The safety band of Antarctic ice shelves
The safety band of Antarctic ice shelves
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DOI：
10.1038/nclimate2912
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发表时间：
2016-05-01
影响因子：
30.7
通讯作者：
Gagliardini, Olivier
中科院分区：
文献类型：
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作者：
Fuerst, Johannes Jakob;Durand, Gael;Gagliardini, Olivier
沿着南极冰盖海岸沿着的浮冰架限制了上游沉积冰的外流（1，2）。过去的冰架衰退和破裂表明，这些冰架的移除加速了外流（3，4），这增加了海平面的上升。在预测未来外流的一个关键问题是量化的程度，可能先决条件其他动态的后果，并导致冰架约束的损失的产犊。在这里，我们描绘了锋面区域，我们标记为“被动陆架冰”，可以删除没有重大的动态影响，整个大陆的对比结果。阿蒙森海和别林斯高晋海的冰架具有有限的或几乎没有“被动”部分，这意味着当前冰架前缘的进一步后退将产生重要的动态后果。这一地区特别脆弱，因为冰架在过去20年里一直在高速变薄，而且上游的接地冰位于向后倾斜的河床上，这是海洋冰盖不稳定的先决条件（6，7）。与这些冰架相反，威德尔海的拉森C冰架显示出一个大的“被动”锋面区域，这表明一个巨大的扁平冰山即将崩解不太可能立即产生太多的动态变化。
The floating ice shelves along the seaboard of the Antarctic ice sheet restrain the outflow of upstream grounded ice(1,2). Removal of these ice shelves, as shown by past ice-shelf recession and break-up, accelerates the outflow(3,4), which adds to sea-level rise. A key question in predicting future outflow is to quantify the extent of calving that might precondition other dynamic consequences and lead to loss of ice-shelf restraint. Here we delineate frontal areas that we label as 'passive shelf ice' and that can be removed without major dynamic implications, with contrasting results across the continent. The ice shelves in the Amundsen and Bellingshausen seas have limited or almost no 'passive' portion, which implies that further retreat of current ice-shelf fronts will yield important dynamic consequences. This region is particularly vulnerable as ice shelves have been thinning at high rates for two decades' and as upstream grounded ice rests on a backward sloping bed, a precondition to marine ice-sheet instability(6,7). In contrast to these ice shelves, Larsen C Ice Shelf, in the Weddell Sea, exhibits a large 'passive' frontal area, suggesting that the imminent calving of a vast tabular iceberg(8) will be unlikely to instantly produce much dynamic change.