3.2 - Sediment Cells

Question 1

What is a sediment cell?

Answer 1

• Stretch of coastline where movement of sediment is supposedly self contained
• closed system of inputs, transport, outputs

Question 2

What are the deposition processes?

Answer 2

Gravity settling - settling due to low energy
Flocculation - small clay particles clump together

Question 3

How is sediment transported?

Answer 3

• LSD
• Currents (marine transport processes)
• wind (aeolian processes)

Question 4

Examples of inputs into a sediment cell?

Answer 4

• eroded material from headlands and cliffs
• eroded material carried by rivers deposited at coast (estuary/delta)

Question 5

What does it mean if a sediment cell is open?

Answer 5

Sediment is removed or added by:
- wind
- tides
- tidal currents

Question 6

What does it mean if a system is semi-closed?

Answer 6

Only small material can make it out of cells

Question 7

How can a sediment cell be closed?

Answer 7

• natural barriers stop sediment being moved out of cells

Eg. Start Point (headland), Thames Estuary

Question 8

What is an example of a sediment cell?

Answer 8

Christchurch Bay

Question 9

What are the transport processes active at Christchurch Bay?

Answer 9

• Longshore drift
  
  • W to E

Question 10

What are the sources at Christchurch Bay?

Answer 10

• Cliff erosion at Highcliffe
• Deposition of sediment load of West Solent

Question 11

What are the sinks at Christchurch Bay?

Answer 11

• Hurst Spit
• Dolphin Bank (Offshore Bar)

Question 12

How is Christchurch Bay a closed cell?

Answer 12

• West Solent disrupts longshore drift

Question 13

How is Christchurch Bay an open cell?

Answer 13

Double spit at Christchurch Harbour allows sediment to skip over from adjacent cell