气候变化领域集成服务门户(CCPortal): Velocity response of Petermann Glacier, northwest Greenland, to past and future calving events

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DOI	10.5194/tc-12-3907-2018
	Velocity response of Petermann Glacier, northwest Greenland, to past and future calving events
	Hill E.A.; Hilmar Gudmundsson G.; Rachel Carr J.; Stokes C.R.
发表日期	2018
ISSN	19940416
卷号	12 期号:12
英文摘要	Dynamic ice discharge from outlet glaciers across the Greenland Ice Sheet has increased since the beginning of the 21st century. Calving from floating ice tongues that buttress these outlets can accelerate ice flow and discharge of grounded ice. However, little is known about the dynamic impact of ice tongue loss in Greenland compared to ice shelf collapse in Antarctica. The rapidly flowing (∼1000ma -1 ) Petermann Glacier in northwest Greenland has one of the ice sheet's last remaining ice tongues, but it lost ∼50%-60% (∼40 km in length) of this tongue via two large calving events in 2010 and 2012. The glacier showed a limited velocity response to these calving events, but it is unclear how sensitive it is to future ice tongue loss. Here, we use an ice flow model (Úa) to assess the instantaneous velocity response of Petermann Glacier to past and future calving events. Our results confirm that the glacier was dynamically insensitive to large calving events in 2010 and 2012 (10% annual acceleration). We then simulate the future loss of similarly sized sections to the 2012 calving event (∼8km long) of the ice tongue back to the grounding line. We conclude that thin, soft sections of the ice tongue 12 km away from the grounding line provide little frontal buttressing, and removing them is unlikely to significantly increase ice velocity or discharge. However, once calving removes ice within 12 km of the grounding line, loss of these thicker and stiffer sections of ice tongue could perturb stresses at the grounding line enough to substantially increase inland flow speeds (∼900-1), grounded ice discharge, and Petermann Glacier's contribution to global sea level rise. © 2018 Author(s).
学科领域	discharge; floating ice; future prospect; glacial history; grounding line; ice flow; ice shelf; iceberg calving; sea level change; twenty first century; velocity profile; Arctic; Greenland; Greenland Ice Sheet; Petermann Glacier
语种	英语
scopus关键词	discharge; floating ice; future prospect; glacial history; grounding line; ice flow; ice shelf; iceberg calving; sea level change; twenty first century; velocity profile; Arctic; Greenland; Greenland Ice Sheet; Petermann Glacier
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/119012
作者单位	School of Geography Politics, and Sociology, Newcastle University, Newcastle upon Tyne, NE1 7RU, United Kingdom; Department of Geography and Environmental Sciences, Northumbria University, Newcastle upon Tyne, NE1 8ST, United Kingdom; Department of Geography, Durham University, Durham, DH1 3LE, United Kingdom
推荐引用方式 GB/T 7714	Hill E.A.,Hilmar Gudmundsson G.,Rachel Carr J.,et al. Velocity response of Petermann Glacier, northwest Greenland, to past and future calving events[J],2018,12(12).
APA	Hill E.A.,Hilmar Gudmundsson G.,Rachel Carr J.,&Stokes C.R..(2018).Velocity response of Petermann Glacier, northwest Greenland, to past and future calving events.Cryosphere,12(12).
MLA	Hill E.A.,et al."Velocity response of Petermann Glacier, northwest Greenland, to past and future calving events".Cryosphere 12.12(2018).