MRI: Development of a Thermal Melt Probe System for Extensive, Low-Cost Instrument Deployment at the Bed of the Greenland Ice Sheet

MRI：开发热熔探头系统，用于在格陵兰冰盖底部广泛、低成本地部署仪器

• 批准号: 1228477
• 负责人: Dale Winebrenner
• 金额: $ 65.93万
• 依托单位: University of Washington
• 依托单位国家: 美国
• 项目类别: Standard Grant
• 财政年份: 2012
• 资助国家: 美国
• 起止时间: 2012-08-01 至 2015-07-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=1228477&HistoricalAwards=false
• 关键词: MRI; Development; Thermal; Melt; Probe

The aim of this MRI proposal is to develop a low-cost instrumentation package for studying the hydrologic system at the bases of glaciers and ice sheets. Estimating future contributions of the Greenland Ice Sheet (GIS) to sea level rise depends critically on a quantitative understanding of dynamic subglacial hydrology. Pressurized water in subglacial hydrological networks strongly modulates sliding of the ice sheet over its bed, even as those networks evolve in response to input rates and quantities of surface melt water, on a wide range of scales in time and space. The pressure of water beneath the ice sheet is thus the single most important dynamic and diagnostic variable in the system. Despite this importance there are presently very few field measurements of pressure (or any other subglacial variable) beneath ice sheets, because of the practical limitations of existing methods. Existing ice drilling and coring rigs capable of reaching those depths comprise tons of equipment and fuel, and are operated by crews of several or more people. Without dramatically increasing their logistics loads, many projects are therefore unable to acquire measurements of basal water pressure, despite direct relevance of such data to their investigations. The investigators propose to develop thermal melt probes, that would melt their way autonomously down through the ice at speeds of meters per hour. Advances in miniaturized instrumentation, solid-state power-control electronics, and high-voltage cabling now enable reliable, robust and sophisticated measurements of basal water pressure and other variables with small, logistically light melt probes. The proposal is based on a subscale prototype that has been built and tested in sea ice and a mountain glacier. The investigators plan to commission the new system by emplacing at least one probe beneath 600-1000 m of ice in western Greenland and acquiring basal water pressure data to serve as a proof-of-concept for a wide range of further proposals. Undergraduate and graduate students will be trained in the course of this project.

该MRI建议的目的是开发一个低成本仪器包，用于研究冰川和冰盖基础的水文系统。估计格陵兰冰盖（GIS）对海平面上升的未来贡献取决于对动态亚冰川水文学的定量理解。冰川水文网络中的加压水强烈调节冰盖在床上的滑动，即使这些网络响应于输入速率和表面熔体水的数量而发展，在时间和空间的广泛尺度上。因此，冰盖下的水压力是系统中最重要的动态和诊断变量。尽管这一点很重要，但由于现有方法的实际限制，目前很少有压力（或任何其他亚冰川变量）的现场测量。现有的冰钻和加油钻机能够到达这些深度包括大量的设备和燃料，并且由几个或更多人的机组人员操作。因此，尽管这些数据与研究直接相关，但在没有大幅增加其物流负载的情况下，许多项目仍无法获得基础水压的测量。研究人员建议开发热熔体探针，以每小时米的速度自动地通过冰融化。现在，微型仪表，固态功率控制电子设备和高压电缆的进步现在可以实现基础水压和其他带有逻辑上轻熔体探针的基础水压和其他变量的可靠，健壮和复杂的测量。该提案是基于在海冰和山地冰川建造和测试的子量表原型的基础上。调查人员计划通过将至少一个探针在西部格陵兰西部的600-1000 m以下进行探测，并获取基础水压数据，以作为广泛的进一步建议的概念验证。本科生和研究生将在该项目的过程中接受培训。