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Wave-cut platforms

Coasts of erosion form as a result of high energy waveslarge fetchhigh exposure and limited deposition. They are also associated with drift alligned coasts that are influenced by longshore drift. This transfer of sediment along the coast limits the development of beaches and leads to greater cliff exposure, hence cliff retreat. Coastlines, that are discordant in geology help create typical headland and bay features that also erode over time to form wave-cut platforms and arches and stacks. Wave cut platforms as illustrated in the diagram and shown in the photograph are remnants of the previous cliff line. They form as a ledge of bedrock left behind as the dliff retreats. The platform slopes at at 4-5 degree angle down to the sea. It forms as waves erode the base of the cliff in the 

Cliffs and wave-cut platforms

inter-tidal zone. Waves scour away at the base through processes of abrasionhydraulic action and solution, untill over time awave-cut notch forms. As the notch enlarges, the cliff face becomes undermined untill at some point it collapases under its own weight. Attrition and transportation then remove the cliff debris leaving behind a small bedrock ledge, which marks the old cliff line. This process is repeated over time as the cliff retreats forming a larger wave-cut platfrom. Eventually a beach may develop on the platform which will provide some protection to the cliff and in turn slows down the rate of retreat. Wave-cut platforms are characterised by their gentle sloping angle, hard bedrock and rock pools, which develop unique coastal ecosytems. This is superbly animated in link below: