DOI: 10.5194/tc-12-1415-2018
Scopus记录号: 2-s2.0-85045673790
论文题名: Changes in flow of Crosson and Dotson ice shelves, West Antarctica, in response to elevated melt
作者: Lilien D ; A ; , Joughin I ; , Smith B ; , Shean D ; E
刊名: Cryosphere
ISSN: 19940416
出版年: 2018
卷: 12, 期: 4 起始页码: 1415
结束页码: 1431
语种: 英语
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. Citation statistics:
资源类型: 期刊论文
标识符: http://119.78.100.158/handle/2HF3EXSE/75372
Appears in Collections: 影响、适应和脆弱性 气候变化与战略
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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
Recommended Citation:
Lilien D,A,, Joughin I,et al. Changes in flow of Crosson and Dotson ice shelves, West Antarctica, in response to elevated melt[J]. Cryosphere,2018-01-01,12(4)