| DOI: | 10.1002/2015GL063638
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| 论文题名: | Shear heating and weakening of the margins of West Antarctic ice streams |
| 作者: | Perol T.; Rice J.R.
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| 刊名: | Geophysical Research Letters
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| ISSN: | 0094-9448
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| EISSN: | 1944-9179
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| 出版年: | 2015
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| 卷: | 42, 期:9 | | 起始页码: | 3406
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| 结束页码: | 3413
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| 语种: | 英语
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| 英文关键词: | ice streams
; shear margins
; temperate ice
; triple-valued law
; West Antarctica
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| Scopus关键词: | Glacial geology
; Ice control
; Shear strain
; Shear stress
; Strain rate
; Antarctic ice stream
; Basal resistance
; Drainage systems
; Ice streams
; Limited observations
; Pore fluid pressure
; Triple-valued law
; West antarctica
; Ice
; basal ice
; deformation
; ice movement
; ice stream
; ice thickness
; pore pressure
; shear strain
; Southern Ocean
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| 英文摘要: | Ice streams are fast flowing bands of ice separated from stagnant ridges by shear margins. The mechanisms controlling the location of the margins remain unclear. We use published ice deformation data and a simple one-dimensional thermal model to show that West Antarctic ice stream margins have temperate ice over a substantial fraction of their thickness, a condition that may control their width. The model predicts a triple-valued relation between the thickness-averaged lateral shear stress and the lateral shear strain rate. Observed strain rates at the margins imply that they support slightly less lateral shear stress than adjacent ice within the stream. This requires enhanced basal resistance near the margin. We suggest, in agreement with the limited observations, the presence of a channelized drainage system at the margin that reduces the pore fluid pressure at the ice-till interface, thus increasing the shear stress acting on the yielding Coulomb plastic bed. Key Points Thermal analysis shows nearly all active ice stream margins are temperate The relation between lateral shear stress and strain rate is triple-valued Thermal shear weakening at the margins implies a local basal strengthening ©2015. American Geophysical Union. All Rights Reserved. |
| URL: | https://www.scopus.com/inward/record.uri?eid=2-s2.0-84930473504&doi=10.1002%2f2015GL063638&partnerID=40&md5=68ee88977354986b7431bef801fa01c5
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| Citation statistics: |
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| 资源类型: | 期刊论文
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| 标识符: | http://119.78.100.158/handle/2HF3EXSE/9063
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| Appears in Collections: | 科学计划与规划
气候变化与战略
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作者单位: | School of Engineering and Applied Sciences, Harvard University, Cambridge, MA, United States
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| Recommended Citation: | |
Perol T.,Rice J.R.. Shear heating and weakening of the margins of West Antarctic ice streams[J]. Geophysical Research Letters,2015-01-01,42(9).
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