气候变化领域集成服务门户(CCPortal): Changes in flow of Crosson and Dotson ice shelves, West Antarctica, in response to elevated melt

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DOI	10.5194/tc-12-1415-2018
	Changes in flow of Crosson and Dotson ice shelves, West Antarctica, in response to elevated melt
	Lilien D.A.; Joughin I.; Smith B.; Shean D.E.
发表日期	2018
ISSN	19940416
卷号	12 期号:4
英文摘要	Crosson and Dotson ice shelves are two of the most rapidly changing outlets in West Antarctica, displaying both significant thinning and grounding-line retreat in recent decades. We used remotely sensed measurements of velocity and ice geometry to investigate the processes controlling their changes in speed and grounding-line position over the past 20 years. We combined these observations with inverse modeling of the viscosity of the ice shelves to understand how weakening of the shelves affected this speedup. These ice shelves have lost mass continuously since the 1990s, and we find that this loss results from increasing melt beneath both shelves and the increasing speed of Crosson. High melt rates persisted over the period covered by our observations (1996-2014), with the highest rates beneath areas that ungrounded during this time. Grounding-line flux exceeded basin-wide accumulation by about a factor of 2 throughout the study period, consistent with earlier studies, resulting in significant loss of grounded as well as floating ice. The near doubling of Crosson's speed in some areas during this time is likely the result of weakening of its margins and retreat of its grounding line. This speedup contrasts with Dotson, which has maintained its speed despite increasingly high melt rates near its grounding line, likely a result of the sustained competency of the shelf. Our results indicate that changes to melt rates began before 1996 and suggest that observed increases in melt in the 2000s compounded an ongoing retreat of this system. Advection of a channel along Dotson, as well as the grounding-line position of Kohler Glacier, suggests that Dotson experienced a change in flow around the 1970s, which may be the initial cause of its continuing retreat. © Author(s) 2018.
学科领域	advection; floating ice; grounding line; ice mechanics; ice retreat; ice shelf; remote sensing; snowmelt; Antarctica; Kohler Glacier; West Antarctica
语种	英语
scopus关键词	advection; floating ice; grounding line; ice mechanics; ice retreat; ice shelf; remote sensing; snowmelt; Antarctica; Kohler Glacier; West Antarctica
来源期刊	Cryosphere
文献类型	期刊论文
条目标识符	http://gcip.llas.ac.cn/handle/2XKMVOVA/119173
作者单位	Polar Science Center, Applied Physics Lab, University of Washington, Seattle, WA, United States; Department of Earth and Space Sciences, University of Washington, Seattle, WA, United States; Department of Civil and Environmental Engineering, University of Washington, Seattle, WA, United States
推荐引用方式 GB/T 7714	Lilien D.A.,Joughin I.,Smith B.,et al. Changes in flow of Crosson and Dotson ice shelves, West Antarctica, in response to elevated melt[J],2018,12(4).
APA	Lilien D.A.,Joughin I.,Smith B.,&Shean D.E..(2018).Changes in flow of Crosson and Dotson ice shelves, West Antarctica, in response to elevated melt.Cryosphere,12(4).
MLA	Lilien D.A.,et al."Changes in flow of Crosson and Dotson ice shelves, West Antarctica, in response to elevated melt".Cryosphere 12.4(2018).