Accelerated ice shelf rifting and retreat at Pine Island Glacier, West Antarctica
Accelerated ice shelf rifting and retreat at Pine Island Glacier, West Antarctica
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DOI：
10.1002/2016gl071360
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发表时间：
2016-11-28
影响因子：
5.2
通讯作者：
Bassis, Jeremy N.
中科院分区：
文献类型：
--
作者：
Jeong, Seongsu;Howat, Ian M.;Bassis, Jeremy N.
在过去的几十年里，松岛冰川经历了几次重大的冰山崩解事件。这通常发生在严重断裂的剪切边缘的裂谷沿冰架宽度传播时。这种类型的冰裂在极地冰架上很常见，与海洋冰动力强迫没有明确的联系。相比之下，我们报告了最近从冰架中心的基底裂缝开始的多个裂缝的发展，导致比以前观察到的更远的冰川崩解。与裂谷形成同时发生的是填满北部剪切边缘的冰杂岩的突然崩解，导致冰盖从该边缘分离。对冰速度的研究表明，这种内部裂谷是由混合岩崩解引起的冰架应力变化和基底裂缝内的加速融化共同造成的，这两者都可能与海洋强迫有关。
Pine Island Glacier has undergone several major iceberg calving events over the past decades. These typically occurred when a rift at the heavily fractured shear margin propagated across the width of the ice shelf. This type of calving is common on polar ice shelves, with no clear connection to ocean-ice dynamic forcing. In contrast, we report on the recent development of multiple rifts initiating from basal crevasses in the center of the ice shelf, resulted in calving further upglacier than previously observed. Coincident with rift formation was the sudden disintegration of the ice melange that filled the northern shear margin, resulting in ice sheet detachment from this margin. Examination of ice velocity suggests that this internal rifting resulted from the combination of a change in ice shelf stress regime caused by disintegration of the melange and intensified melting within basal crevasses, both of which may be linked to ocean forcing.