Coastal Processes and Landforms

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Coastal Processes and Landforms
Constructive Waves - Swell or surging waves created by distant storms (low frequency (6-8/minute); long wavelength (up to 100m); low flatter waves (<1m); low energy and stronger swash than backwash Destructive Waves - Storm or plunging waves created by local winds / storms (high frequency (10-12/minute); short wavelength (<20m); high steep wave (>1m); high energy and backwash stronger than swash Fetch - the distance over which wind has blown (i.e. distance a wave travels from when it starts formation to when it breaks) Standing wave clapotis - where this is deep water at a coastline with steep hard rock cliffs and so waves don't break, energy is just reflected Swash - the movement of water up a beach

Backwash - the movement of water back down a beach
Wave Crest - Highest point of the wave
Wave Trough - Lowest point of the wave
Wave Height - The distance between the crest and the trough of a wave Wave Length - The distance between two wave crests
Wave Frequency - The number of waves per minute
Wave Period - The time between two successive crests / troughs (secs) Wave Steepness - Ratio of Wave Height:Wave Length
Wave Base - Depth below which there is no orbital movement
Wave Refraction - where waves become increasingly parallel to the coast - occurs as waves approach an irregular coastline Hydraulic Action - An erosion process - where air becomes trapped and compressed in a joint / crack in a rock by a breaking wave, gradually breaking rock apart. Abrasion - An erosion process where cliffs are worn away by rocks and boulders thrown against them by the waves Solution - An erosion process where acids in the sea water gradually dissolve minerals in rocks. Wave Pounding - An erosion process where the shear force of the waves constantly hitting again cliffs gradually breaks them down (waves can have considerable energy - up to 30 tonnes per m2) Attrition - An erosion process where rocks and boulders become smaller as...