气候变化领域集成服务门户(CCPortal): Evidence for a water system transition beneath thwaites glacier; West Antarctica

CCPortal

DOI	10.1073/pnas.1302828110
	Evidence for a water system transition beneath thwaites glacier; West Antarctica
	Schroeder D.M.; Blankenship D.D.; Young D.A.
发表日期	2013
ISSN	0027-8424
起始页码	12225
结束页码	12228
卷号	110 期号:30
英文摘要	Thwaites Glacier is one of the largest, most rapidly changing glaciers on Earth, and its landward-sloping bed reaches the interior of the marine West Antarctic Ice Sheet, which impounds enough ice to yield meters of sea-level rise. Marine ice sheets with landward-sloping beds have a potentially unstable configuration in which acceleration can initiate or modulate grounding-line retreat and ice loss. Subglacial water has been observed and theorized to accelerate the flow of overlying ice dependent on whether it is hydrologically distributed or concentrated. However, the subglacial water systems of Thwaites Glacier and their control on ice flow have not been characterized by geophysical analysis. The only practical means of observing these water systems is airborne ice-penetrating radar, but existing radar analysis approaches cannot discriminate between their dynamically critical states. We use the angular distribution of energy in radar bed echoes to characterize both the extent and hydrologic state of subglacial water systems across Thwaites Glacier. We validate this approach with radar imaging, showing that substantial water volumes are ponding in a system of distributed canals upstream of a bedrock ridge that is breached and bordered by a system of concentrated channels. The transition between these systems occurs with increasing surface slope, melt-water flux, and basal shear stress. This indicates a feedback between the subglacial water system and overlying ice dynamics, which raises the possibility that subglacial water could trigger or facilitate a grounding-line retreat in Thwaites Glacier capable of spreading into the interior of the West Antarctic Ice Sheet.
英文关键词	Ice sheet stability; Radio glaciology; Subglacial hydrology
语种	英语
scopus关键词	acceleration; Antarctica; article; controlled study; glacier; phase transition; priority journal; shear stress; telecommunication; water supply
来源期刊	Proceedings of the National Academy of Sciences of the United States of America
文献类型	期刊论文
条目标识符	http://gcip.llas.ac.cn/handle/2XKMVOVA/158930
作者单位	Schroeder, D.M., Institute for Geophysics, Jackson School of Geosciences, University of Texas at Austin, Austin, TX 78758, United States; Blankenship, D.D., Institute for Geophysics, Jackson School of Geosciences, University of Texas at Austin, Austin, TX 78758, United States; Young, D.A., Institute for Geophysics, Jackson School of Geosciences, University of Texas at Austin, Austin, TX 78758, United States
推荐引用方式 GB/T 7714	Schroeder D.M.,Blankenship D.D.,Young D.A.. Evidence for a water system transition beneath thwaites glacier; West Antarctica[J],2013,110(30).
APA	Schroeder D.M.,Blankenship D.D.,&Young D.A..(2013).Evidence for a water system transition beneath thwaites glacier; West Antarctica.Proceedings of the National Academy of Sciences of the United States of America,110(30).
MLA	Schroeder D.M.,et al."Evidence for a water system transition beneath thwaites glacier; West Antarctica".Proceedings of the National Academy of Sciences of the United States of America 110.30(2013).