Onset of fast ice flow in Recovery Ice Stream, East Antarctica: a comparison of potential causes
Onset of fast ice flow in Recovery Ice Stream, East Antarctica: a comparison of potential causes
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DOI：
10.3189/2014jog14j067
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发表时间：
2014-01-01
影响因子：
3.4
通讯作者：
Scambos, T.
中科院分区：
文献类型：
--
作者：
Langley, K.;Tinto, K.;Scambos, T.
恢复冰流有多个分支，深入东南极冰盖。我们使用新的空中和地面为基础的地球物理学给上集水区的第一个全面的概述，并通过限制的物理环境，以推进我们的理解的控制机制的快速流动的开始。400公里宽的冰流延伸到冰下湖的恢复，一个地区的特点是地壳边界，床粗糙度的变化，基岩地形台阶和四个地形盆地（A-D），其中三个（A-C）含有冰下水。所有这些特征都被认为是导致快速血流发作的潜在因果机制。在B湖和C湖，冰下水位于下游山脊陡峭的盆地中，与A湖下游边缘的缓坡山脊形成对比。冰流中流速最快的分支来自A湖。沿沿着四个恢复湖的多个因果机制的存在，使我们能够确定基础水作为一个主导因素的快速流动的开始，但只有当它被存储在一个浅边的盆地，它可以润滑下游的流量。相对较小的地形障碍似乎抑制流。
Recovery Ice Stream has multiple branches reaching far into the East Antarctic ice sheet. We use new airborne and ground-based geophysics to give the first comprehensive overview of the upper catchment and, by constraining the physical setting, to advance our understanding of the controlling mechanisms for the onset of fast flow. The 400 km wide ice stream extends towards the Recovery Subglacial Lakes, a region characterized by a crustal boundary, a change in bed roughness, a bedrock topographic step and four topographic basins (A-D), three of which (A-C) contain subglacial water. All these characteristics are considered potential causal mechanisms that contribute to the onset of fast flow. In Lakes B and C the subglacial water is located in basins with sharp downstream ridges, in contrast to the gently sloping ridge on the downstream margin of Lake A. The fastest-flowing branch of the ice stream emanates from Lake A. The presence of multiple causal mechanisms along the four Recovery Lakes allows us to identify basal water as a dominant factor for the onset of fast flow, but only if it is stored in a shallow-sided basin where it can lubricate the flow downstream. Relatively minor topographic barriers appear to inhibit streaming.