Sediment Cells

Question 1

Where do coastal sediments come from?

Answer 1

River channels and estuaries (85%)
Sea bed (5%)
Beaches (5%)
Cliff erosion (5%)

Question 2

What do offshore bars and sandbanks act as?

Answer 2

Sediment stores/sinks

Question 3

How many sediment cells have been identified in England and Wales?

Answer 3

11

Question 4

What type of system are sediment cells?

Answer 4

Closed system. Finer particles transfer between cells

Question 5

What is dynamic equilibrium?

Answer 5

Balanced state of a system when inputs and outputs are equal

Question 6

What happens if one element changes e.g. Decrease in supply of sediment, upsetting the equilibrium?

Answer 6

Process of feedback, the system adjusts to changes, regaining equilibrium

Question 7

Give an example of a coast working toward equilibrium

Answer 7

Destructive and constructive waves

Question 8

Give a brief description of the negative feedback loop

Answer 8

1. Storm waves accelerate erosion
2. Deposition offshore forming sandbank
3. Waves break on sandbank due to friction
4. ‘Normal’ conditions return, waves transport sediment back to coast