Coasts

Types of coastal erosion

Types of waves

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  • Created by: Ollie
  • Created on: 23-11-10 19:12

Types of coastal erosion

Hydraulic action - Lots of sea water crashes against the land. Air and water get trapped and compress in the rock surface cracks. When the sea moves away the air expands explosively wekaing the rocks, enlarging the cracks and breaking pieces off

Corrasion - Very effective and is caused by broken rock fragments battering the cliffs (breaking off pieces of rock

Attrition - Occurs when rock fragments grind each other down into smaller and smoother pebbles / sand this is later desposited as beaches

Corrosion - Involves chemical action of sea on rock. If the rock is limestone it dissolve sin the sea water

Wave pounding - The constant battering of waves erodes cliffs

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Longshore Drift

Longshore drift happens:

Waves break at an oblique angle to the shore due to prevailing winds.

This means that each wave pushes material along the beach a bitg more

(http://upload.wikimedia.org/wikipedia/commons/thumb/f/fb/Longshore_drift.svg/800px-Longshore_drift.svg.png)

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Types of Waves

Constructive waves

  • Operate in calm water (metre high)
  • The swash is strong and erosion is limited
  • They're involved with the transport and deposition of materials creating landforms

Destructive Waves

  • Operate in storm condidtions (5 or 6 metres high)
  • The backwash is strong and there is a lot of erosion
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Constructive and Destructive Waves

(http://www.revisionworld.co.uk/files/constructive.jpg)

(http://www.revisionworld.com/files/destructive.jpg)

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