Basal Conditions of Ice Stream D and Related Borehole Studies of Antarctic Ice Stream Mechanics

该奖项旨在支持一个为期四年的项目，该项目将使用先前应用于冰流B的技术来研究冰流D的基本条件，目的是确定在这个大冰流底部通过钻孔地球物理观察到的物理条件和过程是否与在冰流B中观察到的一致，并指出冰流的共同基本机制。本项目包括冰流D的两个部分的比较，上游段流速适中（约80米/年），下游段流速较高（约400米/年）。这种比较将有助于揭示哪些物理变量或变量组合主要负责流。钻孔观测监测的变量包括基础水压、基础滑动速度、冰下碛物的流动特性和沉积学特征，冰温剖面包括基础输水速度、与基础水系的连接时间、基础融化速率等。

This award is for support for a four year program to study the basal conditions of ice stream D using techniques previously applied to ice stream B. The objective is to determine whether the physical conditions and processes to be observed by borehole geophysics at the base of this large ice stream are consistent with what has been observed at ice stream B and to point to a common basal mechanism of ice streaming. This project includes a comparison between two parts of ice stream D, an upstream reach where flow velocities are modest (about 80 meters/year) and a downstream reach of high velocity (about 400 meters/year). The comparison will help to reveal what physical variable or combination of variables is mainly responsible for the streaming flow. The variables to be monitmred by borehole observation include basal water pressure, basal sliding velocity, flow properties and sedimentological characteristics of subglacial till if present, ice temperature profile including basal water transport velocity, connection time to the basal water system, basal melting rate and others.