Glacio-isostasy and Glacial Ice Load at Law Dome, Wilkes Land, East Antarctica
Glacio-isostasy and Glacial Ice Load at Law Dome, Wilkes Land, East Antarctica
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东南极洲威尔克斯地 Law Dome 的冰川均衡和冰川冰负荷
DOI：
10.1006/qres.1999.2125
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发表时间：
2000
影响因子：
2.3
通讯作者：
C. Zweck
中科院分区：
文献类型：
--
作者：
I. Goodwin;C. Zweck
东南极洲威尔克斯地全新世海平面最高点或“海限”在少数几个分散的地点达到了现在海平面以上1030 m。最详细的海洋界限数据记录在风车群岛和巴德海岸的边缘法律圆顶冰帽，圆顶的东南极冰盖（EAIS）。自6900年以来，相对海平面下降了30米，风车群岛也随之出现。地球流变学的数值模拟用于确定观测到的相对海平面下降的冰川均衡分量。冰川学证据表明，大多数EAIS增厚发生在其边缘，并扩展到大陆架。因此，一个区域冰史的末次盛冰期（LGM）的冰川均衡模拟，以测试是否观察到的相对海平面下降主要是由区域冰盖的变化。模拟的结果表明，冰后期（13,000至8000年14 C B.P）去除770和1000米之间的冰负荷从周围的法律圆顶和相邻的EAIS的边缘产生了观察到的相对海平面降低。这样一个额外的冰负荷将与40至65公里的法律圆顶扩展到附近的大陆架断裂，以及几百米的冰增厚的邻接沿海斜坡的EAIS高达2000米的海拔。而观察到的相对海平面的变化被证明是强烈的区域冰盖变化的影响，在风车群岛的冰川均衡响应的结果，从区域的组合，并在较小程度上，舌形范围内的影响。在Law Dome边缘解释的全新世相对海平面下降与沿着Wilkes Land和Oates Land海岸（105°-160° E）的其余部分解释的下降之间的对应关系表明，沿着Wilkes Land和Oates Land之间的EAIS边缘存在高达1000 m的类似冰负荷。
Abstract The Holocene sea-level high stand or “marine limit” in Wilkes Land, East Antarctica, reached ∼30 m above present sea level at a few dispersed sites. The most detailed marine limit data have been recorded for the Windmill Islands and Budd Coast at the margin of the Law Dome ice cap, a dome of the East Antarctic Ice Sheet (EAIS). Relative sea-level lowering of 30 m and the associated emergence of the Windmill Islands have occurred since 6900 14C (corr.) yr B.P. Numerical modeling of the Earth's rheology is used to determine the glacio-isostatic component of the observed relative sea-level lowering. Glaciological evidence suggests that most of EAIS thickening occurred around its margin, with expansion onto the continental shelf. Consequently, a regional ice history for the last glacial maximum (LGM) was applied in the glacio-isostatic modeling to test whether the observed relative sea-level lowering was primarily produced by regional ice-sheet changes. The results of the modeling indicate that the postglacial (13,000 to 8000 14C yr B.P) removal of an ice load of between 770 and 1000 m from around the margin of the Law Dome and adjacent EAIS have produced the observed relative sea-level lowering. Such an additional ice load would have been associated with a 40- to 65-km expansion of the Law Dome to near the continental shelf break, together with a few hundred meters of ice thickening on the adjoining coastal slope of the EAIS up to 2000 m elevation. Whereas the observed changes in relative sea level are shown to be strongly influenced by regional ice sheet changes, the glacio-isostatic response at the Windmill Islands results from a combination of regional and to a lesser extent, Antarctic-wide effects. The correspondence between the Holocene relative sea-level lowering interpreted at the margin of the Law Dome and the lowering interpreted along the remainder of the Wilkes Land and Oates Land coasts (105°–160° E) suggests that a similar ice load of up to 1000 m existed along the EAIS margin between Wilkes Land and Oates Land.