气候变化领域集成服务门户(CCPortal): Thickness of the divide and flank of the West Antarctic Ice Sheet through the last deglaciation

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DOI	10.5194/tc-13-3061-2019
	Thickness of the divide and flank of the West Antarctic Ice Sheet through the last deglaciation
	Spector P.; Stone J.; Goehring B.
发表日期	2019
ISSN	19940416
EISSN	13
起始页码	3061
结束页码	3075
卷号	13 期号:11
英文摘要	We report cosmogenic-nuclide measurements from two isolated groups of nunataks in West Antarctica: the Pirrit Hills, located midway between the grounding line and the divide in the Weddell Sea sector, and the Whitmore Mountains, located along the Ross-Weddell divide. At the Pirrit Hills, evidence of glacial-stage ice cover extends ∼ 320m above the present ice surface. Subsequent thinning mostly occurred after ∼ 14 kyr BP, and modern ice levels were established some time after ∼ 4 kyr BP. We infer that, like at other flank sites, these changes were primarily controlled by the position of the grounding line downstream. At the Whitmore Mountains, cosmogenic 14C concentrations in bedrock surfaces demonstrate that ice there was no more than ∼ 190m thicker than present during the past ∼ 30 kyr. Combined with other constraints from West Antarctica, the 14C data imply that the divide was thicker than present for a period of less than ∼ 8 kyr within the past ∼ 15 kyr. These results are consistent with the hypothesis that the divide initially thickened due to the deglacial rise in snowfall and subsequently thinned in response to retreat of the ice-sheet margin. We use these data to evaluate several recently published ice-sheet models at the Pirrit Hills and Whitmore Mountains. Most of the models we consider do not match the observed timing and/or magnitude of thickness change at these sites. However, one model performs relatively well at both sites, which may, in part, be due to the fact that it was calibrated with geological observations of ice-thickness change from other sites in Antarctica. © Author(s) 2019.
学科领域	cosmogenic radionuclide; grounding line; ice core; ice cover; ice thickness; last deglaciation; Antarctic Ice Sheet; Antarctica; Southern Ocean; Weddell Sea; West Antarctic Ice Sheet; West Antarctica
语种	英语
scopus关键词	cosmogenic radionuclide; grounding line; ice core; ice cover; ice thickness; last deglaciation; Antarctic Ice Sheet; Antarctica; Southern Ocean; Weddell Sea; West Antarctic Ice Sheet; West Antarctica
来源期刊	The Cryosphere
文献类型	期刊论文
条目标识符	http://gcip.llas.ac.cn/handle/2XKMVOVA/118807
作者单位	Berkeley Geochronology Center, 2455 Ridge Road, Berkeley, CA, United States; Department of Earth and Space Sciences, University of Washington, Seattle, WA, United States; Department of Earth and Environmental Sciences, Tulane University, New Orleans, LA, United States
推荐引用方式 GB/T 7714	Spector P.,Stone J.,Goehring B.. Thickness of the divide and flank of the West Antarctic Ice Sheet through the last deglaciation[J],2019,13(11).
APA	Spector P.,Stone J.,&Goehring B..(2019).Thickness of the divide and flank of the West Antarctic Ice Sheet through the last deglaciation.The Cryosphere,13(11).
MLA	Spector P.,et al."Thickness of the divide and flank of the West Antarctic Ice Sheet through the last deglaciation".The Cryosphere 13.11(2019).