged by heat deep inside theEarth, laid down beneath wateron the sea bed, or changed byintense heat and pressure asmountains were built.

Igneous rockMolten rock deep within the Earth can explode from volcanoes as lava, or force its way into rocks justbelow the surface. Here it cools and turns from liquid into solid crystals made from different minerals.This is igneous rock – a hard, solid, crystalline rock.

Different igneous rocks can be identified by their crystal structure and mineral composition. Themore slowly the rock cooled down at the surface, the larger the crystals tend to be. Granite is acommon igneous rock with large crystals of different minerals, giving it a mottled appearance. Basalt isa dark igneous rock, formed from the cooling lava of volcanoes, with crystals which are too small to beseen without a microscope.

Sedimentary rockSedimentary rocks were originally loose fragments of rock, or dead plants and animals, laid down onthe sea bed. Over millions of years this material, or sediment, was covered by further layers andsqueezed until it turned into solid rock. Sedimentary rock can sometimes be identified, where it isexposed in cliffs, by the layers which may still be visible. The fragments from which it was made canrange in size from the finest particles of clay to large stones.

Sandstone is a common sedimentary rock which is made from sand grains and is often reddish incolour. Limestone is made from the broken shells or skeletons of small sea creatures, making it rich incalcium and often a very light colour.

Metamorphic rockRocks can be changed by intense heat or pressure. Such forces can be found in the Earth’s crust wherevolcanoes erupt or continents collide. The rocks which come into contact with these forces are changedinto a new type of rock. This is metamorphic rock, which is often very hard as a result of the force ithas endured. Metamorphic rocks vary depending on how close they were to the heat or pressure whichformed them. Slate is a dark metamorphic rock formed from sedimentary mudstone or shale. Althoughhard, it has horizontal bands, making it easy to split into flat pieces.

Your task1. Read the information about igneous, sedimentary and metamorphic rocks.

2. Identify samples of granite, basalt, sandstone, limestone and slate, if your school has a collection of rocks.

3. Explain the shape of the coastline in south-west Wales, using this information about the rocks from which it isformed.

New sedimentaryrock forms on seabed

Sea

Metamorphic rockformed by heatand pressure

New igneous rockfrom volcanoes

Layers of oldsedimentary rock

Old igneousrock forms muchof Earth's crust

Hot moltenrock

Earthworks 2 16/8/00 6:33 pm Page 68

Old rocks for new;

1.

2.

3.

Rock Igneous Sedimentary Metamorphic

Slate √

Limestone

Sandstone

Granite

Chalk

Basalt

Marble

Rocks and Relief;

LESSON 1; Look at MyQG or the Internet at

www.open.edu/openlearn/science-maths-technology/science/geology/geology-toolkit Click on Landscape Features in the diagram box. Choose one, e.g. The Giant’s Causeway and produce a poster (A3) with a description, map and pictures

DATE MARKED: GRADE: A B C D MERIT: 1 2 ORDER MARK: DETENTION: COMMENT: TARGET:

2. WEATHERING

Weathering, rivers and coasts NEW KEY GEOGRAPHY Connections pages 6–7

Weathering

1.1

NEW KEY GEOGRAPHY Connections Teacher’s Resource © Nelson Thornes 200623

�1 Read the statements listed below. Use them as labels, drawing arrows

to show where they belong in the illustration.

�2 Categorise the labels by colouring them as follows:

� Red for chemical weathering.

� Green for biological weathering.

� Blue for freeze–thaw weathering.

�3 How can the building be protected against each type of weathering?

�4 Which side of your home do you think suffers the most from weathering?

Explain your answer.

Everything around us is slowly falling to pieces. Buildings, monuments,

roads, coasts and mountains are all crumbling away. They are being

attacked and broken up by the action of rain, sun, frost and even plants

and animals. We call this weathering.

A Water freezes and can crack roof tiles.

B Drainpipes may rust and leak.

C Rainwater contains small amounts of acid.

D Mosses and plants can make holes in roof felt.

E Insects may burrow into roof timbers leading

to rotting.

F Sunlight and wind will dry and crack paintwork.

G Rainwater can soak into wooden window

frames leading to rotting.

H Wind may blow off roof tiles.

I Rain can get into gaps between bricks and

dissolves mortar.

J Tree roots and rotting plant roots may

weaken house foundations.

K Warmth speeds up chemical changes.

Weathering, rivers and coasts NEW KEY GEOGRAPHY Connections pages 6–7

What causes weathering?

1.2

NEW KEY GEOGRAPHY Connections Teacher’s Resource © Nelson Thornes 200624

Weathering is the breakdown of rocks by water, frost and temperature

change. The effects of plants and animals can also break rocks down.

�1 Study the table below. For each cause of weathering, tick whether

you think it is very likely, possible or unlikely to happen around

your school.

�2 Using a copy of the table above, carry out a brief survey of your

school to discover any examples of weathering.

�3 Present your findings in a short written report with the title:

‘Our school is falling to pieces!’ In your report you should use ICT,

maps, sketches and (if possible) photos.

Causes of weathering Very likely Possible Unlikely

Seeds blow into cracks in walls.

Plant and tree roots force cracks to widen.

Water freezes and can crack roof tiles.

Acid in rainwater causes brickwork to rot and crumble.

Wind may blow off roof tiles.

Warmth speeds up chemical changes.

Rainwater can soak into wooden window frames leading to rotting.

Stone is worn away or pitted.

Concrete is repeatedly heated and cooled.

Moist air helps chemical reactions.

Sunlight and wind may dry and crack paintwork.

Heated walls expand at different rates.

Ice crystals expand and help push cracks apart.

Rotting plants corrode brickwork.

Tree roots may weaken school foundations.

REMEMBER TITLE AND DATE LESSON 1

LESSON 2; Test your Skills;

www.learner.org/interactives/rockcycle/testskills.html Print out the score and stick it in your packs

DATE MARKED: GRADE: A B C D MERIT: 1 2 ORDER MARK: DETENTION: COMMENT: TARGET:

3. EROSION

REMEMBER TITLE AND DATE LESSON 1

Weathering, rivers and coasts NEW KEY GEOGRAPHY Connections pages 8–9

How can erosion help shape the land?

1.4

Weathering and erosion work together. Erosion is the wearing away of rock

and its removal by streams, ice, waves and wind. Erosion, transportation and

deposition help shape the land.

�2 Which kind of erosion do you think has been most important

in shaping the land in the UK? Explain your answer.

NEW KEY GEOGRAPHY Connections Teacher’s Resource © Nelson Thornes 200626

�1 In the diagrams below, use arrows to join the three things

to do with erosion by:

� ice in blue

� rivers in green

� the wind in red

� the sea in yellow.

Water moving in riverserodes valleys byremoving tiny bits of rockfrom bed and banks.

Waves at sea smash intocliffs and break off rockparticles, which are brokenup into sand.

In deserts, the windcarries tiny grains of sandand blasts them intorocks, eroding them intostrange shapes.

In high mountains, icecollects and moves downvalleys as glaciers,grinding away the rock asit travels.

Valley wornaway in hills.

Rocks worninto strangeshapes.

Cliffs wornaway.

Deep,straightvalley in themountains.

How can erosion help shape the land?

LESSON 3; Pack p35/6; How can erosion help shape the land? DATE MARKED: GRADE: A B C D MERIT: 1 2 ORDER MARK: DETENTION: COMMENT: TARGET:

Weathering, rivers and coasts NEW KEY GEOGRAPHY Connections pages 8–91.5How does erosion shape the land?Read the model answer below. It has been written to answer activity 3 on

page 9 of the pupil book. Use it to mark either your own answer or the

answer of one of your classmates.

NEW KEY GEOGRAPHY Connections Teacher’s Resource © Nelson Thornes 200627

A

� Rivers wear away the bed and banks of the channel constantly.

� The material is transported downstream by the water.

� Material is deposited when the water slows down.

� Extension: During a flood large boulders can be eroded and transported downstream.

� Waves attack the coast all of the time.

� Rock at the coast is weakened by the waves and pieces break off.

� Currents transport material away and deposit it elsewhere on the coast.

� Extension: During a storm each wave has a weight of several tonnes.

� A glacier is a tongue of ice which moves down the valley.

� Stones and boulders frozen into the ice act like sandpaper on the rock beneath the glacier.

� As the glacier moves, it transports material down the valley.

� Extension: Glaciers erode both the sides and bottom of a valley.

� Wind picks up tiny particles of sand.

� The wind uses these particles to erode anything that gets in itsway.

� The wind also transports particles of eroded material for manymiles.

� Extension: The wind erodes rock in the desert into strange shapesby sandblasting.

Type Description

4. COASTS;

a). WAVES

b). EROSION,

c). TRANSPORTATION,

d). DEPOSITION,

e). REVIEW

4a. WAVES

4b.

COASTAL

EROSION

7LANDSCAPE WORKSHEET PUPIL’S BOOK PAGES 24–5

How do cliffs erode?

Name ________________________________________________________________________________

© JOHN MURRAY earthworks 1 teacher’s resource book 67

Your task1. Look at the drawings below. They show how the sea erodes cliffs.

The top three drawings show how the sea erodes cliffs made of hardrock, such as limestone.The bottom three drawings show how the sea erodes cliffs made of softrock, such as clay.

2. Write sentences to describe what is happening, in the space below eachdrawing. Use the labels in your sentences.

Hard rock forms vertical cliff

Highwaterlevel

Notch cutby waves incliff

Low water level

Cliff now overhangs cave

Cave formedby waveseroding cliff

Wave cut platform

New cliff formed as coastlineretreats

Rocks leftby cliff fall

Soft rock forms slopingcliff

Rainfall seepsinto rock

High water level

Low waterlevel

Cliff top begins to fall

Landslip wherewater helps rockto slide down

New cliff formed ascoastline retreats

Sea washes soft material away

Earthworks 2 16/8/00 6:33 pm Page 67

LESSON 5; 1). Pack p54; How does the sea shape the coast? 2). Pack p55; Coastline erosion 3). Pack p56; How do cliffs erode?

DATE MARKED: GRADE: A B C D MERIT: 1 2 ORDER MARK: DETENTION: COMMENT: TARGET:

9LANDSCAPE WORKSHEET PUPIL’S BOOK PAGES 26–7

What is happening at Flamborough Head?

Name ________________________________________________________________________________

© JOHN MURRAY earthworks 1 teacher’s resource book 69

Your task1. Label each of the landforms around Flamborough Head, shown in the

sketches below, with the correct label – arch, cave, stack.

2. Compare the three sketches with Diagram E on page 27 in the Pupil’s Book. Number them in the correct order.Complete the passage below, to describe how Flamborough Head has been eroded. Use the words from the box.

Flamborough Head is a ____________________ which juts out into

the North Sea. ____________________ from the sea attack the rock

with great ____________________. As each wave hits the cliff, air is

_________________ into the cracks in the rock. The pressure

________________ the rock so the cracks __________________.

Gradually, the base of the ____________________ is eroded and a

large _________________ forms which is a cave. When the sea wears

right through the headland the cave becomes an _______________.

The rock above the arch is ________________ by frost and rain.

Eventually it may ____________________, leaving a

____________________ of rock standing alone in the sea. This is called a stack.

shatters arch compressed waves collapse pillar cliff widen hollowweathered force headland

Earthworks 2 16/8/00 6:33 pm Page 69

4c. COASTAL

TRANSPORTATION

17LANDSCAPE WORKSHEET PUPIL’S BOOK PAGES 33–5

Longshore drift

Name ________________________________________________________________________________

© JOHN MURRAY earthworks 1 teacher’s resource book 77

Your task1. Look at the three diagrams below. They show how the process of

longshore drift works. Write your own description of longshore drift in the space provided.

2. Look at the map of the Dorset coast below. Draw an arrow to show the direction of longshoredrift along the coast. Explain what effect groynes on the beach atBournemouth could have on other parts of thecoast.

___________________________________________

___________________________________________

___________________________________________

___________________________________________

___________________________________________

___________________________________________

___________________________________________

___________________________________________

___________________________________________

___________________________________________

____________________________________________

____________________________________________

____________________________________________

____________________________________________

_________________________________________________________________________________________

________________________________________________________________________________________

_________________________________________________________________________________________

________________________________________________________________________________________

_________________________________________________________________________________________

DORSET

Lyme Bay

ChesilBeach0 10 km

Weymouth

Portland Bill

Swanage

Bournemouth

Poole BayChristchurch

Bay Isle of Wight

Beach

KeyScale

Wind direction

Water runningdown the beach

Beach

Sea

Wave direction

Beach

Sea

Earthworks 2 16/8/00 6:33 pm Page 77

LESSON 6; Pack pages 63, 64 and 65; longshore drift

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4d. COASTAL

DEPOSITION

REMEMBER TITLE AND DATE LESSON 1

REMEMBER TITLE AND DATE LESSON 1

LESSON 8; Find an example of a spit, bar and

tombolo; name, location and picture DATE MARKED: GRADE: A B C D MERIT: 1 2 ORDER MARK: DETENTION: COMMENT: TARGET:

4e. REVIEW

Review;

Weathering, rivers and coasts NEW KEY GEOGRAPHY Connections pages 16–17

How does the sea shape the coast?

1.13

NEW KEY GEOGRAPHY Connections Teacher’s Resource © Nelson Thornes 200636

The coastline is always changing its shape. Some parts

are being worn away by erosion while other parts are

being built up by deposition.

�1 a Cut out the dominoes below and study the key

words written on them.

b Working in pairs, lay all the dominoes in a

straight line.

c Now arrange the dominoes in the correct

order. You may only put a domino in place if

you can explain to your partner the link

between the words that you are putting

together. There is only one correct order!

�2 Stick the dominoes in your book or file in the

correct order.

START Bangladesh

Wearing awaythe land byrivers, sea,ice or wind

SPIT

START BangladeshAn openingthrough a

rock

LONGSHOREDRIFT

START Bangladesh

An area ofland that jutsout into the

sea and usuallyends in a cliff

ARCH START Bangladesh

Movement oferoded

material byrivers, sea, ice

or wind

FINISH

START Bangladesh

Current whichcarries

material alongthe beach

DEPOSITION START Bangladesh

Laying downof materialcarried by

rivers, sea, iceor wind

BEACH

START Bangladesh

Formed whencracks in the

rock arewidened by

erosion of thesea

BAY

START BangladeshA wide

curved inletof the sea

STACK START BangladeshArea of sandor pebbles,

along a coastCURRENT START BangladeshSTART EROSION

START BangladeshFlow of waterin a certaindirection

START Bangladesh

Long, narrowtongue of sand

and shinglewhich growsout from the

shoreline

CAVESTART Bangladesh

A pillar of rockon the sea

coastseparated fromthe mainlandby erosion

HEADLANDTRANSPORTATION

NEW KEY GEOGRAPHY Connections Teacher’s Resource © Nelson Thornes 200638

Weathering, rivers and coasts NEW KEY GEOGRAPHY Connections pages 16–17

How the sea shapes the coast

1.15a

The sea is still. The movement of

the air changes the shape of the

coast all of the time.

Storm waves crash against the

coast eroding it away and creating

depositional landforms along the

coast. Waves gather and move

material from one place to another,

which is a process called erosion.

Storm waves deposit material

creating depositional landforms.

Erosional landforms are caused by

water alone that wear away the

coast. This bombardment under-

cuts the cliff causing caves to form

which expand to make cracks.

When the caves erode right

through a bay, an arch is formed.

Further erosion causes the arch to

collapse leaving a pillar of rock

standing out in the sea, which is

known as a pillar.

Soft rock at the coast erodes slowly

and can be seen at the coast as a

large piece of land jutting out into

the sea called a headland. Soft rock

at the coast is eroded away very

slowly. Where this happens a bay is

formed.

Beaches and stacks are both types

of depositional landform that can

be found at the coast. Both are

created by waves that transport and

erode eroded material to create a

build-up of sediment at the coast.

It’s the sea’s ability to erode, move

and deposit material along the

coast that creates the many

interesting and changing landforms

that you find at the coast.

A

Explanation Correction

Beth was asked to write an explanation of how

the sea shapes the land. There are 15 mistakes in

Beth’s homework. Each mistake is underlined. For

each mistake, write an explanation of why it is

incorrect and write the correct answer in the

columns alongside.

Name of landform

Written definition Sketch to show its appearance

arch Rocky opening through

a headland

cave

beach

cliff

headland

stack

Wave-cut platform

Review, answers to pack p19;

5. COASTAL

PROTECTION/

MANAGEMENT

Mappleton;

19LANDSCAPE WORKSHEET PUPIL’S BOOK PAGES 38–9

The cost of coastal protection

Name ________________________________________________________________________________

© JOHN MURRAY earthworks 1 teacher’s resource book 79

Your task1. Read about different methods of protecting the coast on page 38 of

the Pupil’s Book.

2. Work out the cost of protecting 60 km of the Holderness coast, using the prices below. Write your answers into the table.a) sea wall: £7,000 per metreb) revetments: £1,000 per metrec) rock groynes: £1,500,000 per groyne (200 m apart)d) beach feeding: £1,000 per metre

3. Think about the advantages and disadvantages of each method, including the cost.Complete the table below. List advantages and disadvantages in the correct spaces.

Which method/methods of coastal protection would you choose? ________________________________________

_____________________________________________________________________________________________

Give your reasons: ______________________________________________________________________________

_____________________________________________________________________________________________

_____________________________________________________________________________________________

_____________________________________________________________________________________________

_____________________________________________________________________________________________

Method Cost Advantages Disadvantages

sea wall per km =_________________

per 60 km =_________________

revetments per km =_________________

per 60 km =_________________

rock groynes per km =_________________

per 60 km =_________________

beach feeding per km =_________________

per 60 km =_________________

Earthworks 2 16/8/00 6:33 pm Page 79

REMEMBER TITLE AND DATE LESSON 1

LESSON 9; Find 5 pictures of examples of coastal protection and give the advantages, disadvantages and cost of each

DATE MARKED: GRADE: A B C D MERIT: 1 2 ORDER MARK: DETENTION: COMMENT: TARGET:

21LANDSCAPE WORKSHEET PUPIL’S BOOK PAGE 39

Should the coastline be saved?

Name ________________________________________________________________________________

© JOHN MURRAY earthworks 1 teacher’s resource book 81

COASTAL CHRONICLE

SHOULD THE COASTLINE BE SAVED?

Stick map here.

Write your explanation here.

Stick drawings or diagrams here.

Write your views here.Write geographer’s views here.

Write farmer’s views here.

‘NOBODY SEEMS TO CARE!’Interview with a farmer

‘THE SEA WILL ALWAYS WIN’Interview with a geographer

WHY IS THE COAST DISAPPEARING?

WHAT CAN BE DONE?

THE ‘CHRONICLE’ SAYS –

Earthworks 2 16/8/00 6:34 pm Page 81

REMEMBER TITLE AND DATE LESSON 1

11LANDSCAPE WORKSHEET PUPIL’S BOOK PAGES 28–9

The mystery of Holbeck Hall

Name ________________________________________________________________________________

© JOHN MURRAY earthworks 1 teacher’s resource book 71

Joan Turner, owner ofHolbeck Hall

Michael Clements, Directorof Technical Services forScarborough Council

James Keld, who lives nearHolbeck Hall

Deirdre Clutterbuck,geologist at Hull University

Your taskUse this sheet to help you role play the part of people in Scarborough, for Activity 3 on page 29 of the Pupil’s Book.

My family bought the Holbeck Hall Hotel in 1978. It was originally built in 1887 as ahome for a wealthy family. It had been converted into a hotel in 1930. We hadabsolutely no idea that it was in any danger from the sea. If we had known, it is veryunlikely that we would have bought it.

It was a delightful hotel, full of charm and character. It was built in mock Tudorstyle with large timber-framed gables and stood, amidst rose gardens and largeimmaculate lawns, looking out over the sea. We had almost no warning that the hotelwas about to collapse. In the early hours of the morning on 4th June 1993 there wasa huge landslip in the garden, when part of the lawn fell about 4 metres. We took theguests out of the hotel as quickly as we could. Within 24 hours it was gone.

My family has lived in Scarborough for generations. Over the years there have beenoccasional cliff falls but none as dramatic as this one. The strange thing is that thesea wall was built to protect the cliff, so this came as a complete surprise.

We moved to this part of town because it is quiet and the houses are larger. Wedidn’t expect anything like this to happen. We want the council to reassure us thatthey are doing everything possible to prevent another cliff collapse. Otherwise wewould want to move somewhere else. The trouble is, who would want to buy a house ifthey thought it might fall into the sea?

The cliff collapse which led to the loss of Holbeck Hall was due to a landslip in theclay from which the cliffs are made. Water had collected in the clay and made iteasier for the rock to slide down under the force of gravity. We plan to keep the areaclosed to the public until we are sure that it is safe.

It is very unlikely that any other properties in the area are going to be affected.In the long term we will stabilise the cliffs by making drains to take the water awayfrom the cliff top. We will also strengthen the base of the cliff with large rocks thatwill absorb the energy of the waves. I don’t believe that the cliff will collapse again.

In my opinion, it is only a matter of time before many places along the east coastof England disappear into the sea. We may be able to protect some areas for a bitlonger by building sea walls and draining the cliffs to stop them collapsing. Butwithin the next hundred years the sea level is going to rise and either we build higherand higher sea defences or we must allow nature to take its course. I think that weneed to start planning for the future now. We should stop any more building in areasthat are likely to disappear. People who live there now could be given compensationso that they could afford to move.

Earthworks 2 16/8/00 6:33 pm Page 71

Weathering, rivers and coasts NEW KEY GEOGRAPHY Connections pages 20–21

How can coastal erosion be reduced?

1.19

NEW KEY GEOGRAPHY Connections Teacher’s Resource © Nelson Thornes 200643

Protecting coasts is not easy. There are arguments for and against trying to

protect the coastline from erosion.

�1 Attempts to protect the coastline involve engineering.

Read this list of coastal protection schemes and complete

a copy of the table below. It has been started for you.

�2 Some people think that one policy for coastal protection is to do nothing!

They believe that nature will take its course despite coastal defences.

Do you agree with this policy? Would you agree with the policy if you lived

in a coastal home? Explain your answer.

Sea wall: Made with stone or concrete.May be curved at the top to divert theforce of the waves back out to sea, butcan be undermined by waves. Usualdesign life is 50–75 years. It costs£5,000 per metre to build.

Groynes: A long, low wall built outinto the sea at right angles to thebeach. Many of them have to be builton one beach several hundred metresapart. The aim is to prevent the lossof precious beach sands throughlongshore drift. Concrete groynes cancost £200,000 each. They help widenbeaches and protect cliffs. Woodengroynes are much cheaper, but theyrot and may be damaged by storms.

Rock armour: A collectionof large interlockingboulders sometimes fixedinto position to protect thecoast by disrupting thewaves. It costs £3,000per metre to build.

Revetment: Gently slopingconcrete wall that allowswaves to run up it, thereforereducing their energy. It costs£2,000 per metre to build.

Offshore breakwater: A concretewall or interlocking boulders built alittle way out from the shoreprotects the coastline by disruptingwave energy and creating an area ofcalm water inshore. It is ugly, candisrupt the marine ecosystem andcosts over £3 million per km.

Stone gabions: Strong steelcages filled with rocks andsome sand allowing grassesto grow. The cost to buildis £200 per metre but theyare ugly constructions.

Beach rebuilding: Sandremoved by longshore drift isreplaced artificially every year.This gives a more naturalappearance, but is expensive –£300,000 per km per year.

Wooden revetments: Slattedframe that decreases waveenergy. The cost to build is£500 per metre, but thatdoes not include repairs.

Coastal defence scheme Approximate cost Possible effects

Coastal protection methods

Sea wall made withstone or concrete.

£5,000 per metre.

How can coastal erosion be reduced?

COASTAL EROSION: SELF ASSESSMENT

Assessing 360° Checklists from Skills Workbook 1 © Heinemann 2004, geography 360° Teacher’s Handbook 1

Understand and know

Need more practice and revision

Do not understand

I can define and give examples of the three ways that rocks are formed

I can explain how rock types can affect the development of landforms

I can define weathering and erosion and give examples

I can describe how different types of weathering and erosion happen

I know how freeze-thaw works

I can explain how waves are formed and what fetch is

I can explain the difference between constructive and destructive waves

I understand how waves erode

I can name at least five coastal landforms resulting from weathering and erosion

I can describe the causes and effects of cliff erosion and collapse

I can explain the process of long shore drift

I can name at least two landforms of deposition

I know what groynes are and why they are built

I can give examples of ways to protect the coastline

What I enjoyed doing most

What I found most difficult

CHANGING LANDSCAPES AND COASTS HOMEWORK

Lesson 1; Look at MyQG or the Internet at

www.open.edu/openlearn/science-maths- technology/science/geology/geology-toolkit Click on Landscape Features in the diagram box. Choose one, e.g. The Giant’s Causeway and produce a poster (A3) with a description, map and pictures

Lesson 2; Test your Skills; www.learner.org/interactives/rockcycle/testskills.html Print out the score and stick it in your packs

Lesson 3; Pack p35/6; How can erosion help shape the land?

Lesson 4; Revision; waves

Lesson 5; 1). Pack p54; How does the sea shape the coast? 2). Pack p55; Coastline erosion 3). Pack p56; How do cliffs erode?

Lesson 6; Pack pages 63, 64 and 65; longshore drift

Lesson 7; BBC information and animations; http://www.bbc.co.uk/schools/riversandcoasts/coasts/change_coast/index.shtml

and Revise for exam; look in coastal processes review folder on MyQG for notes etc. that are VERY useful.

Lesson 8; Find an example of a spit, bar and tombolo; name, location and picture

Lesson 9; Find 5 pictures of examples of coastal protection and give

the advantages, disadvantages and cost of each

Extra extension work/independent learning; Doddle -browse in all resources for energy and resources; https://www.doddlelearn.co.uk

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