GEOGRAPHY GCSE :

COASTS UNIT

COASTS : Areas to revise / Areas you can expect Exam Questions on.Weathering and Erosion are important physical processes in coastal areas.

Describe and explain the processes of weathering and erosion that change coasts (FLAMBOROUGH HEAD, MAPPLETON)

Physical processes, rock type and structure all give rise to distinctive coastal landforms

Use examples to explore the landforms associated with ‘hard’ coastlines including headland, bays, caves, arches, stacks, wave-cut platforms (FLAMBOROUGH HEAD), and ‘soft’ coastlines including slumping & landslides (MAPPLETON, TUNSTALL)

The movement and deposition of beach material creates distinctive landforms

Use examples to explore the processes of longshore drift and the formation of beaches, bars and spits (MAPPLETON, HORNSEA, WITHERNESEA, SPURN HEAD)

Some areas are protected from the effects of coastal erosion

Use examples of Shoreline Management Plans to show why some coasts are protected rather than others, and how decisions are made to protect some coasts (HOLDERNESS)

There are different methods that can be used to protect coasts from erosion.

Know the difference between ‘hard’ and ‘soft’ engineering strategies. Use examples to show how ‘hard’ engineering works (sea walls, rock armour/rip-rap, gabions, tetrapods, groynes, cliff drainage. (WITHERNSEA, HORNSEA, MAPPLETON, EASINGTON, JAPAN)

Some coastal areas are protected by environmental management

Use an example to show the environmental value of some coastal landscapes, and the strategies used to protect these valuable coastal environments. (SPURN HEAD, GREEK ISLANDS – TURTLES, GREAT BARRIER REEF)

Coastal areas are multi-use areas which provide opportunities for a number of human activities

Describe and explain the reasons for the growth of population in coastal areas. (TOKYO – JAPAN, ISLE OF WIGHT, HUMBER ESTUARY & EAST YORKSHIRE COAST)

Use an example to show the range of human activities to be found in coastal areas and explain why they are attracted to the coast. (HUMBER ESTUARY)

Coastal areas can be Growth Poles for economic growth

Use an example to show the coast is an important location which encourages economic development. (DUBAI, BELIZE CARIBBEAN RIVIERA)

There are frequently conflicts of interest at the coast and this creates a need for management strategies to solve the issues

Use examples to examine issues arising out of conflicts of interest between economic development and the need for conservation in coastal areas. Give examples of solutions to protect coastal areas (HUMBER, TURTLES & GREEK ISLAND, GREAT BARRIER REEF – AUSTRALIA)

The sustainable future of coasts needs the whole of the coast to be managed as a system

Use an example of Integrated Coastal Zone Management to explore the various pressures on the coastal environment and the strategies being used to ensure the long-term sustainability of the area (NE COAST OF AUSTRALIA – GREAT BARRIER REEF)

Protecting coastal areas from the increasing risk of erosion and flooding will require the best long-term management of the coast.

Use an example of Managed Coastal retreat to describe how it operates, explain how it helps protect the coast, and evaluate how effective it is in dealing with coastal flooding when taking the advantages & disadvantages into account. (MANAGED RETREAT ON THE HUMBER N. BANK)

Examine how monitoring and planning might be used to manage the threat of sea level rise (RESPONSE PLAN, N. YORKSHIRE COAST – ROBIN HOODS BAY V REIGHTON BAY

Key Factors for Scoring well in Geography at GCSE 1 BREADTH of points : giving MORE THAN ONE point, fact, reason or explanation for the thing you are writing about. (eg giving 3 ways by which coastal cliffs are eroded by the sea—not just one process). 2 LINKING points : showing how one thing leads to another, which leads to another...and so on. (eg more tourists going on holiday to Greek islands —> heavy use of beaches —> sea turtles frightened off from laying eggs on beach —> breeding numbers go down —> fewer turtles in the Mediterranean Sea.) 3. EXAMPLES : using case-studies to support what you are writing. These are real places you have studied which you should use as evidence to back up your statements. When a question asks you for ‘an example’ - it means ‘name a real place and give some exact details about it.’ (eg Coastal defences can also cause problems as well as bring benefits. For example at Mappleton on the coast in East Yorkshire, the stone groynes built to build up the beach to protect the village has caused even faster erosion a few miles further south along the Holderness coast where the beach is not so wide now.) 4. Using GEOGRAPHICAL TERMS : specialist words like ‘corrasion’, ‘deposition’, ‘abrasion’ , ‘spit’, ‘shoreline management plan’, ‘Response Plan’ 5. STRUCTURING the answer : dividing your longer answers into distinct sections : ‘Advantages’ versus ‘Disadvantages’ ; ‘Short-term effects of erosion then ‘Long-term effects of erosion ; ‘Economic benefits of tourism’ then ‘Social’ - and ‘Environmental benefits of tourism’ …..and then the ‘problems’ under the same headings; ‘Physical’ attractions of a coastal resort then the ‘Human’ attractions. 6. Most important of all : ANSWERING THE QUESTION - doing what the Command words in the ques-tion tell you to do (‘Describe’ ‘Explain’ ‘Compare’ …… ‘for a feature of coastal deposition you have stud-ied’……. Give the information that is asked for—don’t write about features of ‘erosion’!! ) And aim to fill the space that has been given to write in— give enough information to be able to get the number of marks on offer. ((3) marks—make 3 points. (8) Marks………. Write quite a lot, structure it into sections, and provide examples/case-studies.

Coasts : Features of Erosion / Headlands and Bays

Key Terms :

Headland Bay Resistant Rock

Less resistant rock Erosion

Peninsula (headland surrounded on 3 sides by water)

Example / Case-Study :

Flamborough Head (Headland)

Bridlington Bay

Holderness coast (Bay)

Possible Questions :

Describe different features of erosion at the coast

Why do some areas of coastline jut out more than others?

Where 2 or more different types of rock exist at the coast, it is likely that one is more resistant than the other to erosion by the sea. The less resistant rock is eroded more quickly, leading to BAYS. The more resistant rock is eroded – but more slowly, leaving it as a HEADLAND

Weblinks :

Watch this BBC video clip on Headlands and Bays

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Coasts : Features of Erosion / Headland and Bays

Key Terms :

Chalk (more resistant rock)

Boulder clay (less resistant)

Ice-sheets

Coastal retreat

Example / Case-Study :

Flamborough Head (Headland)

Holderness coast (Bay)

Lost village ‘Owthorne’ – east of Withernsea

Possible Questions :

Describe the effects of coastal erosion.

What are the impacts of coastal erosion on human activity?

In East Yorkshire the more resistant rock is the CHALK which is in the North of the coast and forms the HEADLAND of Flamborough Head

The less resistant rock is not really a ‘rock’ at all, but the deposits from the last advance of the Ice-sheets in the last ICE-AGE. As the ice-sheets melted, they deposited the clay and boulders they carried inside them. Holderness is made up of much less resistant BOULDER CLAY which forms one of the fastest eroding coasts in the world at over 3m a year.

As a result of the rapid erosion of the Boulder Clay, over 2 miles of coast has been worn away since Roman times leading to the loss of much farmland and many villages.

Weblinks :

http://www.fortunecity.com/greenfield/ecolodge/25/erosion.htm

Watch this BBC video clip on Holderness boulder clay

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Coasts : Features of Erosion / Joints, Caves, Arches, Stacks, Stumps, Wave Cut Platform

Key Terms :

Joint Cave Arch Stack

Stump Wave-Cut Platform.

EROSION PROCESSES :

CORRASION (ABRASION)

CORROSION (Solution)

HYDRAULIC ACTION

FREEZE-THAW ACTION

UNDERCUTTING

Example / Case-Study :

Flamborough Head

The chalk stack at Selwicks Bay is called ADAM

Possible Questions :

Describe and explain features of coastal erosion.

What processes take place at the coast to give distinctive landscape features?

At Flamborough Head there are distinctive FEATURES of EROSION. These show the headland is being slowly eroded. They also provide attractions for tourists who want to explore the caves, rock pools and arches. Sea birds nest in the joints on the cliff faces and bats may nest in the roof of caves. But they can be hazardous with rock falls from the cliffs, people slipping on the wave-cut platform, and ships running aground on Stumps at high tide

Weblinks :

http://www.geography.learnontheinternet.co.uk/topics/flamborough.html

Watch this BBC video clip on Stacks

Or this BBC video clip on Stacks

1. The process starts with a small JOINT – a weakness in the rock which forms a crack. Chalk has many joints as it is not a particularly strong rock

2. The Joint is enlarged (made bigger) into a CAVE. The sea does this through HYDRAULIC ACTION, and CORROSION (Solution).

3. If the cave is one side of a Headland, it may ERODE through to the other side to form an ARCH.

4. The roof of the Arch is above the direct action of waves, but may get thinner due to sea-spray dissolving the rock due to CHEMICAL ACTION (corrosion) and from FREEZE-THAW action in winter when water enters small joints and expands when it freezes, widening the joints

5. Once the roof of the Arch is too thin to support itself it may collapse leaving a STACK. This pillar of rock is eroded at the top by Corrosion and Freeze-Thaw action, and at its base by CORRASION (also called ABRASION) when rocks are smashed against the rock face by storm waves causing UNDERCUTTING.6. The Stack is

worn down to leave a STUMP which just emerges at low tide.

7. Eventually the Stump is worn down to leave a rock platform where the cliff used to be – known as a WAVE-CUT PLATFORM full of rock pools and uncovered at low tide

3

A

B

C

D

E

F

G

JOINT

STUMP

STACKARCH

LARGE CAVE

SMALL CAVE

WAVE-CUT PLATFORM

Coasts : Features of Erosion / Joints, Caves, Arches, Stacks, Stumps, Wave Cut Platform 4

Coasts : Processes of Erosion / How the sea wears away ‘Hard’ Coasts

Key Terms :

Weathering Erosion

Corrasion (abrasion)

Hydraulic action Attrition

Corrosion (solution/chemical action)

Freeze-thaw action

Example / Case-Study :

Flamborough Head (Headland)

Possible Questions :

Distinguish between ‘weathering’ and ‘erosion’ at the coast.

Which of the following processes are ‘erosion’ and which are ‘weathering’?

Weathering : how rock is broken up and disintegrates, ready to be removed by waves.

Erosion : rock is worn away and transported away at the same time

Weathering ErosionFreeze-Thaw action

Where water (from rain or sea spray) enters joints above the water level, freezes on a cold night, ice expands and makes the joint wider

Corrasion (Abrasion)

Where chunks of rock are flung into cliffs by storm waves chipping bits off the cliff

Corrosion (solution / chemical action)

Where acids and salts in sea-water or sea-spray cause rocks to dissolve or disintegrate.

Hydraulic Action

Where air is compressed into a joint as a wave breaks against a cliff, then expands explosively as the wave recedes – vibrating the rock, making joints wider

Attrition

When rocks and pebbles on the shore wear each other down and smooth off rough edges as they roll against each other as waves roll them

Weblinks:

Watch this BBC video clip on Weathering

Watch this BBC video clip on Erosion

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Corrasion (Abrasion)Where cliff faces are worn away by rocks hitting them by the force of waves.

CorrosionWhen salts and other acids in seawater slowly dissolve the chalk (also known as solution)

Hydraulic ActionWhen storm waves crash against a cliff, they compress air into joints in the rock. As the wave recedes the air is released with explosive force. This vibrates the cliff, makes joints bigger, and breaks bits of rock away.

Coasts : Processes of Erosion / next 2 slides – which is ‘weathering’ and which ‘erosion’? 6

AttritionWhere the rocks wear against each other as they roll over each other by the waves - making them smoother and smaller

Freeze-thaw actionWater (rain or wave spray) seeps into cracks in the rocks, freezes on cold nights and expands. This force the joint apart. Over many years chunks of rock will be broken off.

Chemical actionRain is a weak acid – and will dissolve chalk easily as it falls on the exposed roof of the arch. Along with the salt sea spray this dissolves the roof

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Coasts : Features of Erosion / ‘Soft’ Coastline erosion – Holderness Boulder clay

Key Terms :

Saturated Boulder Clay

Lubricated Slip plane

Slumping

Notch

Undercutting

Example / Case-Study :

Holderness Coast East Yorkshire

Tunstall,

Aldbrough,

South of Mappleton

South of Withernsea

Possible Questions :

What are the different ways in which coasts are eroded?

How is erosion of a Soft cliff different from a Hard cliff?

The less resistant BOULDER CLAY of Holderness is removed from below, but made ready for erosion from above.

Rain soaks into the heavy clay and does 2 things:

a) Rainwater makes the clay even heavier and likely to slump

b) Rainwater lubricates any weaknesses in the boulder clay forming a SLIP PLANE which front portions of cliff SLUMP down.

At high tide crashing waves wear away the cliff at the base from CORRASION/ABRASION forming a NOTCH which leads to UNDERCUTTING. The front of the cliff is then unsupported and the weight of saturated clay slides down onto the beach – known a SLUMPING. The sea has to remove this fallen material before it can start eroding the next new section of cliff face – but this doesn’t take more than a few high tides to do

Weblinks :

http://www.stacey.peak-media.co.uk/holderness/holderness.htm

Watch this BBC video clip on Slumping

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Coasts : Features of Erosion / ‘Soft’ Coastline erosion – Human consequences

Key Terms :

Coastal protection

Environmental impact

Economic impact

Social impact

Political impact

Example / Case-Study :

Holderness Coast East Yorkshire

Tunstall,

Aldbrough,

South of Mappleton

South of Withernsea

Possible Questions :

What are the human consequences of coastal erosion?

What arguments are put forward for protecting coasts from erosion?

The fact that boulder clay is not solid rock – but deposits from the ice-sheets of the last glaciation, means than it is relatively quickly eroded – on average about 2-4 m is eroded each year where there is no coastal protection, but in winters with particularly strong on-shore winds pushing powerful storm waves, it can be up to 12m.

The consequences are:

Environmental Impact : Loss of agricultural land. Holderness is Grade 2 arable (wheat/barley) land. (2nd best of 5 grades)

Economic Impact: Loss of tourist facilities such as caravan sites. Owners have to buy or rent fields further inland and move caravans away from the cliff edges

Social Impact : Residents lose gardens and eventually have to move out of their homes. They get no compensation and no-one will buy them. They have to pay to have their homes demolished as they can’t let them collapse onto the beach below.

Political Impact : local councillors have to decide if they are going to pay for coastal protection and cliff defences – or let the coast erode with the loss of roads, farms & villages

Weblinks

http://news.bbc.co.uk/1/hi/england/humber/7103504.stm

Watch this BBC video clip on Holderness

Watch this BBC video on Happisburgh

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Coasts : Processes of Deposition / Transportation of material

Key Terms :

Prevailing wind direction

Cliff material / debris

Swash

Backwash

Constructive

Destructive waves

Storm wave

Longshore Drift

Example / Case-Study :

Holderness Coast East Yorkshire

Beach at Hornsea & Withernsea

Possible Questions :

How does eroded material get transported along a coastline?

How and why does Longshore Drift take place?

Waves are the main movers of material eroded from cliffs. As waves break they push material up the beach (SWASH); as they fall back to the sea they drag beach material with them (BACKWASH). Gentle waves have a stronger Swash than Backwash so build up the beach – known as Constructive Waves. Storm waves have a more powerful Backwash than Swash, so remove more material from a beach – known as Destructive Waves.

Weblinks http://www.s-cool.co.uk/gcse/geography/coasts/coastal-transportation-and-deposition.html

Watch this BBC video clip on Longshore Drift

If waves approach the beach from an angle as a result of the prevailing wind blowing onshore at an angle, the result is LONGSHORE DRIFT. Waves move material up and across the beach (angled Swash), but gravity pulls the backwash straight back to sea at right-angles to the coastline. Over just a few hours this can move material along the coast.

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Coasts : Processes of Deposition / Transportation of material

Key Terms :

Prevailing wind direction

Cliff material / debris

Swash

Backwash

Constructive

Destructive waves

Storm wave

Longshore Drift

Example / Case-Study :

Holderness Coast East Yorkshire

Beach at Hornsea & Withernsea

Possible Questions :

What is the evidence that Longshore Drift is taking place?

Are there any benefits of Longshore Drift?

What is the evidence that Longshore Drift is

taking place?

Weblinks

http://www.yorkshire-east-coast-unofficial-guide.com/withernsea-sands.html

Benefits of Longshore Drift :

•Builds up wider beaches at coastal resorts with groynes so more people can use the beach

•Provides more beach material further along the coast to help protect coastline from erosion

Waves approach at an angle to the

shore

Beach material is Higher on the side of

the groyne facing the prevailing wind

and waves

Beach is Wider on the side of the

groyne facing the approaching waves

Eroded material (chalk pebbles

from Flamborough

head) are found down the coast

where the natural cliff material is

Boulder Clay

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Coasts : Features of Deposition / Spit, bar and tombolo

Key Terms :

Longshore Drift

Deposition feature

Spit

Bar

Tombolo

Peninsula

Example / Case-Study :

Spurn Head, E. Yorkshire (Spit)

Slapton Ley, Dorset (Bar)

Chesil Beach, Dorset (Tombolo)

Possible Questions :

Describe and explain the formation of a coastal feature of deposition.

What is the difference between a Bar and a Spit?

Weblinks

http://www.chesilbeach.org/Chesil/index.html

Watch this BBC video clip on a Spit

As cliff and beach material is transported along a coast by Longshore Drift, if the flow is interrupted or slowed down, the material is DEPOSITED to form a range of Features of Deposition. A Spit, bar and tombolo are all low-lying beaches made up of sand, gravel, pebbles and rise just a few metres above high tide. Beach grasses may grow in them (marram grass) and the roots then stabilise the features and wind-blown sand may accumulate further. But their low height may mean they are submerged, altered or washed away in severe storms when Erosion is more powerful than Deposition.

Spit A linear beach that extends from the shore across a river estuary or along the coast – but doesn’t join on to any other feature. It is recurved at its end depending on which is the most powerful current.e.g Spurn Head, E. Yorkshire

Bar A Spit which goes right across a bay and joins onto a shore at the other side. Usually where there is no strong river current trying to get to the seae.g Slapton Ley, Dorset

Tombolo A Spit which extends out to join on to an island so that it forms a Peninsula rather than an Island.e.g. Chesil Beach, Dorset

Is this a

SPIT

TOMBOLA or

BAR ?

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Coasts : Features of Deposition / Spit, bar and tombolo

Key Terms :

Longshore Drift

Deposition feature

Spit

Bar

Tombolo

Recurved

Lagoon

Salt Marsh

Example / Case-Study :

Spurn Head, E. Yorkshire (Spit)

Slapton Ley, Dorset (Bar)

Chesil Beach, Dorset (Tombolo)

Possible Questions :

What is the environmental value of a spit, bar or tombolo?

Are these permanent or temporary features of coastal deposition?

Weblinks

http://www.field-studies-council.org/slaptonley/

A SPIT is unable to extend right across an estuary due to the force of the river current finding a route out to the sea.It is RECURVED at the end in the direction of the strongest of the two currents. In Spurn Head’s case, the North Sea current is more powerful than the River Humber current, so the spit curves in towards the estuary.

A TOMBOLO – where a spit extends out to an island and joins it to the mainland.The most famous is CHESIL BEACH in Dorset at 11 miles long.

A BAR is a spit which extends across a bay and reaches the shore on the other side. The water which is cut off becomes a salt-water LAGOON of still water. Eventually, over time the lagoon fills in with wind-blown sand, sediment, reeds and other vegetation and becomes a marsh.This is SLAPTON LEY in Dorset.

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River Humber Current North Sea Curre

nt

A

E

D

C

B

A : Sea erodes the coast and Longshore Drift transports material down the coast

B : The North Sea and R. Humber currents meet, slow down & deposit their material. The N.Sea current is stronger so the recurved spit bends in to the Humber channel.

C : As the Spit head grows southwards, erosion still takes place up-coast

D : The neck of the spit has more erosion than deposition – so gets thinner

E : The sea breaks through the neck, the spit head is an island and is eroded away

Coasts : Features of Deposition / Evolution of Spurn Head, E. Yorkshire – A SPIT 14

Direction of the River Humber current

Directio

n of t

he North

Sea curre

nt

Deposited river silt (

mud)

Turbulence where 2 currents meetRecent Deposition

Thin neck of spit

Likely breach

Spurn Lighthouse

Spurn Lifeboat station

Coasts : Features of Deposition / Features of the spit at Spurn Head 15

Coasts : Features of Deposition / Issues of coastal protection of a Spit

Key Terms :

Longshore Drift

Deposition feature

Spit

Estuary

Example / Case-Study :

Spurn Head, E. Yorkshire (Spit)

Possible Questions :

Why are there disagreements about whether to protect coasts from further erosion?

What are the issues surrounding the management of sensitive coastal environments?

Weblinks

http://www.spurnpoint.com/

http://news.bbc.co.uk/1/hi/england/humber/8439570.stm

The thin neck of Spurn Head is only a few metres wide. Victorian coastal engineers tried to stop the spit eroding away at its thinnest point over a hundred years ago, but their wooden groynes have now collapsed and are no longer effective. The issue is whether to protect the spit from further erosion, or let the sea carry out its operations, and erode it away.

Issues if the spit is allowed to be eroded away:

•The 7 homes of Britain’s only full-time lifeboat crew of the Humber lifeboat are located at the southern end. They would have to be relocated – possible to Grimsby if the spit eroded away – meaning a longer journey time into ships in distress in the N. Sea

•The Humber pilots are based there too – they go out to ships entering the Humber estuary – one of the busiest in Britain – to guide ships around the shifting and dangerous sand-banks of the estuary.

•The spit is an important route for migrating birds from the continent which, in spring, use the spit to guide them into Britain, and in autumn on their flights south for the winter.

•The Spit is managed by the Yorkshire Wildlife Trust and is a vital habitat for many plants & insects

Issues if the spit is protected from further erosion

•The costs of protecting the entire length of the spit would be huge.

•The Victorian attempts to keep the spit in one position have increased its current problems as the Holderness coast to the north continues to erode westwards – leaving the spit more exposed to NE winds and waves.

•The erosion of material from the spit provides important material to help protect the beaches south of the Humber in Lincolnshire and even the Netherlands. Stopping the erosion and movement of this material from Spurn would cause faster erosion elsewhere.

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