Low post-glacial rebound rates in the Weddell Sea due to Late Holocene ice-sheet readvance
Low post-glacial rebound rates in the Weddell Sea due to Late Holocene ice-sheet readvance
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DOI：
10.1016/j.epsl.2014.12.039
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发表时间：
2015-03-01
影响因子：
5.3
通讯作者：
King, Matt A.
中科院分区：
文献类型：
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作者：
Bradley, Sarah L.;Hindmarsh, Richard C. A.;King, Matt A.
许多冰盖重建假设南极西部冰盖在全新世是单调的退缩，但越来越多的冰川学观测推断，冰盖的某些部分可能在退缩到今天的边缘之后重新前进。威德尔海地区的研究进展可以解决两个突出的问题：(i)目前广泛出现的看似稳定的冰流，其基础是内陆加深的河床；（ii）冰川均衡调整模式无法与当今的隆升速率相匹配。通过将一系列冰荷载历史（包括一个预估）与一个冰川均衡调整模型相结合，我们报告了对当今隆升率预测的重大改进，包括调和一个有问题的陆地下沉观测。我们认为，目前的接地线后退发生在床层较低时，此后均衡恢复导致变浅，冰盖重新接地和前进。根据我们的负荷模型，在明显不稳定的反向床坡配置中，接地线的矛盾存在可以通过调用不稳定推进过程来解决。(C) 2014年作者。Elsevier B.V.出版
Many ice-sheet reconstructions assume monotonic Holocene retreat for the West Antarctic Ice Sheet, but an increasing number of glaciological observations infer that some portions of the ice sheet may be readvancing, following retreat behind the present-day margin. A readvance in the Weddell Sea region can reconcile two outstanding problems: (i) the present-day widespread occurrence of seemingly stable ice streams grounded on beds that deepen inland; and (ii) the inability of models of glacial isostatic adjustment to match present-day uplift rates. By combining a suite of ice loading histories that include a readvance with a model of glacial isostatic adjustment we report substantial improvements to predictions of present-day uplift rates, including reconciling one problematic observation of land sinking. We suggest retreat behind present grounding lines occurred when the bed was lower, and isostatic recovery has since led to shallowing, ice sheet re-grounding and readvance. The paradoxical existence of grounding lines in apparently unstable configurations on reverse bed slopes may be resolved by invoking the process of unstable advance, in accordance with our load modelling. (C) 2014 The Authors. Published by Elsevier B.V.