Coastal Landscapes

Question 1

What is the difference between weathering and erosion?

Answer 1

Weathering is the breakdown of rocks in situ
Erosion is when rocks are broken down and carried away by something

Question 2

Describe an example of chemical weathering on coasts

Answer 2

In carbonation weathering, carbon dioxide dissolved in rainwater forms weak carbonic acid. This acid reacts with rocks containing calcium carbonate, dissolving them

Question 3

What is abrasion?

Answer 3

When eroded particles in water scrape against rocks, removing small pieces

Question 4

What is attrition?

Answer 4

When eroded particles collide in water, which breaks them up into smaller fragments and make them more rounded

Question 5

Why do destructive waves cause erosion?

Answer 5

Destructive waves are high and steep, so their backwash is stronger than their swash. This means more material is dragged back down the beach than is pushed up onto it

Question 6

Describe how hydraulic power erodes the coastline

Answer 6

When waves crash against rocks, the air in cracks is compressed, putting pressure on the rock
Repeated compression widens the cracks, causing bits of rock to break off

Question 7

What is coastal deposition?

Answer 7

When material carried by seawater is dropped on the coast

Question 8

Describe how long-shore drift causes material to move along the beach.

Answer 8

A wave’s swash carries material up the beach in the direction of the waves
The backwash then carries material back down the beach at right angles to the sea
Over time, the material zigzags along the coast from one end of the beach to the other

Question 9

How does rock type affect the formation of headlands and bays?

Answer 9

Bays and headland form when they’re are alternating bands of resistant and less resistant rock
Bays form when less resistant rock erodes quickly, headlands form when resistant rock erodes slowly

Question 10

Describe how a headland turns into a stack.

Answer 10

Caves form when waves enlarge cracks in headlands
As erosion continues, the cave breaks through the headland, forming an arch
Erosion wears away the rock supporting the arch until it collapses, forming a stack - a rock separated from the headland

Question 11

What is a sea wall? What are the benefits and what are the costs of using them?

Answer 11

A wall made out of a hard material like concrete that reflects waves back to sea
It prevents erosion of the coast and it also acts as a barrier to prevent flooding
Expensive to build and maintain