Evidence for the stability of the West Antarctic Ice Sheet divide for 1.4 million years.
Evidence for the stability of the West Antarctic Ice Sheet divide for 1.4 million years.
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DOI：
10.1038/ncomms10325
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发表时间：
2016-02-03
影响因子：
16.6
通讯作者：
Sugden DE
中科院分区：
文献类型：
--
作者：
Hein AS;Woodward J;Marrero SM;Dunning SA;Steig EJ;Freeman SP;Stuart FM;Winter K;Westoby MJ;Sugden DE
南极西部冰盖过去的波动具有根本意义，因为南极西部冰盖未来可能崩溃，从而导致全球海平面上升。然而，过去间冰期冰盖的结构和稳定性仍然不确定。在这里，我们提出了来自南埃尔斯沃思山脉的地貌学证据和多重宇宙成因核素数据，表明至少在过去的140万年里，WAIS的分裂在位置和厚度上只有适度的波动。冰期-间冰期旋回期间的波动似乎叠加在冰面相对于山脉下降的长期轨迹上。这意味着，以埃尔斯沃斯-惠特莫尔高地为中心的区域性冰盖可能在更新世的温暖期中幸存下来。如果是这样的话，它将把WAIS对间冰期全球海平面上升的贡献限制在比现在高3.3米左右。由于缺乏历史证据，预测南极西部冰盖对未来变暖的反应受到阻碍。在这里，基于来自埃尔斯沃思山脉沉积物的地貌证据和宇宙成因定年，作者表明，至少有一个区域冰盖在更新世间冰期旋回中幸存下来。
Past fluctuations of the West Antarctic Ice Sheet (WAIS) are of fundamental interest because of the possibility of WAIS collapse in the future and a consequent rise in global sea level. However, the configuration and stability of the ice sheet during past interglacial periods remains uncertain. Here we present geomorphological evidence and multiple cosmogenic nuclide data from the southern Ellsworth Mountains to suggest that the divide of the WAIS has fluctuated only modestly in location and thickness for at least the last 1.4 million years. Fluctuations during glacial–interglacial cycles appear superimposed on a long-term trajectory of ice-surface lowering relative to the mountains. This implies that as a minimum, a regional ice sheet centred on the Ellsworth-Whitmore uplands may have survived Pleistocene warm periods. If so, it constrains the WAIS contribution to global sea level rise during interglacials to about 3.3 m above present. Predicting the West Antarctic Ice Sheet's response to future warming is hindered by a lack of historical evidence. Here, based on geomorphological evidence from and cosmogenic dating of Ellsworth Mountains' deposits, the authors show that at least a regional ice sheet survived Pleistocene interglacial cycles.