| 翻訳と辞書 |
| marine terrace ： ウィキペディア英語版 |
marine terrace
A marine terrace, coastal terrace,〔Pinter, N (2010): 'Coastal Terraces, Sealevel, and Active Tectonics' (educational exercise), from http://www.geology.siu.edu/people/pinter/pdf/CoastalExercise.pdf ()〕 raised beach or perched coastline is a relatively flat, horizontal or gently inclined surface of marine origin,〔Pirazzoli, PA (2005a): 'Marine Terraces', in Schwartz, ML (ed) ''Encyclopedia of Coastal Science.'' Springer, Dordrecht, pp. 632-633〕 mostly an old abrasion platform which has been lifted out of the sphere of wave activity (sometimes called "tread"). Thus it lies above or under the current sea level, depending on its time of formation.〔Strahler AH; Strahler AN (2005): ''Physische Geographie.'' Ulmer, Stuttgart, 686 p.〕〔Leser, H (ed)(2005): ‚''Wörterbuch Allgemeine Geographie.'' Westermann&Deutscher Taschenbuch Verlag, Braunschweig, 1119 p.〕 It is bounded by a steeper ascending slope on the landward side and a steeper descending slope on the seaward side〔 (sometimes called "riser"). Due to its reasonably flat shape it is often used for anthropogenic structures like settlements and infrastructure.〔
== Morphology ==
The platform of a marine terrace usually has a gradient between 1°- 5° depending on the former tidal range with commonly a linear to concave profile. The width is very variable, reaching up to 1000 m, and seems to differ between northern and southern hemisphere.〔Pethick, J (1984): ''An Introduction to Coastal Geomorphology.'' Arnold&Chapman&Hall, New York, 260p.〕 The cliff faces, delimiting the platform, can vary in steepness depending on the relative roles of marine and subaerial processes.〔Masselink, G; Hughes, MG (2003): ''Introduction to Coastal Processes & Geomorphology.'' Arnold&Oxford University Press Inc., London, 354p.〕 At the intersection of the former shore (wave-cut/abrasion-) platform and the rising cliff face it commonly retains a shoreline angle or inner edge (notch) which indicates the location of the shoreline at the time of maximum sea ingression and therefore a paleo sea level.〔Cantalamessa, G; Di Celma, C (2003): 'Origin and chronology of Pleistocene marine terraces of Isla de la Plata and of flat, gently dipping surfaces of the southern coast of Cabo San Lorenzo (Manabí, Ecuador)', ''Journal of South American Earth Sciences'' v. 16, pp. 633–648 〕 Sub-horizontal platforms usually terminate in a low tide cliff and it is believed that the occurrence of these platforms depends on tidal activity.〔 Marine terraces can extend for several tens of kilometers parallel to the coast.〔
Older terraces are covered by marine and/or alluvial or colluvial materials while the uppermost terrace levels usually are less well-preserved.〔Ota, Y; Hull, AG; Berryman, KR (1991): 'Coseismic Uplift of Holocene Marine Terraces in the Pakarae River Area, Eastern North Island, New Zealand', ''Quaternary Research'' v. 35, pp. 331-346 〕 While marine terraces in areas of relatively rapid uplift rates (> 1 mm/year) can often be correlated to individual interglacial periods or stages, those in areas of slower uplift rates may have a polycyclic origin with stages of returning sea levels after times of exposure to weathering.〔
Marine terraces can be covered by a wide variety of soils with complex histories and different ages. In protected areas allochtonous sandy parent materials from tsunami deposits may be found. Common soil types found on marine terraces include planosols and solonetz.〔Finkl, CW (2005): 'Coastal Soils' in Schwartz, ML (ed) ''Encyclopedia of Coastal Science.'' Springer, Dordrecht, pp. 278-302〕
抄文引用元・出典: フリー百科事典『 ウィキペディア（Wikipedia）』
■ウィキペディアで「marine terrace」の詳細全文を読む
スポンサード リンク
| 翻訳と辞書 : 翻訳のためのインターネットリソース |
Copyright(C) kotoba.ne.jp 1997-2016. All Rights Reserved.
|
|