erosion/coastal deposition/ longshore drift Flashcards
State all 4 processes of Erosion:
Hydraulic action, Solution, Abrasion and Attrition
What is hydraulic action?
Where the force of waves hits against a cliff face and causes rock to break off.
What is attrition?
Where different bits of material carried by waves and seawater hit against each other
What is abrasion?
Where pieces of material are picked up by the waves and hit or scrape against the seabed or the side of the cliff.
What is solution??
Where weak acids in seawater dissolve soluble rocks like chalk and limestone.
What is deposition?
The dropping of material in seawater onto the coast
Which type of wave deposits material on the coast?
Constructive waves
What increases the amount of coastal deposition taking place?
- Lots of erosion nearby
- More sediment in the ocean
Define backwash:
Carries material down the beach at right angles to the coastline
What is swash?
Carries material up the beach in the same direction as the waves
What is the job of longshore drift?
To transport material along coast lines
What determines the angle of which the swash moves up the beach?
Prevailing wind direction
Describe the process of Longshore Drift:
- A prevailing wind direction angles wind towards the coast.
- The wind controls the waves, therefore the swash will go up the beach at this angle.
- Backwash falls back to the sea at right angles to the coastline because only gravity acts on it.
- This continually moves sediment in a right angled triangle.
Name the 4 Transportational processes:
Traction, Saltation, Suspension, Solution
What is saltation?
Where small sand and gravel particles bounce along the river bed.
