Reversible ice sheet thinning in the Amundsen Sea Embayment during the Late Holocene
Reversible ice sheet thinning in the Amundsen Sea Embayment during the Late Holocene
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DOI：
10.5194/tc-17-1787-2023
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发表时间：
2023-04-28
期刊：
影响因子：
5.2
通讯作者：
Woodward, John
中科院分区：
文献类型：
--
作者：
Balco, Greg;Brown, Nathan;Woodward, John
冰下基岩岩芯中的宇宙成因核素浓度表明，在过去的几千年里，位于思韦茨冰川和波普冰川之间的西南极冰盖（WAIS）比现在至少薄35米，然后加厚。这一点很重要，因为人们担心，阿蒙森海湾这些冰川和附近冰川目前的变薄和接地线退缩可能不可逆转地导致WAIS大部分地区的冰川消退，在几十年至几个世纪内，海平面将上升分米至米级。过去在类似但不完全相同的气候条件下发生的冰盖变薄事件并非不可逆转。我们建议，过去的变薄增厚周期是由于冰川均衡反弹反馈，类似于调用作为一个可能的稳定机制，目前接地线撤退，其中均衡抬升引起的早全新世变薄导致相对海平面下降有利于接地线前进。
Cosmogenic-nuclide concentrations in subglacial bedrock cores show that the West Antarctic Ice Sheet (WAIS) at a site between Thwaites and Pope glaciers was at least 35 m thinner than present in the past several thousand years and then subsequently thickened. This is important because of concern that present thinning and grounding line retreat at these and nearby glaciers in the Amundsen Sea Embayment may irreversibly lead to deglaciation of significant portions of the WAIS, with decimeter- to meter-scale sea level rise within decades to centuries. A past episode of ice sheet thinning that took place in a similar, although not identical, climate was not irreversible. We propose that the past thinning-thickening cycle was due to a glacioisostatic rebound feedback, similar to that invoked as a possible stabilizing mechanism for current grounding line retreat, in which isostatic uplift caused by Early Holocene thinning led to relative sea level fall favoring grounding line advance.