Coastal Processes

Question 1

What is erosion in terms of coastline?

Answer 1

Wearing away of rock along the coastline

Question 2

What waves are responsible for erosion on the coastline? Why?

Answer 2

Destructive waves

Have a stronger back wash so pulls material away from the shoreline

Question 3

What are four types of erosion?

Answer 3

• hydraulic action
• abrasion
• attrition
• solution

Question 4

Describe hydraulic action

Answer 4

• sheer power of the waves as they smash against the cliff

- air becomes trapped in the cracks in the rock and causes the rock to break apart

Question 5

Describe abrasion

Answer 5

• pebbles grind along a rock platform, like sand paper

- overtime the rock becomes smooth

Question 6

Describe attrition

Answer 6

• when rocks that the sea is carrying knock against each other
• the rocks then break apart to become smaller and more rounded

Question 7

Describe solution

Answer 7

• when sea water dissolved certain types of rocks

- in the uk limestone and chalk cliffs are very prone to this type of erosion

Question 8

Define transportation

Answer 8

The movement of sediment along the coast by waves tides, and currents

Question 9

Describe longshore drift

Answer 9

The movement of material along a coastline due to the angled approach of waves

• material (sediment) is carried by the waves along the coastline
• waves 🌊 approach coast at an angle due to direction of prevailing waves
• swash carries material towards to beach at an angle
• back wash flows back to the sea- down the slope of the beach
• process repeats along the coast in a zig zag movement

Question 10

What are four types of transportation?

Answer 10

• solution
• suspension
• saltation
• traction

Question 11

Describe solution (transportation)

Answer 11

• minerals in rocks like chalk and limestone are dissolved in sea water
• then carried in solution (not visible)

Question 12

Describe suspension

Answer 12

• small particles such as silts and clays are suspended in the flow of water

Question 13

Describe saltation

Answer 13

• small pieces of shingle or large sand grains are bounced along the seabed

Question 14

Describe traction

Answer 14

• large pebbles and larger material are rolled along the seabed

Question 15

Define deposition

Answer 15

Where sediment is dropped due to a reduction in energy of the water

Question 16

Which waves do coastlines have that cause deposition to occur?
What are some factors leading to deposition?

Answer 16

Constructive waves (deposition occurs when the swash is stronger than the backwash
Factors:
- waves start to slow down and loose energy
- shallow water
- sheltered areas e.g. bays
- little or no wind