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

0086297 Anandakrishnan该奖项支持一个为期四年的项目，以更好地了解罗斯海海湾（A-F）的冰流，通过快速移动大量的冰到罗斯冰架的崩解前沿，这些冰流排出了南极西部冰盖（WAIS）的内部。 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，控制它们当前的接地线、边缘和头部位置的因素，对于任何试图模拟WAIS系统和预测冰盖未来的尝试都是至关重要的。 对于南极西普尔海岸的冰流，从无滑动（或全部内部变形）到以滑动为主的运动的过渡被定义为“起始区”。 为了充分理解（并充分建模）WAIS，必须更好地理解这个发病区域。 冰流的侧缘也是一个需要更好解释的过渡。 关于其位置的控制假说从“纯冰川学”到“纯地质学”都有。 因此，为了精确地模拟冰盖，需要基底边界条件（粗糙度、湿度、冰碛物特性）和良好的冰下地质图，显示沉积盆地的分布、厚度和特性。 这些参数可以通过地震、雷达和其他地球物理方法来估计。 冰流D的过渡区将通过该耦合地球物理实验进行详细研究。 此外，还将在冰流C和D上选择其他位置，以与冰流D上的主要位置进行比较和对比。 主要营地的选址将基于现有的雷达、GPS和卫星数据以及建模社区的输入。

0086297AnandakrishnanThis 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.