Deformation and failure of the ice bridge on the Wilkins Ice Shelf, Antarctica
Deformation and failure of the ice bridge on the Wilkins Ice Shelf, Antarctica
复制标题
南极洲威尔金斯冰架上冰桥的变形和破坏
DOI：
10.3189/172756410791392709
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发表时间：
2010
影响因子：
2.9
通讯作者：
W. J. van de Berg
中科院分区：
文献类型：
--
作者：
A. Humbert;D. Gross;R. Müller;M. Braun;R. V. D. van de Wal;M. R. van den Broeke;D. Vaughan;W. J. van de Berg
摘要2009年4月初，一座连接南极洲威尔金斯冰架和两个封闭岛屿的浮冰桥最终倒塌。在坍塌前一个月，我们通过卫星图像和现场GPS站观察到冰桥的变形。TerraSAR-X图像（在条带模式下获得）被用于编制时间序列。冰桥在其西北部（西风）弯曲最强烈，而北方端（靠近夏科岛）则向东北方向移动。在南部，冰桥经历了平行于其长轴的压缩应变。GPS定位数据是从2009年1月19日起在冰桥最西端偏南一点的地方采集的。这些数据的分析表明，运动的周期性和单调性成分。气象数据和对天气预报模式输出的重新分析表明，东风是造成周期运动的原因。特别是，风对东部地区的粗糙冰混合物产生的压力对冰桥施加了巨大的压力。冰桥的倒塌始于与冰桥长轴平行的南段裂缝的形成，并导致南段的破碎。最后，只有900米宽的最西面部分破裂了。许多小冰山的形成释放了大于125 ×106 J的能量。
Abstract A narrow bridge of floating ice that connected the Wilkins Ice Shelf, Antarctica, to two confining islands eventually collapsed in early April 2009. In the month preceding the collapse, we observed deformation of the ice bridge by means of satellite imagery and from an in situ GPS station. TerraSAR-X images (acquired in stripmap mode) were used to compile a time series. The ice bridge bent most strongly in its narrowest part (westerly), while the northern end (near Charcot Island) shifted in a northeasterly direction. In the south, the ice bridge experienced compressive strain parallel to its long axis. GPS position data were acquired a little south of the narrowest part of the ice bridge from 19 January 2009. Analysis of these data showed both cyclic and monotonic components of motion. Meteorological data and re-analysis of the output of weather-prediction models indicated that easterly winds were responsible for the cyclic motion component. In particular, wind stress on the rough ice melange that occupied the area to the east exerted significant pressure on the ice bridge. The collapse of the ice bridge began with crack formation in the southern section parallel to the long axis of the ice bridge and led to shattering of the southern part. Ultimately, the narrowest part, only 900 m wide, ruptured. The formation of many small icebergs released energy of >125 ×106 J.