Retreat of Pine Island Glacier controlled by marine ice-sheet instability
Retreat of Pine Island Glacier controlled by marine ice-sheet instability
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DOI：
10.1038/nclimate2094
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发表时间：
2014-02-01
影响因子：
30.7
通讯作者：
Le Brocq, A. M.
中科院分区：
文献类型：
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作者：
Favier, L.;Durand, G.;Le Brocq, A. M.
在过去的40年里，南极洲西部的松岛冰川以加速的速度变薄（1-3），因此目前它是南极洲海平面上升的最大单一因素（4）。近年来，将陆地冰盖与浮冰架分开的接地线已经后退了数十公里（5）。目前，接地线正穿过远低于海平面的后退基岩斜坡，这增加了冰川易受海洋冰盖不稳定机制影响的可能性（6-8）。在这里，使用三个国家的最先进的冰流模型（9-11），我们表明，松岛冰川的接地线可能是从事一个不稳定的40公里的撤退。在我们的模拟过程中，相关的质量损失从1992-2011年期间观察到的20 Gt yr（-1）的平均值（4）大幅增加，达到或超过100 Gt yr（-1），相当于在接下来的20年中海平面上升3.5- 10 mm。从那时起，质量损失一直在上升，范围从60到120 Gt yr（-1）。
Over the past 40 years Pine Island Glacier in West Antarctica has thinned at an accelerating rate(1-3), so that at present it is the largest single contributor to sea-level rise in Antarctica(4). In recent years, the grounding line, which separates the grounded ice sheet from the floating ice shelf, has retreated by tens of kilometres(5). At present, the grounding line is crossing a retrograde bedrock slope that lies well below sea level, raising the possibility that the glacier is susceptible to the marine ice-sheet instability mechanism(6-8). Here, using three state-of-the-art ice-flow models(9-11), we show that Pine Island Glacier's grounding line is probably engaged in an unstable 40 km retreat. The associated mass loss increases substantially over the course of our simulations from the average value of 20 Gt yr(-1) observed for the 1992-2011 period(4), up to and above 100 Gt yr(-1), equivalent to 3.5-10mm eustatic sea-level rise over the following 20 years. Mass loss remains elevated from then on, ranging from 60 to 120 Gt yr(-1).