Rates of Erosion

Question 1

Breaking point of a wave.

Answer 1

A wave that breaks as it hits the foot of the cliff
releases most energy and causes maximum erosion.

Wave breaks before it hits cliff, much less energy is transmitted - wave cut platform

Question 2

Wave steepness.

Answer 2

Higher energy waves associated with longer fetch distances, have a high steep appearance.
Most erosive power.

Destructive waves

Question 3

Fetch

Answer 3

How far wave has travelled.

Travelled over long fetch means waves have more energy. Transfer more energy to waves meaning larger/ destructive / high energy waves - less obstacles

Question 4

Sea depth

Answer 4

Steeply shelving seabed at coast will generate higher / steeper waves.

Deeper waves will not generate steep / destructive waves as there isn’t as much friction with sea bed.

Question 5

Coastal configuration

Answer 5

Headland attract waves through refraction - destructive waves / high erosion here.

But sheltered bay receives slow / low energy waves - deposition

Question 6

Beach presence

Answer 6

Beaches absorb wave energy and act aw natural buffer from destructive waves and marine Erosion.

Steep/ narrow beaches easily dissipate energy from flatter waves.

Wider/ spread out beaches best at dissipating high energy waves.

Shingle beaches deal better with destruct waves as energy is rapidly dissipated through friction / percolation.

Question 7

Human activity

Answer 7

People remove natural protection like sand/shingle -erosion.

Reduce erosion by implementing HE/SE structures.

But this ^^ could lead to erosion else where like mappleton:

Question 8

Name the last important factor is determining nature of Erosional processes that take place

Answer 8

Geology

Question 9

Lithology

Answer 9

Characteristics of rocks - resistant to erosion ? Permeable ?

Question 10

Example of resident rock

Answer 10

Granite

Question 11

Less resistant rock

Answer 11

Clay

Question 12

Problem with limestone

Answer 12

Well jointed.

Sea can penetrate / exploit lines of weakness leaking them more vulnerable to erosion.

Question 13

Differential variation

Answer 13

Variation in the rates at which rocks wear away.

Question 14

Concordant

Answer 14

Different Rocks types running parallel to coast.
Protect coastline - allow sea to break through in some places.

Worbarrow Bay

Question 15

Discordant

Answer 15

Alternating bands of Rocks run at right angles to coast allowing sea to penetrate along weaker clays to produce large bays.

Swanage Bay

Question 16

Dip of rocks.

Answer 16

Steepest cliffs = horizontal strata or dip gently inland.

Gentle cliffs = dip towards cost

Question 17

What falls under the geology of the coastline ?

Answer 17

Lithology

Structure

Concordant / discordant

Dip