Suppressed basal melting in the eastern Thwaites Glacier grounding zone.
Suppressed basal melting in the eastern Thwaites Glacier grounding zone.
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DOI：
10.1038/s41586-022-05586-0
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发表时间：
2023-02
期刊：
影响因子：
64.8
通讯作者：
Makinson, Keith
中科院分区：
文献类型：
--
作者：
Davis, Peter E. D.;Nicholls, Keith W.;Holland, David M.;Schmidt, Britney E.;Washam, Peter;Riverman, Kiya L.;Arthern, Robert J.;Vankova, Irena;Eayrs, Clare;Smith, James A.;Anker, Paul G. D.;Mullen, Andrew D.;Dichek, Daniel;Lawrence, Justin D.;Meister, Matthew M.;Clyne, Elisabeth;Basinski-Ferris, Aurora;Rignot, Eric;Queste, Bastien Y.;Boehme, Lars;Heywood, Karen J.;Anandakrishnan, Sridhar;Makinson, Keith
斯韦茨冰川是南极洲变化最快的冰-海系统之一。斯韦茨冰川集水区内的大部分冰盖位于海平面以下的基岩上，这些基岩深入内陆，因此很容易发生快速和不可逆转的冰损失，这可能使全球海平面上升半米以上。冰损失的速度和程度，以及它是否不可逆转地继续下去，是由海洋条件和斯韦茨冰川第一次漂浮的地面区域内的基底融化决定的，这两个因素在很大程度上都是未知的。在这里，我们显示，使用从热水钻取孔的观察，接地区的思韦茨东冰架（TEIS）的特点是温暖和高度稳定的水柱，温度大大高于原位冰点。尽管这些温暖的条件下，低流速和强大的密度分层在冰-海洋边界层积极限制垂直混合的热量向冰的基础，导致强烈抑制基底融化。我们的研究结果表明，用于产生海平面预测的冰架基底融化的典型模型不能再现观察到的融化率下，这一至关重要的冰川，快速和可能不稳定的接地线撤退可能与相对温和的基底融化率。尽管从热水钻孔进入孔观察显示温暖的海洋沃茨Thwaites冰川东部冰架下，由于低流速和强密度分层的基础融化率被强烈抑制。
Thwaites Glacier is one of the fastest-changing ice–ocean systems in Antarctica. Much of the ice sheet within the catchment of Thwaites Glacier is grounded below sea level on bedrock that deepens inland, making it susceptible to rapid and irreversible ice loss that could raise the global sea level by more than half a metre. The rate and extent of ice loss, and whether it proceeds irreversibly, are set by the ocean conditions and basal melting within the grounding-zone region where Thwaites Glacier first goes afloat, both of which are largely unknown. Here we show—using observations from a hot-water-drilled access hole—that the grounding zone of Thwaites Eastern Ice Shelf (TEIS) is characterized by a warm and highly stable water column with temperatures substantially higher than the in situ freezing point. Despite these warm conditions, low current speeds and strong density stratification in the ice–ocean boundary layer actively restrict the vertical mixing of heat towards the ice base, resulting in strongly suppressed basal melting. Our results demonstrate that the canonical model of ice-shelf basal melting used to generate sea-level projections cannot reproduce observed melt rates beneath this critically important glacier, and that rapid and possibly unstable grounding-line retreat may be associated with relatively modest basal melt rates. Despite observations from a hot-water-drilled access hole showing warm ocean waters beneath Thwaites Glacier Eastern Ice Shelf, the basal melt rate is strongly suppressed due to the low current speeds and strong density stratification.
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影响因子：
3.6
作者：
Davis, Peter E. D.;Nicholls, Keith W.
通讯作者：
Nicholls, Keith W.
DOI：
10.1073/pnas.1512482112
发表时间：
2015-11-17
影响因子：
11.1
作者：
Feldmann, Johannes;Levermann, Anders
通讯作者：
Levermann, Anders
影响因子：
5.2
作者：
Alley, Karen E.;Wild, Christian T.;Dunmire, Devon
通讯作者：
Dunmire, Devon
影响因子：
3.6
作者：
Begeman, Carolyn Branecky;Tulaczyk, Slawek M.;King, Matt A.
通讯作者：
King, Matt A.
影响因子：
5.2
作者：
Malczyk, G.;Gourmelen, N.;Nagler, T.
通讯作者：
Nagler, T.