Marine erosion

Question 1

How are caves formed?

Answer 1

Formed by hydraulic action and abrasion on either side of the headland, tunneling through to form a natural arch.

Question 2

How are stacks formed?

Answer 2

When natural arches collapse due to gravity and the impact of weathering.

Question 3

What is hydraulic action?

Answer 3

Air trapped in cracks and fissures is compressed by the force of waves crashing against the cliff face.
Pressure forces cracks open, meaning more air is trapped and greater force is experienced in the next cycle of compression.
The process dislodges blocks of rock from the cliff face.

Question 4

What is abrasion?

Answer 4

Sediment picked up by breaking waves is thrown against the cliff face.
The sediment acts on the cliff like a tool, chiseling away at the surface and gradually wearing it down.

Question 5

What is attrition?

Answer 5

As sediment is moved around by waves, the numerous collisions between particles slowly chip fragments off the sediment, making it smaller and more rounded over time

Question 6

What is corrosion (solution)

Answer 6

Carbonate rocks (limestone) are vulnerable to solution by rainwater, spray from the sea and seawater.