Coasts ; processes Flashcards
Name all types of erosion.
attrition
abrasion
hydraulic action
solution
Describe attrition.
loose sediment is swirled by waves.
sediment collides with each other - gradually wearing away, becoming smaller, rounder, smoother.
Describe abrasion.
sediment is picked up by waves.
thrown against cliff, wears cliff away. acts like sandpaper.
describe hydraulic action.
water enter cracks in the rock.
this compresses air inside.
air blasts out, forcing rock apart.
Describe solution.
seawater dissolves material from rock.
happens along limestone/chalk coasts when calcium carbonate is dissolved.
Name all types of transportation.
traction saltation suspension solution longshore drift
Describe traction.
boulders are rolled along the seafloor.
Describe saltation.
beach material is bounced along the seafloor.
Describe suspension.
beach material is suspended (dispersed) and carried by the waves.
Describe solution.
material is dissolved and carried by the water.
Describe longshore drift.
wave approaches coast at an angle due to prevailing wind direction.
gravity acts on backwash and falls back to sea at a right angle.
transports material along coastlines.
Define deposition.
process where sediment is dropped.
Why does deposition happen?
waves become shallow
there is little wind
[wave energy reduced]
