Mid-Holocene pulse of thinning in the Weddell Sea sector of the West Antarctic ice sheet.
Mid-Holocene pulse of thinning in the Weddell Sea sector of the West Antarctic ice sheet.
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DOI：
10.1038/ncomms12511
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发表时间：
2016-08-22
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;Marrero SM;Woodward J;Dunning SA;Winter K;Westoby MJ;Freeman SP;Shanks RP;Sugden DE
建立末次盛冰期以来西南极冰盖变薄的轨迹对于解决冰盖稳定性和全球海平面变化问题具有重要意义。在这里，我们提出了详细的地貌和宇宙成因的核素数据，从南部埃尔斯沃思山脉的心脏地带的威德尔海海湾的冰盖，增加降雪，直到全新世早期的滋养，接近其末次冰期的厚度在10万年。在6.5-3.5 ka时，一个快速变薄的脉冲导致冰高度下降了1400 m，达到目前的水平，并可能导致全球海平面上升1.4-2 m。这些结果表明，威德尔海部门的WAIS贡献不大，晚冰期脉冲海平面上升，但参与了中全新世上升。阶梯式下降被认为反映了接地线撤退到大力神湾引发的海洋下沉。 西南极冰盖（WAIS）融化对全球海平面上升的确切贡献仍然是个谜。在这里，作者生成了威德尔海海湾的冰盖变薄历史，并提出WAIS的这一部分促成了全新世中期，而不是晚冰期海平面上升。
Establishing the trajectory of thinning of the West Antarctic ice sheet (WAIS) since the last glacial maximum (LGM) is important for addressing questions concerning ice sheet (in)stability and changes in global sea level. Here we present detailed geomorphological and cosmogenic nuclide data from the southern Ellsworth Mountains in the heart of the Weddell Sea embayment that suggest the ice sheet, nourished by increased snowfall until the early Holocene, was close to its LGM thickness at 10 ka. A pulse of rapid thinning caused the ice elevation to fall ∼400 m to the present level at 6.5–3.5 ka, and could have contributed 1.4–2 m to global sea-level rise. These results imply that the Weddell Sea sector of the WAIS contributed little to late-glacial pulses in sea-level rise but was involved in mid-Holocene rises. The stepped decline is argued to reflect marine downdraw triggered by grounding line retreat into Hercules Inlet. The precise contribution of the West Antarctic Ice Sheet (WAIS) melt to global sea-level rise remains enigmatic. Here, the authors generate an ice sheet thinning history for the Weddell Sea embayment and propose that this sector of the WAIS contributed to mid-Holocene, rather than late-glacial sea-level rise.