Coatal Landforms Cuased By Erosion

Question 1

What are the two types of coastline?

Answer 1

Coastline can be concordant and discordant

Question 2

Hard rock

Answer 2

Hard rocks like limestone and chalk are more resistance, so it takes longer for them to be eroded and weathered by physical process

Question 3

Soft rock

Answer 3

Soft rocks like clay and sandstone are less resistant, which means they are eroded more quickly

Question 4

Discordant coastline

Answer 4

Some coastlines are made up of alternating bands of hard and soft rock that are at right angle to the coast

Question 5

Concordant coastline

Answer 5

On a concordant coastline there is a alternating band of hard and soft rock which are parallel to the coast

Question 6

Destructive waves

Answer 6

• the waves that carry out erosional process are called destructive waves
• destructive waves are high, steep and have a high frequency (10-14 waves per min)
• they have a high backwash compared to swash this allow material to be removed from the coast

Question 7

Wave-cut platform

Answer 7

Waves cause most erosion at the foot of a cliff this forms a wave-cut notch which is enlarged as erosion continues. The rock above the notch will be unstable and eventually collapses and the collapsed material is washed. This is repeated and as a result in the cliff retreating. The wave-cut platform is the platform thats left behind as the cliff retreats.

Question 8

Where do headlands and bays form?

Answer 8

Headlands and bay form where there are alternating bands of resistant and less resistant rock along a discordant coastline

Question 9

How is a bay formed?

Answer 9

The less resistant rock (e.g clay) is eroded quickly this forms a bay- bays have a gentle slope

Question 10

How is headlands formed?

Answer 10

The less resistant rock (e.g chalk) is eroded more slowly and it’s left jutting out forming a headland- headlands have steep sides.

Question 11

Forms of headland when eroded?

Answer 11

Headlands are eroded to form caves, arches and stacks

Question 12

How are caves formed?

Answer 12

Waves crash into headlands and enlarge the cracks mainly by hydraulic power and abrasion. Repeated erosion and enlargement of cracks cause a cave to form.

Question 13

How are arches formed?

Answer 13

Continued erosion deepens the cave until it breaks through the headland- forming an arch e.g durdle door in dorset

Question 14

How is stacks formed?

Answer 14

Erosion continues to wear away the rock supporting the arch, until it eventually collapses this forms a stack- an isolated rock that’s separate from the headland, e.g Old harry in dorset