Collaborative Research: Characterizing the Onset of Ice Stream Flow: A Ground Geophysical Field Program

9814774Alley 该奖项支持一个为期四年的项目，旨在更好地了解罗斯海海湾 (A--F) 的冰流，罗斯海海湾通过将大量冰快速移动到罗斯冰架的崩解前部来排干南极洲西部冰盖 (WAIS) 内部的水。 该项目将研究这些冰流作为内部冰和浮动冰架之间的缓冲区的作用。 它们快速流动的原因、控制其当前接地线、边缘和头部位置的因素对于任何对 WAIS 系统进行建模和预测冰盖未来的尝试都至关重要。 对于西普莱海岸的南极冰流，从无滑动（或所有内部变形）到以滑动为主的运动的过渡被定义为“起始区域”。 为了充分理解（并充分建模）WAIS，必须更好地理解这个起始区域。 冰流的侧向边缘也是一个需要更好解释的过渡。 关于控制起始区域位置的假设范围从“纯冰川学”到“纯地质学”。因此，为了准确地模拟冰盖，需要基础边界条件（粗糙度、湿度、耕作特性）和良好的冰下地质图，显示沉积盆地的分布、厚度和性质。这些参数可以通过地震、雷达和其他地球物理方法估计。冰流 D 的过渡区域将在此外，还将在冰流 C 和 D 上选定其他位置，以与冰流 D 上的主要地点进行比较和对比。主营地的选址将基于现有雷达、GPS 和卫星数据以及建模界的输入。

9814774AlleyThis award supports a four year project to develop of better understanding the ice streams of the Ross Sea Embayment (A--F) which drain the interior West Antarctic Ice Sheet (WAIS) by rapidly moving vast quantities of ice to the calving front of the Ross Ice Shelf. The project will examine the role of these ice streams as buffers between the interior ice and the floating ice shelves. The reasons for their fast flow, the factors controlling their current grounding-line-, margin-, and head-positions are crucial to any attempt at modeling the WAIS system and predicting the future of the ice sheet. For the Antarctic ice streams of the Siple Coast, the transition from no-sliding (or all internal deformation) to motion dominated by sliding is defined as the "onset-region". To fully understand (and adequately model) the WAIS, this onset region must be better understood. The lateral margins of the ice streams are also a transition that need better explanation. Hypotheses on controls of the location of the onset region range from the "purely-glaciologic" to the "purely-geologic. Thus, to model the ice sheet accurately, the basal boundary conditions (roughness, wetness, till properties) and a good subglacial geologic map, showing the distribution, thickness, and properties of the sedimentary basins, are required. These parameters can be estimated from seismic, radar, and other geophysical methods. The transition region of ice stream D will be studied in detail with this coupled geophysical experiment. In addition, selected other locations on ice streams C & D will be made, to compare and contrast conditions with the main site on ice stream D. Site-selection for the main camp will be based on existing radar, GPS, and satellite data as well as input from the modeling community.