Rheology of Basal Ice

基础冰的流变学

• 批准号: 9713383
• 负责人: Roger Hooke
• 金额: $ 4.31万
• 依托单位: University of Minnesota-Twin Cities
• 依托单位国家: 美国
• 项目类别: Standard Grant
• 财政年份: 1998
• 资助国家: 美国
• 起止时间: 1998-03-15 至 2000-02-29
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=9713383&HistoricalAwards=false
• 关键词: Rheology; Basal; Ice

This work is to study glacier dynamics and hydrology of a glacier in Sweden. The glacier drainage system, the subglacial till and its velocity close to the bottom, will be examined. The data obtained will be used, in conjunction with a finite element model of the flow, to study the rheology of this glacier. An instrument panel beneath the glacier Engabreen in Norway has been installed, which contains a conical bump, 0.15 m high. The bed of the glacier is accessed through tunnels in the rock, excavated for hydroelectric purposes. The ice is about 200 m thick at the site of the panel. The measurements made include the temperature distribution in the bump, the pressure on either side of the bump, the total bed-parallel force, and the sliding speed. The sliding speed is measured by monitoring the movement of ice past windows with the use of video cameras. The investigators plan to melt out the layer of dirty ice at the base of the glacier and thereby bring clean ice in contact with the instrumented panel. Thus, markers emplaced in the ice above the bed will be visible by the video cameras, and the ice velocity distribution will be determined. In addition, the PIs will measure the water content of the basal clean ice, and take cores for fabric analysis.

这项工作是研究冰川动力学和水文的冰川在瑞典。 冰川排水系统，冰下冰碛物及其接近底部的速度，将被检查。所获得的数据将被用来，结合流动的有限元模型，研究这个冰川的流变学。 在挪威恩格森冰川下安装了一个仪表板，其中包含一个0.15米高的圆锥形凸起。 冰川床是通过岩石中的隧道进入的，这些隧道是为了水力发电而挖掘的。 在嵌板所在地，冰厚约200米。 所做的测量包括凸块中的温度分布、凸块两侧的压力、总的床平行力和滑动速度。 滑动速度是通过使用摄像机监测冰经过窗户的运动来测量的。研究人员计划融化冰川底部的脏冰层，从而使干净的冰与仪表板接触。 这样，摄像机就可以看到冰床上方的冰中所放置的标记，并确定冰的速度分布。 此外，PI将测量基础清洁冰的含水量，并采取核心进行结构分析。