DOI: 10.5194/tc-8-867-2014
Scopus记录号: 2-s2.0-84901434352
论文题名: Transition of flow regime along a marine-terminating outlet glacier in East Antarctica
作者: Callens D ; , Matsuoka K ; , Steinhage D ; , Smith B ; , Witrant E ; , Pattyn F
刊名: Cryosphere
ISSN: 19940416
出版年: 2014
卷: 8, 期: 3 起始页码: 867
结束页码: 875
语种: 英语
英文关键词: 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
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. Citation statistics:
资源类型: 期刊论文
标识符: http://119.78.100.158/handle/2HF3EXSE/74849
Appears in Collections: 影响、适应和脆弱性 气候变化与战略
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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
Recommended Citation:
Callens D,, Matsuoka K,, Steinhage D,et al. Transition of flow regime along a marine-terminating outlet glacier in East Antarctica[J]. Cryosphere,2014-01-01,8(3)