DOI: 10.5194/tc-11-1199-2017
Scopus记录号: 2-s2.0-85019265751
论文题名: Dynamic changes on the Wilkins Ice Shelf during the 2006-2009 retreat derived from satellite observations
作者: Rankl M ; , Jakob Fürst J ; , Humbert A ; , Holger Braun M
刊名: Cryosphere
ISSN: 19940416
出版年: 2017
卷: 11, 期: 3 起始页码: 1199
结束页码: 1211
语种: 英语
英文关键词: fracture
; glacier dynamics
; glacier retreat
; ice breakup
; ice shelf
; satellite data
; spatial analysis
; spatiotemporal analysis
; strain rate
; stress field
; synthetic aperture radar
; time series
; Antarctic Peninsula
; Antarctica
; West Antarctica
; Wilkins Ice Shelf
英文摘要: The vast ice shelves around Antarctica provide significant restraint to the outflow from adjacent tributary glaciers. This important buttressing effect became apparent in the last decades, when outlet glaciers accelerated considerably after several ice shelves were lost around the Antarctic Peninsula (AP). The present study aims to assess dynamic changes on the Wilkins Ice Shelf (WIS) during different stages of ice-front retreat and partial collapse between early 2008 and 2009. The total ice-shelf area lost in these events was 2135 ± 75 km2 (∼ 15 % of the ice-shelf area relative to 2007). Here, we use time series of synthetic aperture radar (SAR) satellite observations (1994-1996, 2006-2010) in order to derive variations in surface-flow speed from intensity-offset tracking. Spatial patterns of horizontal strain-rate, stress and stress-flow angle distributions are determined during different ice-front retreat stages. Prior to the final break up of an ice bridge in 2008, a strong speed up is observed, which is also discernible from other derived quantities. We identify areas that are important for buttressing and areas prone to fracturing using in-flow and first principal strain rates as well as principal stress components. Further propagation of fractures can be explained as the first principal components of strain rates and stresses exceed documented threshold values. Positive second principal stresses are another scale-free indicator for ice-shelf areas, where fractures preferentially open. Second principal strain rates are found to be insensitive to ice-front retreat or fracturing. Changes in stress-flow angles highlight similar areas as the in-flow strain rates but are difficult to interpret. Our study reveals the large potential of modern SAR satellite time series to better understand dynamic and structural changes during ice-shelf retreat but also points to uncertainties introduced by the methods applied. © 2017 Author(s). Citation statistics:
资源类型: 期刊论文
标识符: http://119.78.100.158/handle/2HF3EXSE/75554
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: Friedrich-Alexander Universität Erlangen-Nürnberg, Institute of Geography, Erlangen, Germany; Alfred Wegener Institute, Helmholtz Centre for Polar and Marine Research, Glaciology Section, Bremerhaven, Germany; University of Bremen, Department of Geosciences, Bremen, Germany
Recommended Citation:
Rankl M,, Jakob Fürst J,, Humbert A,et al. Dynamic changes on the Wilkins Ice Shelf during the 2006-2009 retreat derived from satellite observations[J]. Cryosphere,2017-01-01,11(3)