Geography-coastal landscapes

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What are the main features of a destructive wave?
Strong wave,high frequency,high crest
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What are the main features of a constructive wave?
Low frequency,low crest,runs gently up slop of beach
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How are cliffs and wave-cut platforms formed by erosion?
Weather weakens the top of the cliff. The sea attacks the base of the cliff forming a wave-cut notch. The notch increases in size causing the cliff to collapse. The backwash carries the rubble towards the sea forming a wave-cut platform.Then repeats
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How are headlands formed by erosion?
Headlands are formed when the sea attacks a section of coast with alternating bands of hard and soft rock. Soft rock erodes quicker leaving asection of land jutting out into the sea called a headland.
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How are bays formed by erosion?
The areas where the soft rock has eroded away, next to the headland, are called bays.
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How are caves formed by erosion?
Caves occur when waves force their way into cracks in the cliff face. The water contains sand and other materials that grind away at the rock until the cracks become a cave. Hydraulic action is the predominant process.
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How are arches formed by erosion?
if the cave is formed in a headland, it may eventually break through to the other side forming an arch.
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How are stacks formed by erosion?
The arch will gradually become bigger until it can no longer support the top of the arch. When the arch collapses, it leaves the headland on one side and a stack (a tall column of rock) on the other.
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How are stumps formed by erosion?
The stack will be attacked at the base in the same way that a wave-cut notch is formed. This weakens the structure and it will eventually collapse to form a stump.
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What is corrosion?
a chemical reaction between certain rock types and the salt and other acids in seawater
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What is corasion?
sand and pebbles carried in waves are thrown against the cliff face
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What is hydraulic action?
Pressure exerted by the water which compresses air in cracks. the pressure causes small pieces of rock to break off
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What is attrition?
Waves smash rocks and pebbles on the shore into each other, and they break and become smoother.
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How does longshore drift work?
Continual swash and backwash transports material sideways along the coast. This movement of material is called longshore drift and occurs in a zigzag.
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How are beaches formed by deposition?
Beaches are made up of eroded material that has been transported from elsewhere and deposited by the sea. This is done by constructive waves
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How are spits formed by deposition?
A spit is an extended stretch of beach material that projects out to sea and is joined to the mainland at one end. Spits are formed where the prevailing wind blows at an angle to the coastline, resulting in longshore drift.
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How are bars formed by deposition?
ars are created where a spit grows across a bay, joining two headlands.
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What factors affect cliff recession?
Fetch,geology and coastal management
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What are the effects of cliff recession on the people who live near the coast?
They loose their houses, have to leave and are left in lots of debt. It effects them economically and socially.
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How do people try and predict and prevent coastal flooding?
education,forecasting,planning,building design
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soft engineering techniques
beach replenishment,managed retreat,cliff regrading
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hard engineering techniques
groynes,sea walls,offshore reefs,rip-rap,revetments
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Advantages and disadvantages of beach replenishment
This replaces beach or cliff material that has been removed by erosion or longshore drift ADV:natural defence against DISADV: very expensive
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Advantages and disadvantages of managed retreat
reas of the coast are allowed to erode and flood naturally. Usually this will be areas considered to be of low value. ADV:cheap option DISADV:loss of land
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Advantages and disadvantages of cliff regrading
restructuring the face of a cliff to make the gradient less steep. ADV:
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Advantages and disadvantages of Groynes
A wooden barrier built at right angles to the beach. ADV:Prevents the movement of beach material along the coast by longshore drift. DISADVCan be seen as unattractive.
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Advantages and disadvantages of Sea Walls
A wall built on the edge of the coastline. ADVCan prevent coastal flooding in some areas DISADV:expensive to build
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Advantages and disadvantages of rip-rap?
ADVLarge boulders absorb wave energy and reduce the power of the waves DIS:can look unattractive
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Advantages and disadvantages of revetments?
ADV:strong and provide good protection DISADV:quite expensive
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How is the coast managed at Walton-on-the-Naze?
1.breakwater built 1977 stop longshore drift. 2.1998,300 tonnes of leicester granite placed around tower breakwater.3.1999-beach replenished. 1977-groyne built stop lsd. seawall built 1977,protect soft london clay
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Card 2

Front

What are the main features of a constructive wave?

Back

Low frequency,low crest,runs gently up slop of beach

Card 3

Front

How are cliffs and wave-cut platforms formed by erosion?

Back

Preview of the front of card 3

Card 4

Front

How are headlands formed by erosion?

Back

Preview of the front of card 4

Card 5

Front

How are bays formed by erosion?

Back

Preview of the front of card 5
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