气候变化领域集成服务门户(CCPortal): Simulating the roles of crevasse routing of surface water and basal friction on the surge evolution of Basin 3, Austfonna ice cap

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DOI	10.5194/tc-12-1563-2018
	Simulating the roles of crevasse routing of surface water and basal friction on the surge evolution of Basin 3, Austfonna ice cap
	Gong Y.; Zwinger T.; Åström J.; Altena B.; Schellenberger T.; Gladstone R.; Moore J.C.
发表日期	2018
ISSN	19940416
卷号	12 期号:5
英文摘要	The marine-terminating outlet in Basin 3, Austfonna ice cap, has been accelerating since the mid-1990s. Stepwise multi-annual acceleration associated with seasonal summer speed-up events was observed before the outlet entered the basin-wide surge in autumn 2012. We used multiple numerical models to explore hydrologic activation mechanisms for the surge behaviour. A continuum ice dynamic model was used to invert basal friction coefficient distributions using the control method and observed surface velocity data between April 2012 and July 2014. This has provided input to a discrete element model capable of simulating individual crevasses, with the aim of finding locations where meltwater entered the glacier during the summer and reached the bed. The possible flow paths of surface meltwater reaching the glacier bed as well as those of meltwater produced at the bed were calculated according to the gradient of the hydraulic potential. The inverted friction coefficients show the "unplugging" of the stagnant ice front and expansion of low-friction regions before the surge reached its peak velocity in January 2013. Crevasse distribution reflects the basal friction pattern to a high degree. The meltwater reaches the bed through the crevasses located above the margins of the subglacial valley and the basal melt that is generated mainly by frictional heating flows either to the fast-flowing units or potentially accumulates in an overdeepened region. Based on these results, the mechanisms facilitated by basal meltwater production, crevasse opening and the routing of meltwater to the bed are discussed for the surge in Basin 3. © Author(s) 2018.
学科领域	basal ice; basal melting; basin evolution; crevasse; friction; glacial hydrology; ice cap; meltwater; numerical model; seasonal variation; simulation; subglacial environment; summer; surface water; valley; Arctic; Austfonna; Nordaustlandet; Svalbard; Svalbard and Jan Mayen
语种	英语
scopus关键词	basal ice; basal melting; basin evolution; crevasse; friction; glacial hydrology; ice cap; meltwater; numerical model; seasonal variation; simulation; subglacial environment; summer; surface water; valley; Arctic; Austfonna; Nordaustlandet; Svalbard; Svalbard and Jan Mayen
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/119157
作者单位	Institute for Atmospheric and Earth System Research, University of Helsinki, Helsinki, 00014, Finland; CSC - IT Center for Science Ltd., Espoo, 02101, Finland; Department of Geosciences, University of Oslo, Oslo, 0371, Norway; Arctic Center, University of Lapland, Rovaniemi, 96100, Finland; College of Global Change and Earth System Science, Beijing Normal University, Beijing, 100875, China
推荐引用方式 GB/T 7714	Gong Y.,Zwinger T.,Åström J.,et al. Simulating the roles of crevasse routing of surface water and basal friction on the surge evolution of Basin 3, Austfonna ice cap[J],2018,12(5).
APA	Gong Y..,Zwinger T..,Åström J..,Altena B..,Schellenberger T..,...&Moore J.C..(2018).Simulating the roles of crevasse routing of surface water and basal friction on the surge evolution of Basin 3, Austfonna ice cap.Cryosphere,12(5).
MLA	Gong Y.,et al."Simulating the roles of crevasse routing of surface water and basal friction on the surge evolution of Basin 3, Austfonna ice cap".Cryosphere 12.5(2018).