A wave-cut platform, shore platform, coastal bench, or wave-cut cliff is the narrow flat area often found at the base of a

sea cliff Seacliff or Sea Cliff or Sea Cliffe may refer to: ;Places ''Australia'' *Seacliff, South Australia, suburb of Adelaide * Seacliff Park, South Australia, a suburb of Adelaide *Sea Cliff Bridge, in Illawarra, New South Wales ''New Zealand'' *Seacl ...

or along the shoreline of a

lake A lake is an area filled with water, localized in a basin, surrounded by land, and distinct from any river or other outlet that serves to feed or drain the lake. Lakes lie on land and are not part of the ocean, although, like the much large ...

, bay, or sea that was created by erosion. Wave-cut platforms are often most obvious at low tide when they become visible as huge areas of flat rock. Sometimes the landward side of the platform is covered by sand, forming the beach, and then the platform can only be identified at low tides or when storms move the sand. __TOC__

Formation

Wave-cut platforms form when destructive waves hit against the cliff face, causing an undercut between the high and low water marks, mainly as a result of abrasion,

corrosion Corrosion is a natural process that converts a refined metal into a more chemically stable oxide. It is the gradual deterioration of materials (usually a metal) by chemical or electrochemical reaction with their environment. Corrosion engi ...

and

hydraulic action Hydraulic action, most generally, is the ability of moving water (flowing or waves) to dislodge and transport rock particles. This includes a number of specific erosional processes, including abrasion, at facilitated erosion, such as ''static eros ...

, creating a wave-cut notch. This notch then enlarges into a cave. The waves undermine this portion until the roof of the cave cannot hold due to the pressure and freeze-thaw or biological weathering acting on it, and collapses, resulting in the cliff retreating landward. The base of the cave forms the wave-cut platform as

attrition Attrition may refer to *Attrition warfare, the military strategy of wearing down the enemy by continual losses in personnel and material **War of Attrition, fought between Egypt and Israel from 1968 to 1970 **War of attrition (game), a model of agg ...

causes the collapsed material to be broken down into smaller pieces, while some cliff material may be washed into the sea. This may be deposited at the end of the platform, forming an off-shore beach. Because of the continual wave action, a wave-cut platform represents an extremely hostile environment and only certain

organism In biology, an organism () is any living system that functions as an individual entity. All organisms are composed of cells (cell theory). Organisms are classified by taxonomy into groups such as multicellular animals, plants, and ...

s can utilize such a niche.

Use of ancient examples

Ancient wave-cut platforms provide evidence of past sea and lake levels. Raised and abandoned platforms, sometimes found behind modern beaches, are evidence of higher sea levels in the geological past, and have been used to identify areas of isostatic adjustment. By using scientific dating methods, or examination of marine fossils found on the platform, it is possible to work out when the platform was formed, thus giving geographers and geologists information about sea levels at known times in the past. This has been used in the United Kingdom and other previously glaciated areas to calculate the rate at which land is rising now that it is no longer covered in ice. Where the coastline itself is changing due to seismic action, there may be a series of platforms showing earlier sea levels and indicating the amount of uplift caused by various

earthquake An earthquake (also known as a quake, tremor or temblor) is the shaking of the surface of the Earth resulting from a sudden release of energy in the Earth's lithosphere that creates seismic waves. Earthquakes can range in intensity, fr ...

Usage of term 'wave-cut'

According to Trenhaile, Sunamura, and Massalink and Hughes, the term 'wave-cut platform' should no longer be used as it assumes that shore platforms are the result of wave action, which is not always true. Shore platforms, like comparable river and lake platforms, are erosional features that develop when removal of saprock and other debris by waves and currents leaves behind a bedrock surface below the water table.Retallack, G.J. and Roering, J.J. 2012: Wave-cut or water-table platforms of rocky coasts and rivers? GSA Today 22(6), 4-9. File:BleikRaisedBeach&Platform.JPG,

Raised beach A raised beach, coastal terrace,Pinter, N (2010): 'Coastal Terraces, Sealevel, and Active Tectonics' (educational exercise), from 2/04/2011/ref> or perched coastline is a relatively flat, horizontal or gently inclined surface of marine origin,P ...

and shore platform,

Bleik Bleik is a fishing village in Andøy Municipality in Nordland county, Norway. The village is located on the northwestern part of the island of Andøya, about southwest of the village of Andenes is the administrative centre of Andøy Municip ...

, Norway File:WaveCutPlatformsAntelopeIslandUT.jpg, Shore platforms from

Lake Bonneville Lake Bonneville was the largest Late Pleistocene paleolake in the Great Basin of western North America. It was a pluvial lake that formed in response to an increase in precipitation and a decrease in evaporation as a result of cooler temperature ...

(

Pleistocene The Pleistocene ( , often referred to as the ''Ice age'') is the geological epoch that lasted from about 2,580,000 to 11,700 years ago, spanning the Earth's most recent period of repeated glaciations. Before a change was finally confirmed in ...

), Utah, United States File:St bees head fleswick bay wave cut platform.JPG, Shore platform at St Bees Head, UK File:Tedbury Camp unconformity.JPG, Jurassic wave-cut platform at Tedbury Camp, southern England

References

{{DEFAULTSORT:Wave-Cut Platform Coastal geography Coastal and oceanic landforms

Formation

Use of ancient examples

Usage of term 'wave-cut'

See also

References