Theory question 303
Coastal Landforms(a) List three landforms associated with coastal erosion. (b) Explain the following processes of wave erosion: (i) hydraulic action; (ii) corrasion.
Show the model answer
Model answer
(a) Cliff; wave-cut platform; cave; arch; stack; stump; headland and bay; geo; blowhole.
(b)(i) Hydraulic action: waves hit the coast with great force; water and air are forced into cracks and joints; the air is compressed, then expands suddenly as the wave retreats; repeated pressure widens the cracks and breaks off pieces of rock.
(ii) Corrasion (abrasion): waves pick up sand, pebbles and boulders and hurl them against the cliff base; they act as tools that scrape and undercut the rock, forming notches and wave-cut platforms.
Explanation
Name the tools of corrasion.