factors affecting coastal erosion

Question 1

What is lithology?

Answer 1

The physical properties of a rock, eg resistant to erosion, which affect how quickly its eroded.

Question 2

What is the erosion rate of granite?

Answer 2

1mm per year

Question 3

what is the erosion rate of limestone?

Answer 3

1cm per year

Question 4

What is the erosion rate of chalk?

Answer 4

1mm per year

Question 5

What is the erosion rate of boulder clay?

Answer 5

10m per year

Question 6

What is the bedding structure of a rock?

Answer 6

The layers of different rock types within a rock which are subjected to tectonic forces that tilt them so they dip at an angle.

Question 7

What cliffs are formed from horizontal bedding planes?

Answer 7

Steep cliffs where differential erosion takes place. These cliff are usually stable and strong

Question 8

What cliffs are formed from bedding planes that dip seaward?

Answer 8

gentler cliffs which are less stable as loose material can slide down the bedding planes in mass movements.

Question 9

what cliffs are formed from bedding planes that dip landward?

Answer 9

Stable and steeper cliffs as it is difficult to undercut the rock. These contain joints, fissures and cracks between the layers of rock, perpendicular to the beds.

Question 10

what areas of the coast are more resistant to differential erosion?

Answer 10

Areas of high relief, e.g cliffs and headlands.

Question 11

What areas of the coast are less resistant to differential erosion?

Answer 11

Lowland areas, e.g bays and beaches

Question 12

What is the difference between a concordant and discordant coastline?

Answer 12

Concordant coastline: the same geogology and lithology along its lentghwhich is parallel to the coastline.
Discordant coastline: alternate bands of hard and soft rocks along its length which are perpendicular the coastline

Question 13

What is a strata?

Answer 13

A layer of rock

Question 14

How can waves affect the rate and type of erosion?

Answer 14

Most erosion occurs during the winter months when waves are destructive and more powerful due to frequents storms.

Question 15

How can beaches affect the rate and type of erosion?

Answer 15

• If there is a beach in front of a cliff, this will absorb wave energy, limiting erosion

Question 16

How can subaerial processes and mass movement affect erosion?

Answer 16

Weathering and mass movement processes, e.g landslides and freeze thaw, weaken cliffs. Rock fragments produced from these processes may result in increased corrosion/abrasion.

Question 17

How do rock faults affect erosion?

Answer 17

Fissures, cracks and joints are all types of weaknesses and they also increase the rock surface area, this promotes erosion. This can cause headlands and bays to form.

Question 18

How does the rock type affect the rate of erosion?

Answer 18

• Sedimentary rocks, e.g. sandstone, are made from cemented sediment particles so are more vulnerable
• Metamorphic and igneous rocks are made up of interlocking crystals, making them more resistant to erosion.