GeographyCoasts

Coastal Erosion [Date]

Today I will:- Know the key terms- Know how a bay and wave cut platform is formed

GeographyCoasts

Processes of Erosion at the Coastline

1. Hydraulic Action: Waves crash against a cliff and drive water under great pressure into cracks in the rock. This pressure squeezes the air and as the wave falls back the air expands explosively, loosening pieces of rock.

2. Corrasion: Corrasion (or abrasion) occurs when stones and pebbles are picked up by waves and thrown against the cliff, causing erosion.

3. Solution: Salty sea water chemically dissolves rocks. This is most noticeable on chalk and limestone cliffs.

4. Attrition: Rock fragments (stones and pebbles) hit against each other and so are reduced in size.

GeographyCoasts

Backwash: As the wave loses its momentum, energy is transferred back to the sea – this return flow is called

backwash.

Swash:The water which

rushes up the beach is called

swash.

The force of the swash and backwash determines whether the waves are

constructive waves or destructive waves.

GeographyCoasts

If the swash is weaker than the backwash (destructive wave), very little material is carried up the beach. With a strong backwash, material will

be removed and the beach will decrease in size.

GeographyCoasts

Wave-cut platformCliff

GeographyCoasts

GeographyCoasts

GeographyCoasts

BayHeadland

GeographyCoasts

GeographyCoasts

GeographyCoasts

GeographyCoasts