Steep reverse bed slope at the grounding line of the Weddell Sea sector in West Antarctica
Steep reverse bed slope at the grounding line of the Weddell Sea sector in West Antarctica
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南极洲西部威德尔海区接地线的陡峭反向床坡
DOI：
10.1038/ngeo1468
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发表时间：
2012
影响因子：
18.3
通讯作者：
Ross N
中科院分区：
文献类型：
--
作者：
Ross N
南极洲西部冰盖的冰层在某些地方低于海平面1.5公里。有人认为，当冰盖的接地线后退穿过加深的河床时，可能会发生正的冰损反馈。如果应用于南极洲西部冰盖，这一过程可能会使全球海平面上升3米以上。最近，人们的注意力集中在西南极洲的西普尔海岸和阿蒙森海湾的变化上。在这里，我们目前的无线电回声探测信息从冰盖的第三部门，威德尔海海湾，揭示了一个大的冰下盆地紧接上游的接地线。逆床坡陡，40 km以上的落差约400 m。盆地底部光滑平坦，几乎没有会延迟退缩的小规模地形，这表明它已被海洋沉积物覆盖，并且之前已被冰消。在盆地的上游，界限分明的冰川雕刻峡湾与酒吧在他们的嘴证明了前冰缘的位置约200公里的内陆从现在的边缘。到目前为止的证据表明，南极洲西部冰盖的威德尔海部分一直很稳定，但根据我们的数据，我们认为该地区可能接近实质性变化的物理阈值。
The bed of the West Antarctic Ice Sheet is, in places, more than 1.5 km below sea level,. It has been suggested that a positive ice-loss feedback may occur when an ice sheet’s grounding line retreats across a deepening bed,,. Applied to the West Antarctic Ice Sheet, this process could potentially raise global sea level by more than 3 m. Hitherto, attention has focussed on changes at the Siple Coast,,and Amundsen Sea embayment,,sectors of West Antarctica. Here, we present radio-echo sounding information from the ice sheet’s third sector, the Weddell Sea embayment, that reveals a large subglacial basin immediately upstream of the grounding line. The reverse bed slope is steep, with about 400 m of decline over 40 km. The basin floor is smooth and flat, with little small-scale topography that would delay retreat, indicating that it has been covered with marine sediment,and was previously deglaciated. Upstream of the basin, well-defined glacially carved fjords with bars at their mouths testify to the position of a former ice margin about 200 km inland from the present margin. Evidence so far suggests that the Weddell Sea sector of the West Antarctic Ice Sheet has been stable, but in the light of our data we propose that the region could be near a physical threshold of substantial change.
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关于峡湾和峡湾山谷形成的注释
DOI：
--
发表时间：
1967
期刊：
影响因子：
--
作者：
H. Holtedahl
通讯作者：
H. Holtedahl
影响因子：
5.2
作者：
Padman, Laurie;Erofeeva, Svetlana Y.;Fricker, Helen Amanda
通讯作者：
Fricker, Helen Amanda
将卫星观测与建模相结合：南极洲 Filcher-Ronne 冰流的基础剪切应力
DOI：
10.1098/rsta.2006.1799
发表时间：
2006
期刊：
Philosophical Transactions of the Royal Society A: Mathematical, Physical and Engineering Sciences
影响因子：
--
作者：
I. Joughin;J. Bamber;T. Scambos;S. Tulaczyk;M. Fahnestock;D. Macayeal
通讯作者：
D. Macayeal
影响因子：
4.9
作者：
J. Dowdeswell;J. Evans;C. Ó. Cofaigh;John B. Anderson
通讯作者：
J. Dowdeswell;J. Evans;C. Ó. Cofaigh;John B. Anderson
影响因子：
56.9
作者：
Scherer, RP;Aldahan, A;Kamb, B
通讯作者：
Kamb, B