Win 2016: Coastal Erosion

Question 1

What sort of sea defenses can be used?

Answer 1

Groynes

Sea wall

Rip rap

Rock armour

Beach nourishment - Adding more sand and shingle

Question 2

Explain the formation of one land form at a chalk headland.

Answer 2

In a chalk head land a cave, arch, stack or stump could form. I will describe the formation of the stack.

A crack in the rock is enlarged by hydraulic action and abrasion. Over time the crack will widen to form a cave, this will then erode through the headland to form an arch.

At the same time as the base and side of the headland are being eroded weathering will attack the top of the headland.

This will lead to the roof of the arch eventually collapsing due to gravity. This will leave a stack.

These processes show how a stack is formed.

Question 3

Crack, cave arch stack stump: How is the crack formed?

Answer 3

Hydraulic action and abrasion attack a fault in the rock.

Question 4

Crack, cave arch stack stump: How is the cave formed?

Answer 4

The crack is enlarged to form a cave. A blowhole may be formed by upwards erosion.

Question 5

Crack, cave arch stack stump: How is the arch formed?

Answer 5

Hydraulic action and abrasion widen the cave and eventually cut through to the other side of the headland to form an arch.

Question 6

Crack, cave arch stack stump: How is the stump formed?

Answer 6

Roof of the arch eventually collapses leaving a stack due to weathering. Hydraulic action, abrasion and weathering from the top reduce the height of the stack to a stump.

Question 7

Crack, cave arch stack stump: How is the stump formed?

Answer 7

Weathering and erosion turn the stack into a stump.

Question 8

Here’s a diagram of the formation of a crack, cave, arch, stack, stump on a headland.

Answer 8