The sensitivity of Cook Glacier, East Antarctica, to changes in ice-shelf extent and grounding-line position
The sensitivity of Cook Glacier, East Antarctica, to changes in ice-shelf extent and grounding-line position
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DOI：
10.1017/jog.2021.106
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发表时间：
2021-10-06
影响因子：
3.4
通讯作者：
Jamieson, Stewart S. R.
中科院分区：
文献类型：
--
作者：
Jordan, James R.;Gudmundsson, G. Hilmar;Jamieson, Stewart S. R.
南极洲东部的威尔克斯冰下盆地含有相当于全球平均海平面上升3-4米的冰，主要由库克冰川排出。令人关切的是，最近的观测（自20世纪70年代以来）显示，库克冰川东部和西部的接地线上的冰速加快。在这里，我们使用一个数值冰流模型（Ua）来模拟库克冰川终点观测到的变化的瞬时影响，以了解这些变化和最近观察到的冰加速度之间的联系。模拟表明，库克西部的加速是由于在20世纪70年代的退冰锋的位置，潜在的增强接地线撤退，而库克东部的加速可能是由于冰架变薄和接地线撤退在20世纪90年代中期。此外，我们表明，在库克东部的瞬时冰流量将增加高达85%，如果整个冰架被删除，它从一个钉扎点ungrounds;和库克西部的流量可能会增加-300%，如果其接地线后退10公里。
The Wilkes Subglacial Basin in East Antarctica contains ice equivalent to 3-4 m of global mean sea level rise and is primarily drained by Cook Glacier. Of concern is that recent observations (since the 1970s) show an acceleration in ice speed over the grounding line of both the Eastern and Western portions of Cook Glacier. Here, we use a numerical ice-flow model (Ua) to simulate the instantaneous effects of observed changes at the terminus of Cook Glacier in order to understand the link between these changes and recently observed ice acceleration. Simulations suggest that the acceleration of Cook West was caused by a retreat in calvingfront position in the 1970s, potentially enhanced by grounding-line retreat, while acceleration of Cook East was likely caused by ice-shelf thinning and grounding-line retreat in the mid1990s. Moreover, we show that the instantaneous ice discharge at Cook East would increase by up to 85% if the whole ice shelf is removed and it ungrounds from a pinning point; and that the discharge at Cook West could increase by -300% if its grounding line retreated by 10 km.