Coastal Processes

Question 1

What is weathering?

Answer 1

The breakdown of rock at or near the surface. This is mainly caused by weather conditions such as changes in temperature

Question 2

What are the 3 types of weathering?

Answer 2

•mechanical
•chemical
•biological

Question 3

What is mechanical weathering?

Answer 3

•Water gets into the cracks and joints in the rock, and as it freezes, the volume expands.
•This puts pressure on the surrounding rock and the crack is widened.
This is called ‘freeze-thaw action’. Over time the size of the crack increases, until a block of rock breaks off.

Question 4

What is biological weathering?

Answer 4

Plant roots grown in cracks in the rocks. Animals such as rabbits burrow into weak rocks.

Question 5

What is chemical weathering?

Answer 5

This occurs when water reacts with the calcium carbonate in rocks like limestone and . The calcium carbonate dissolves and is washed away in solution, weakening the rock.

Question 6

What is mass movement?

Answer 6

When rocks are weakened by weathering and erosion and move down the slope under the influence of gravity. Often erosion from the sea and weathering work together to cause sliding, slumping and rock falls.

Question 7

What are the 3 types of mass movement?

Answer 7

•sliding
•slumping
•rock falls

Question 8

What is sliding?

Answer 8

When large pieces of land slide down the slope quickly without warning

Question 9

What is slumping?

Answer 9

Cliffs made of clay become saturated during heavy rainfall and the land slides down towards the sea

Question 10

What is rock fall?

Answer 10

When pieces of rock are continually weathered and eroded until they separate from the cliff in whole parts and fall offf

Question 11

What are the 4 types of erosion?

Answer 11

•abrasion
•attrition
•hydraulic action
•solution

Question 12

What is abrasion?

Answer 12

When lose rocks, called sediment, are thrown against the cliff by waves. This wears the cliff away and chips bits of rock off the cliff.

Question 13

What is hydraulic action?

Answer 13

Water is forced into cracks in the rock.
This compresses the air. When the wave retreats the compressed air blasts out. This can force the rock apart.

Question 14

What is attrition?

Answer 14

When lose sediment, knocked off the cliff by hydraulic action and abrasion, is swirled around by waves. It constantiy collides with other sediment, and graduall. gets worn down into smaller, and rounder sediment.

Question 15

What is solution?

Answer 15

This happens when seawater dissolves material from the rock. It happens along limestone and chalk coasts, when calcium carbonate is dissolved.

Question 16

What is transportation?

Answer 16

Once material is eroded, the sea transports it, or carries it away.

Question 17

What is suspension?

Answer 17

When fine sediment is carried as a suspension in the water, making it look muddy or murky.

Question 18

What is traction?

Answer 18

When larger pebbles and cobbles are rolled along the sea bed.

Question 19

What is saltation?

Answer 19

When small pebbles are moved when one pebble hits another, causing it to bounce. This bouncing can set up a chain reaction.

Question 20

What is solution in terms of transportation ?

Answer 20

When dissolved material is carried along in solution, so you can’t see it.

Question 21

What is longshore drift?

Answer 21

The zigzag movement of sediment along a shore caused by waves going up the beach at an oblique angle (Swash) and returning at right angles (backwash). This results in the gradual movement of beach materials along the coast.

Question 22

What is wave refraction?

Answer 22

Coastal deposition takes places in areas where the flow of water slows down. Waves lose energy in sheltered bays and where water is protected in by spits or bars. Here sediment can no longer be carried or moved and is therefore deposited. This explains why beaches are found in bays, where the energy of the waves is reduced.