Investigating Coasts

Investigating Coasts

W.A.L.A : Waves

L.O :Give examples of features created by erosion.

Explain how a cave forms and how it can become an arch and later a stack

Explain the effects of waves on the coast

Video presentation to help you understand in depth:

https://youtu.be/9w8ttSMSVFg

Group Discussion and presentation

• Group 1:Explain the effects of waves on the coast

• Group 2:Explain how a cave forms and how it can become an arch and later a stack

Waves at work

• Waves carry with them some of the energy and power of the wind

• Waves can wear away or erode cliffs due to the strength since they are able to hurl pebbles against the cliffs and sea walls

Waves and Cliffs

• Sea cliffs along rocky coasts have different shapes that were carved by the waves.

• As the waves hurl pebbles and lumps of rock at the base of cliffs they slowly erode them away

• Breaking waves also compress the air trapped in cracks and crevices in rocks of the cliff.

• As the waves pulls back the compressed air explodes out ,weakening the rock so that eventually lumps breaks off it.

• Sea water also weakens and erodes some of the rocks such as chalk and limestone by slowly dissolving them

Cliff erosion

• If a cliff is made up of soft rocks ,such as clay or chalk, it may be eroded quite quickly .

• Harder rocks, such as granite ,are eroded more slowly.

How a cliff is worn away to form a wave-cut platform