气候变化领域集成服务门户(CCPortal): Supraglacial lake drainage at a fast-flowing Greenlandic outlet glacier

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DOI	10.1073/pnas.1913685116
	Supraglacial lake drainage at a fast-flowing Greenlandic outlet glacier
	Chudley T.R.; Christoffersen P.; Doyle S.H.; Bougamont M.; Schoonman C.M.; Hubbard B.; James M.R.
发表日期	2019
ISSN	0027-8424
起始页码	25468
结束页码	25477
卷号	116 期号:51
英文摘要	Supraglacial lake drainage events influence Greenland Ice Sheet dynamics on hourly to interannual timescales. However, direct observations are rare, and, to date, no in situ studies exist from fast-flowing sectors of the ice sheet. Here, we present observations of a rapid lake drainage event at Store Glacier, west Greenland, in 2018. The drainage event transported 4.8 × 106 m3 of meltwater to the glacier bed in ∼5 h, reducing the lake to a third of its original volume. During drainage, the local ice surface rose by 0.55 m, and surface velocity increased from 2.0 m·d−1 to 5.3 m·d−1. Dynamic responses were greatest ∼4 km downstream from the lake, which we interpret as an area of transient water storage constrained by basal topography. Drainage initiated, without any precursory trigger, when the lake expanded and reactivated a preexisting fracture that had been responsible for a drainage event 1 y earlier. Since formation, this fracture had advected ∼500 m from the lake’s deepest point, meaning the lake did not fully drain. Partial drainage events have previously been assumed to occur slowly via lake overtopping, with a comparatively small dynamic influence. In contrast, our findings show that partial drainage events can be caused by hydrofracture, producing new hydrological connections that continue to concentrate the supply of surface meltwater to the bed of the ice sheet throughout the melt season. Our findings therefore indicate that the quantity and resultant dynamic influence of rapid lake drainages are likely being underestimated. © 2019 National Academy of Sciences. All rights reserved.
英文关键词	Glaciology; Greenland; Hydrology; Ice sheets; Lakes
语种	英语
scopus关键词	Article; comparative study; deglaciation; glaciation; Greenland; ice sheet; lake ecosystem; priority journal; supraglacial lake drainage; surface water hydrology; topography; 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/158858
作者单位	Chudley, T.R., Scott Polar Research Institute, University of Cambridge, Cambridge, CB2 1ER, United Kingdom; Christoffersen, P., Scott Polar Research Institute, University of Cambridge, Cambridge, CB2 1ER, United Kingdom; Doyle, S.H., Centre for Glaciology, Department of Geography and Earth Sciences, Aberystwyth University, Aberystwyth, SY23 3DB, United Kingdom; Bougamont, M., Scott Polar Research Institute, University of Cambridge, Cambridge, CB2 1ER, United Kingdom; Schoonman, C.M., Scott Polar Research Institute, University of Cambridge, Cambridge, CB2 1ER, United Kingdom; Hubbard, B., Centre for Glaciology, Department of Geography and Earth Sciences, Aberystwyth University, Aberystwyth, SY23 3DB, United Kingdom; James, M.R., Lancaster Environment Centre, University of Lancaster, Lancaster, LA1 4YQ, United Kingdom
推荐引用方式 GB/T 7714	Chudley T.R.,Christoffersen P.,Doyle S.H.,et al. Supraglacial lake drainage at a fast-flowing Greenlandic outlet glacier[J],2019,116(51).
APA	Chudley T.R..,Christoffersen P..,Doyle S.H..,Bougamont M..,Schoonman C.M..,...&James M.R..(2019).Supraglacial lake drainage at a fast-flowing Greenlandic outlet glacier.Proceedings of the National Academy of Sciences of the United States of America,116(51).
MLA	Chudley T.R.,et al."Supraglacial lake drainage at a fast-flowing Greenlandic outlet glacier".Proceedings of the National Academy of Sciences of the United States of America 116.51(2019).