Radar-derived bed roughness characterization of Institute and Moller ice streams, West Antarctica, and comparison with Siple Coast ice
Radar-derived bed roughness characterization of Institute and Moller ice streams, West Antarctica, and comparison with Siple Coast ice
复制标题
DOI：
10.1029/2007gl031483
复制
发表时间：
2007-11-08
影响因子：
5.2
通讯作者：
Siegert, Martin J.
中科院分区：
文献类型：
--
作者：
Bingham, Robert G.;Siegert, Martin J.
冰下河床条件对冰流行为和演化具有重要控制作用，可以通过雷达成像基底反射器的 FFT 分析确定冰河床粗糙度来表征。在这里，我们评估了西南极洲研究所和莫勒冰流的河床粗糙度，并将我们的发现与西普尔海岸冰流确定的河床粗糙度进行了比较。我们发现河床粗糙度的变化是在空间上组织的，并将其归因于冰下侵蚀和沉积的不同功效，较粗糙（内陆，缓慢流动）的区域主要表现出冰期前的地形，而较平滑（下游，快速流动）的区域则表明冰期后对冰下景观的显着改变。观察到的 IIS/MIS 和 Siple 冰流的河床粗糙度特征之间的相似性表明，IIS 和 MIS 大部分位于潮湿、固结不良的沉积物之下，因此可能容易受到 Siple 冰流所经历的动态不稳定类型的影响。
Subglacial bed conditions exert a significant control on ice stream behavior and evolution, and can be characterized by determining bed roughness from FFT analysis of radar-imaged basal reflectors. Here we assess bed roughness across Institute and Moller ice streams, West Antarctica, and compare our findings with bed roughness determined across the Siple Coast ice streams. We find that variations in bed roughness are spatially organized, and attribute this to the varying efficacy of subglacial erosion and deposition, with rougher (inland, slow-flowing) regions largely manifesting preglacial topography, and smoother (downstream, fast-flowing) regions evincing significant postglacial modification to the subglacial landscape. The observed similarities between bed roughness characteristics of IIS/MIS and the Siple ice streams suggest that IIS and MIS are largely underlain by wet, poorly consolidated sediments, and may therefore be vulnerable to the types of dynamical instabilities experienced by the Siple ice streams.