Erosional landforms: cliffs and wave-cut platforms, caves, arches and stacks.

Question 1

What is a cliff, and how is it formed?

Answer 1

A steep, near-vertical rock face formed at the coast due to erosion.

1. Waves erode the base of the rock through processes like hydraulic action, abrasion, and solution.
2. Undercutting forms a wave-cut notch.
3. The overhanging rock becomes unstable and collapses.
4. This process repeats, causing the cliff to retreat over time.

Question 2

What is a wave-cut platform, and how does it form?

Answer 2

A gently sloping, flat area of rock extending from the base of a cliff into the sea.

1. As the cliff retreats, the material eroded from the cliff is carried away, leaving a flat platform.
2. Continuous wave erosion smoothens the platform.
3. The platform is exposed at low tide.

Question 3

How are caves formed along coastal cliffs?

Answer 3

1. Weaknesses or joints in the rock are exploited by wave processes like hydraulic action and abrasion.
2. These processes enlarge the weakness, forming a cave.
3. Caves often occur in headlands made of less resistant rock.

Question 4

What are arches, and how do they form from caves?

Answer 4

1. If a cave enlarges enough to penetrate through a headland, an arch is formed.
2. Continuous erosion widens and deepens the arch.

Example: Durdle Door in the UK.

Question 5

What are stacks, and how do they form from arches?

Answer 5

1. As erosion continues, the roof of an arch becomes unstable and collapses.
2. This leaves a vertical, isolated column of rock called a stack.

Example: Old Man of Hoy in Scotland.

Question 6

What are stumps, and how do they form from stacks?

Answer 6

1. Stacks are continuously eroded by wave action at their base.
2. Eventually, the stack collapses, leaving a smaller, lower structure called a stump.
3. Stumps may only be visible at low tide.

Question 7

What are the key processes involved in forming erosional landforms?

Answer 7

Hydraulic Action
Abrasion
Solution
Attrition

Question 8

What is Hydraulic Action

Answer 8

Waves compress air in rock cracks, causing pressure and breaking the rock.

Question 9

What is abrasion

Answer 9

Rocks and sediment in waves wear down cliff surfaces.

Question 10

What is solution

Answer 10

Minerals dissolve in water.

Question 11

What is attrition

Answer 11

Rock fragments become smaller and rounder through collision.