DOI: 10.5194/tc-12-1347-2018
Scopus记录号: 2-s2.0-85045524798
论文题名: Recent dynamic changes on Fleming Glacier after the disintegration of Wordie Ice Shelf, Antarctic Peninsula
作者: Friedl P ; , Seehaus T ; C ; , Wendt A ; , Braun M ; H ; , Höppner K
刊名: Cryosphere
ISSN: 19940416
出版年: 2018
卷: 12, 期: 4 起始页码: 1347
结束页码: 1365
语种: 英语
英文关键词: acceleration
; bottom topography
; climate change
; data set
; glacier dynamics
; grounding line
; ice shelf
; remote sensing
; sensor
; subglacial environment
; synthetic aperture radar
; upwelling
; Antarctic Peninsula
; Antarctica
; Fleming Glacier
; Marguerite Bay
; West Antarctica
; Wordie Ice Shelf
英文摘要: The Antarctic Peninsula is one of the world's regions most affected by climate change. Several ice shelves have retreated, thinned or completely disintegrated during recent decades, leading to acceleration and increased calving of their tributary glaciers. Wordie Ice Shelf, located in Marguerite Bay at the south-western side of the Antarctic Peninsula, completely disintegrated in a series of events between the 1960s and the late 1990s. We investigate the longterm dynamics (1994-2016) of Fleming Glacier after the disintegration of Wordie Ice Shelf by analysing various multisensor remote sensing data sets. We present a dense time series of synthetic aperture radar (SAR) surface velocities that reveals a rapid acceleration of Fleming Glacier in 2008 and a phase of further gradual acceleration and upstream propagation of high velocities in 2010-2011.The timing in acceleration correlates with strong upwelling events of warm circumpolar deep water (CDW) intoWordie Bay, most likely leading to increased submarine melt. This, together with continuous dynamic thinning and a deep subglacial trough with a retrograde bed slope close to the terminus probably, has induced unpinning of the glacier tongue in 2008 and gradual grounding line retreat between 2010 and 2011. Our data suggest that the glacier's grounding line had retreated by 6-9 km between 1996 and 2011, which caused ∼56 km2 of the glacier tongue to go afloat. The resulting reduction in buttressing explains a median speedup of ∼1.3md-1 (∼27 %) between 2008 and 2011, which we observed along a centre line extending between the grounding line in 1996 and ∼16 km upstream. Current median ice thinning rates (2011-2014) along profiles in areas below 1000m altitude range between ∼2.6 to 3.2ma-1 and are ∼70% higher than between 2004 and 2008. Our study shows that Fleming Glacier is far away from approaching a new equilibrium and that the glacier dynamics are not primarily controlled by the loss of the former ice shelf anymore. Currently, the tongue of Fleming Glacier is grounded in a zone of bedrock elevation between ∼-400 and-500 m. However, about 3-4 km upstream modelled bedrock topography indicates a retrograde bed which transitions into a deep trough of up to ∼-1100m at ∼10 km upstream. Hence, this endangers upstream ice masses, which can significantly increase the contribution of Fleming Glacier to sea level rise in the future. © 2018 Author(s). Citation statistics:
资源类型: 期刊论文
标识符: http://119.78.100.158/handle/2HF3EXSE/75378
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: German Remote Sensing Data Center, German Aerospace Center, Oberpfaffenhofen, Germany; Institute of Geography, Friedrich Alexander University Erlangen-Nuremberg, Erlangen, Germany; Bavarian Academy of Sciences and Humanities, Munich, Germany
Recommended Citation:
Friedl P,, Seehaus T,C,et al. Recent dynamic changes on Fleming Glacier after the disintegration of Wordie Ice Shelf, Antarctic Peninsula[J]. Cryosphere,2018-01-01,12(4)