气候变化领域集成服务门户(CCPortal): Transition of flow regime along a marine-terminating outlet glacier in East Antarctica

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DOI	10.5194/tc-8-867-2014
	Transition of flow regime along a marine-terminating outlet glacier in East Antarctica
	Callens D.; Matsuoka K.; Steinhage D.; Smith B.; Witrant E.; Pattyn F.
发表日期	2014
ISSN	19940416
卷号	8 期号:3
英文摘要	We present results of a multi-methodological approach to characterize the flow regime of West Ragnhild Glacier, the widest glacier in Dronning Maud Land, Antarctica. A new airborne radar survey points to substantially thicker ice (> 2000 m) than previously thought. With a discharge estimate of 13-14 Gtyr-1, West Ragnhild Glacier thus becomes of the three major outlet glaciers in Dronning Maud Land. Its bed topography is distinct between the upstream and downstream section: in the downstream section (< 65 km upstream of the grounding line), the glacier overlies a wide and flat basin well below the sea level, while the upstream region is more mountainous. Spectral analysis of the bed topography also reveals this clear contrast and suggests that the downstream area is sediment covered. Furthermore, bed-returned power varies by 30 dB within 20 km near the bed flatness transition, suggesting that the water content at bed/ice interface increases over a short distance downstream, hence pointing to water-rich sediment. Ice flow speed observed in the downstream part of the glacier (~250myr-1) can only be explained through very low basal friction, leading to a substantial amount of basal sliding in the downstream 65 km of the glacier. All the above lines of evidence (sediment bed, wetness and basal motion) and the relatively flat grounding zone give the potential for West Ragnhild Glacier to be more sensitive to external forcing compared to other major outlet glaciers in this region, which are more stable due to their bed geometry (e.g. Shirase Glacier). © Author(s) 2014.
学科领域	airborne survey; bottom topography; flow pattern; glacier retreat; ice flow; ice thickness; radar; sea level; spectral analysis; Antarctica; East Antarctica; Queen Maud Land; Shirase Glacier
语种	英语
scopus关键词	airborne survey; bottom topography; flow pattern; glacier retreat; ice flow; ice thickness; radar; sea level; spectral analysis; Antarctica; East Antarctica; Queen Maud Land; Shirase 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/120114
作者单位	Laboratoire de Glaciologie, Université Libre de Bruxelles, Brussels, Belgium; Norwegian Polar Institute, Tromsø, Norway; Alfred-Wegener-Institut Helmholtz-Zentrum für Polar- und Meeresforschung, Bremerhaven, Germany; Applied Physics Laboratory, University of Washington, Seattle, WA, United States; GIPSA-lab, Université Joseph Fourrier, Grenoble, France
推荐引用方式 GB/T 7714	Callens D.,Matsuoka K.,Steinhage D.,et al. Transition of flow regime along a marine-terminating outlet glacier in East Antarctica[J],2014,8(3).
APA	Callens D.,Matsuoka K.,Steinhage D.,Smith B.,Witrant E.,&Pattyn F..(2014).Transition of flow regime along a marine-terminating outlet glacier in East Antarctica.Cryosphere,8(3).
MLA	Callens D.,et al."Transition of flow regime along a marine-terminating outlet glacier in East Antarctica".Cryosphere 8.3(2014).