Topic 4-UK Physical Geography. Coastal weathering and erosion

Question 1

What is the line that is roughly the split between soft and hard rock called? And to which side is the hard rock found

Answer 1

Tees Exe line. North and west of the line

Question 2

What is weathering?

Answer 2

The breakdown of rocks where they are

Question 3

What is erosion?

Answer 3

When rocks are broken down and carried away by something such as seawater

Question 4

Mechanical weathering?

Answer 4

The breakdown of rock without affecting its chemical structure

Question 5

Chemical weathering?

Answer 5

The breakdown of rock by affecting its chemical structure

Question 6

Name the 3 types of weathering

Answer 6

Mechanical, chemical, biological

Question 7

Explain saltwater weathering (mechanical)

Answer 7

• seawater gets into cracks in the rock
• water evaporates and salt crystals form
• these expand and put pressure on the rock
• this repeated causes rock to weather away

Question 8

Explain carbonation (chemical)

Answer 8

• happens in warm, wet conditions
• sea and rainwater have carbon in them which makes them weak carbonic acids
• reacts with rocks that contain calcium carbonate such as carboniferous limestone

Question 9

Explain biological weathering

Answer 9

Breakdown of rocks by living things such as plant roots making their way into cracks. The roots then expand putting pressure on the rock until it breaks off.

Question 10

What is mass movement and how does it work

Answer 10

Mass movement is the movement of a large deposit of material down a cliff at once.

• it happens when the force of gravity is greater than the force holding the materials up
• it causes rapid retreat of the coastline
• happens in wet conditions when the materials are saturated which acts as a lubricant

Question 11

Name the 3 types of mass movement

Answer 11

Slide, slumps and rockfall

Question 12

What are the 3 types of coastal erosion caused by waves

Answer 12

Abrasion, attrition and hydraulic action

Question 13

Attrition is…

Answer 13

When eroded particles in water crash into each other as the waves move them about making them gradually smaller and smoother

Question 14

Hydraulic action is…

Answer 14

When waves crash into rocks forcing air and water into cracks. Repeated compression causes the crack to widen and the rock eventually breaks off

Question 15

Abrasion is when…

Answer 15

Eroded particles in water scrape, rub and crash into the cliff gradually breaking bits off