| 翻訳と辞書 |
| Pressure ridge (ice) ： ウィキペディア英語版 |
Pressure ridge (ice)
A pressure ridge develops in an ice cover as a result of a stress regime established within the plane of the ice. Within sea ice expanses, pressure ridges originate from the interaction between floes,〔A ''floe'' designates any individual pieces of sea ice larger than .〕 as they collide with each other.〔http://nsidc.org/cryosphere/seaice/index.html.〕〔http://www.ec.gc.ca/glaces-ice/default.asp?lang=En&n=501D72C1-1〕〔http://www.aari.nw.ru/gdsidb/XML/volume1.php?lang1=0&lang2=1&arrange=1.〕〔Weeks, W. F. (2010) ''On sea ice''. University of Alaska Press, Fairbanks, 664 p.〕 Currents and winds are the main driving forces, but the latter are particularly effective when they have a predominant direction.〔 Pressure ridges are made up of angular ice blocks of various sizes that pile up on the floes. The part of the ridge that is above the water surface is known as the ''sail''; that below it as the ''keel''.〔These terms also apply for any floating ice feature, such as icebergs.〕 Pressure ridges are the thickest sea ice features and account for about one-half of the total sea ice volume.〔 Stamukhi are pressure ridges that are grounded and that result from the interaction between fast ice and the drifting pack ice.〔Barnes, P.W., D., McDowell & Reimnitz, E. (1978). Ice gouging characteristics: Their changing patterns from 1975-1977, Beaufort Sea, Alaska. United States Department of the Interior, Geological Survey Open File Report 78-730, Menlo Park, U.S.A., 42 p.〕〔Ogorodov, S.A. & Arkhipov, V.V. (2010) Caspian Sea bottom scouring by hummocky ice floes. Doklady Earth Sciences, 432, 1, pp. 703-707.〕
== Internal structure ==
The blocks making up pressure ridges are mostly from the thinner ice floe involved in the interaction, but it can also include pieces from the other floe if it is not too thick.〔 In the summer, the ridge can undergo a significant amount of weathering, which turns it into a smooth hill. During this process, the ice loses its salinity (as a result of brine drainage). This is known as an ''aged ridge''.〔〔 A ''consolidated ridge'' is one whose base has undergone complete freezing.〔〔 The term ''consolidated layer'' is used to designate freezing up of the rubble just below the water line.〔 The existence of a ''consolidated layer'' depends on air temperature — in this layer, the water between individual blocks is frozen, with a resulting reduction in porosity and an increase in mechanical strength. A keel's depth of an ice ridge is much higher than its sail's height - typically about four times. The keel is also 2-3 times wider than the sail.〔
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「Pressure ridge (ice)」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.
|
|