Coastal Processes (Basics, Waves, Erosion, Weathering, Movement)

How does fetch affect waves?

A longer fetch creates more powerful, destructive waves.

What are constructive waves?

Low energy waves with strong swash and weak backwash that deposit sediment.

What are destructive waves?

High energy waves with weak swash and strong backwash that remove sediment.

What are Landslides?

When blocks of rock slide along bedding planes

What is abrasion (corrasion)?

The process of rocks and pebbles crashing against rock and wearing them away

What is attrition?

Rocks collide with each other and break into smaller, smoother pieces.

What is biological weathering?

The breakdown of rock by plants or animals, e.g. roots growing in cracks.

What is chemical weathering?

The breakdown of rock through chemical reactions, especially in limestone.

What is fetch?

The distance of open water that the wind has travelled over.

What is hydraulic action?

The force of the waves hitting a cliff. The waves also compress air into cracks in the cliff, forcing it apart.

What is longshore drift?

Sediment moves along the coast due to angled swash and straight backwash.

What is mass movement?

the downhill movement of rock or soil under gravity

What is mechanical weathering?

The physical breakdown of rock without chemical change, e.g. freeze-thaw.

What is rockfall?

A type of mass movement where fragments of rock break away from the cliff face, often due to freeze-thaw weathering.

What is slumping/rotational slip?

When heavy saturated soil suddenly slips in a rotational movement

What is solution (corrosion)?

Acidic seawater dissolves soluble rocks like limestone and chalk.

What is the coast?

The area where the land meets the sea.

What physical processes shape the coast?

Erosion, weathering, mass movement, transportation and deposition.

Why is sediment deposited on the coast?

Waves lose energy, especially in sheltered areas or where the coastline changes direction.