Wave-cut platform: Difference between revisions

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{{Short description|Narrow flat area created by erosion}}

[[Image:Wave cut platform.png|right|frame|The formation of a wave cut platform]]

[[ImageFile:Wavecut_platform_southerndown_panoWavecut platform southerndown pano.jpg|300px|thumb|center|500px|Wave -cut platform at [[Southerndown]], South [[Wales]], UK]]

WavecutA '''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]] or along the shoreline of a [[lake]], [[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==

[[ImageFile:Wave cut platform.png|right|framethumb|The formation of a wave -cut platform|453x453px]]

A '''waveWave-cut platform'''platforms orform '''marine terrace''' is the narrow flat area often seen at the base of a [[sea cliff]] caused by the action of the [[wave]]s. It forms afterwhen destructive waves hit against the cliff face, causing undercuttingan undercut between the high and low water marks, mainly as a result of abrasion, [[corrasioncorrosion]] and [[hydraulic poweraction]], 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 (weathering)|attrition]] 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 terracebeach.<ref>{{Cite web Where|title=Erosional thelandforms coastline- itselfCoastal islandforms changing- dueAQA to- seismicGCSE action,Geography thereRevision may- beAQA a|url=https://www.bbc.co.uk/bitesize/guides/zyfd2p3/revision/1 series|access-date=2025-02-08 of|website=BBC Bitesize |language=en-GB}}</ref><ref>{{Cite web |title=Cliffs and wave-cut platforms showing|url=https://www.internetgeography.net/topics/cliffs-wave-cut-platforms/ earlier|access-date=2025-02-08 sea|website=Internet levelsGeography and|language=en-GB}}</ref><ref>{{Cite indicatingweb the|title=Explain amounthow ofa upliftwave-cut causedplatform byis variousformed [[earthquake]]s- 6 marks {{!}} MyTutor |url=https://www.mytutor.co.uk/answers/34304/GCSE/Geography/Explain-how-a-wave-cut-platform-is-formed-6-marks/ |access-date=2025-02-08 |website=www.mytutor.co.uk}}</ref>

Because of the continual wave action, a wave-cut platform represents an extremely hostile environment and only the toughest ofcertain [[organism]]s can utilize such a [[Ecological niche|niche]].

==Use of ancient examples==

[[Image:Wavecut_platform_southerndown_pano.jpg||thumb|center|500px|Wave cut platform at [[Southerndown]], South [[Wales]]]]

Ancient wavecutwave-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,<ref>Wilson, M.A., Curran, H.A. and White, B. 1998: Paleontological evidence of a brief global sea-level event during the last interglacial. ''Lethaia'' 31: 241-250.{{cite web |url=http://www3.wooster.edu/geology/WilsonEtAl98.pdf |title=Archived copy |access-date=2009-10-28 |url-status=dead |archive-url=https://web.archive.org/web/20110112110235/http://www3.wooster.edu/geology/WilsonEtAl98.pdf |archive-date=2011-01-12 }}</ref> 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.tim likes men

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]]s.

Wavecut 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.

==Usage of term 'wave-cut'==

Ancient wavecut platforms provide evidence of past sea 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.tim likes men

According to Trenhaile,<ref>Trenhaile, A. S. 1987: The Geomorphology of Rock Coasts. (Oxford University Press, Oxford, U.K.) 393 pp.</ref> Sunamura,<ref>Sunamura, T., 1992. Geomorphology of rocky coasts. New York: John Wiley.</ref> and Massalink and Hughes,<ref>Masselink, G and Hughes, M. 2003. Introduction to Coastal Processes and Geomorphology. Hodder Arnold</ref> 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.<ref>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.</ref>

<gallery>

== See also ==

File:BleikRaisedBeach&Platform.JPG|[[Raised beach]] and shore platform, [[Bleik]], Norway

*[[Landform]]

File:WaveCutPlatformsAntelopeIslandUT.jpg|Shore platforms from [[Lake Bonneville]] ([[Pleistocene]]), 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

File:Austinmer, NSW - Brickyard Point, from the north, near boat ramp.jpg|Commonly called a 'rock platform' in Australia, these two examples at [[Austinmer, New South Wales|Austinmer]], N.S.W, are typical of many on the coast of south-eastern Australia.

File:Sydney (AU), Long Reef Headland -- 2019 -- 2786.jpg|The rock platform at [[Long Reef (New South Wales)|Long Reef]], N.S.W., Australia.

File:Wave cut notch and submerged wave-cut platform, Elet Island, Busuanga, Palawan, Philippines.jpg|Wave-cut notch and submerged platform in Elet Island, Busuanga, Palawan, Philippines

</gallery>

== See also ==

*[[Beach]]

*[[Bench (geology)]]

*[[Machair (geography)|Machair]]

*[[Marine terrace]]

*[[Paleoshoreline]]

*[[Raised beach]]

*[[LittleRaised Taiwanshorelines]]

*[[Strandflat]]

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*[[Terrace (geology)]]

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==References==

{{reflist|32em}}

{{coastal geography}}

{{DEFAULTSORT:Wave-Cut Platform}}

[[Category:Landforms]]

[[Category:GeomorphologyCoastal geography]]

[[Category:Coastal and oceanic landforms]]

[[zh:海蝕平臺]]