The evolution of the subglacial landscape of Antarctica
The evolution of the subglacial landscape of Antarctica
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DOI：
10.1016/j.epsl.2010.02.012
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发表时间：
2010-04-15
影响因子：
5.3
通讯作者：
Hulton, Nicholas R. J.
中科院分区：
文献类型：
--
作者：
Jamieson, Stewart S. R.;Sugden, David E.;Hulton, Nicholas R. J.
其目的是利用冰盖和侵蚀模型研究南极洲冰下景观的演变。我们确定了大陆冰川作用的不同阶段，并对与每个阶段相关的侵蚀过程进行了建模。该模型将侵蚀与基本的热状况联系起来，并表明南极内陆的大部分地区可能遭受了不到200米的侵蚀。侵蚀深度反映了暖基冰的存在或不存在，以及冰流方向的一致性。这些信息与有关北半球冰川地貌的知识和对初始地形的一些简单但有力的假设相联系，被用来绘制南极冰下地貌地图，其中大部分低地内部类似于劳伦斯和斯堪的纳维亚地盾典型的区域冲刷地貌。在大陆边缘附近，选择性的线性侵蚀使先前存在的河谷过度加深了多达2.8公里。毗邻这类排水系统的高海拔高原在寒冷的冰层下存活了下来，基本上没有改变。高侵蚀速率是由基冰中陡峭的温度梯度造成的。甘布尔采夫山脉、Dronning Maud陆地的高地和西南极的地块等山区可能具有当地高山冰川的特征。这样的景观可能在过去34年或更长时间里一直受到冷冰层的保护。(C)2010爱思唯尔B.V.保留所有权利。
The aim is to investigate the evolution of the subglacial landscape of Antarctica using an ice sheet and erosion model. We identify different stages of continental glaciation and model the erosion processes associated with each stage. The model links erosion to the basal thermal regime and indicates that much of the Antarctic interior may have been subject to less than 200 m of erosion. The depth of erosion reflects the presence or absence of warm-based ice and the consistency of ice flow direction. This information, linked with knowledge about landscapes of glaciation in the northern hemisphere and some simple but robust assumptions about initial topography, is used to generate a map of the subglacial Antarctic landscape in which much of the lowland interior resembles the landscapes of areal scouring typical of the Laurentian and Scandinavian shields. Near the continental margins selective linear erosion has overdeepened pre-existing river valleys by as much as 2.8 km. High elevation plateaus adjacent to such drainage systems have survived largely unmodified under cold-based ice. High erosion rates result from steep thermal gradients in basal ice. Mountain regions such as the Gamburtsev Mountains, uplands in Dronning Maud Land and massifs in West Antarctica are likely to bear features of local alpine glaciation. Such landscapes may have been protected under cold-based ice for the last 34 Myrs or possibly longer. (C) 2010 Elsevier B.V. All rights reserved.