sediment sources

Question 1

where does sediment come from

Answer 1

streams or rivers:
- bring fine material
estuaries
cliff erosion
offshore sand banks
shells

Question 2

what is seabed disturbance

Answer 2

storms destabalise material on sea floor and move to coast

Question 3

what is sediment cell

Answer 3

length coastline where movement sediment self contained
balance between erosion and deposition

Question 4

how many sediment cells in england and wales

Answer 4

11
size varies
boundaries separate them
LSD redistributes sediment from source to sik

largest ones have subcells that can interact

Question 5

are sediment cells open or closed syst

Answer 5

theoretically closed
but easy for fine sediment move to adjacent cells round headland

Question 6

sediment cells as a system

Answer 6

input:
-sometimes rivers,subaerial syst
-always LSD and offshore banks
-shells
-man generated

output:
-dune erosion
-wind erosion
-dredging

stores:
- beach
-spit
-bar

tranfer
- lsd

process
-erosional
- depositional

Question 7

what to think when sediment q

Answer 7

exposure
rock type
coast defence
rivers

Question 8

positive sediment budget

Answer 8

more added than removed
surplus
coast builds toward sea (accretion)

Question 9

negative sediment budget

Answer 9

more removed than added
deficit
shoreline retreats

Question 10

example of cell

Answer 10

swanage bay coastline cell

N to S rock types:
chalk
wealden clay
purbeck limestone
portland limestone

Question 11

other sediment cell example

Answer 11

south down sediment cell

selsey bill to beachy head

Question 12

why is south downs cell considered system

Answer 12

self contained - closed - but do get fine from river so could spread

could be open as allows mass and energy transfer across system boundary

Question 13

people affect south downs cell

Answer 13

breakwaters in newhaven so more sediment there
- starved seaford beach

shoreham harbour 32000m3 dredged
unatural