Vulnerability of East Antarctic Ice Streams to warm Ocean Water Incursions

东南极冰流对温暖海水入侵的脆弱性

• 批准号: 1245879
• 负责人: Frank Nitsche
• 金额: $ 37.42万
• 依托单位: Columbia University
• 依托单位国家: 美国
• 项目类别: Standard Grant
• 财政年份: 2013
• 资助国家: 美国
• 起止时间: 2013-07-01 至 2017-06-30
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=1245879&HistoricalAwards=false
• 关键词: Vulnerability; East; Antarctic; Ice; Streams

Intellectual Merit: This project will determine the potential vulnerability of key ice streams to incursions of warmer ocean water onto the continental shelf and if this mechanism could already explain any of the observed thinning of the ice sheet. It will provide important constrains on ice dynamic of the investigated section of the EAIS, and thus will be critical for future ice sheet models and provide mechanisms for EAIS contributions to past sea level high-stand. The PI proposes to investigate four key ice stream systems on the continental shelf between ~90°E and 160°E. They will use multibeam bathymetry to identify if and where cross-shelf troughs exist to help determine whether these troughs could provide potential pathways for warmer ocean water. Furthermore, detailed analysis of morphological features of these troughs could provide information on past ice dynamic, maximum extent, and flow direction of related paleo ice streams. The PIs will also conduct water column measurements along these troughs and on the continental slope to determine whether warmer ocean water could enter the shelf in the near future, or if such water has already entered any troughs, and thus might be causing the observed thinning of some ice streams.Broader impacts: This project includes the participation and support of undergraduate and graduate students in field work and data analysis. The possible involvement of a PolarTREC teacher and the Earth2Class teachers program will reach out to K-12 students.

智力优势：该项目将确定主要冰流对较温暖的海水侵入大陆架的潜在脆弱性，并确定这一机制是否已经能够解释观察到的冰盖变薄的现象。它将为EAIS研究断面的冰动力学提供重要的约束条件，因此将对未来的冰盖模式至关重要，并为EAIS对过去海平面高水位的贡献提供机制。PI建议调查约90°E和160°E之间大陆架上的四个关键冰流系统。他们将使用多波束测深仪来确定跨大陆架海槽是否存在以及在何处存在，以帮助确定这些海槽是否可能为温暖的海水提供潜在的路径。此外，这些槽的形态特征的详细分析，可以提供过去的冰动态，最大范围内，和相关的古冰流的流动方向的信息。项目研究员还将沿着这些海槽和大陆坡进行水柱测量，以确定较暖的海水是否可能在不久的将来进入大陆架，或者这些海水是否已经进入任何海槽，从而可能造成所观察到的一些冰流变薄的现象。PolarTREC教师和Earth 2Class教师计划的可能参与将覆盖K-12学生。