Histories of accumulation, thickness and WAIS Divide location from radar layers using a new inverse approach

累积、厚度和 WAIS 的历史 使用新的逆方法从雷达层中划分位置

• 批准号: 0440666
• 负责人: Edwin Waddington
• 金额: $ 24万
• 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: 2004
• 资助国家: 美国
• 起止时间: 2004-12-15 至 2009-11-30
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=0440666&HistoricalAwards=false
• 关键词: Histories; accumulation; thickness; WAIS; Divide

This award supports development of a new modeling approach that will extract information about past snow accumulation rate in both space and time in the vicinity of the future ice core near the Ross-Amundsen divide of the West Antarctic Ice Sheet (WAIS). Internal layers, detected by ice-penetrating radar, are isochrones, or former ice-sheet surfaces that have been buried by subsequent snowfall, and distorted by ice flow. Extensive ice-penetrating radar data are available over the inland portion of the WAIS. Layers have been dated back to 17,000 years before present. The radar data add the spatial dimension to the temporally resolved accumulation record from ice cores. Accumulation rates are traditionally derived from the depths of young, shallow layers, corrected for strain using a local 1-D ice-flow model. Older, deeper layers have been more affected by flow over large horizontal distances. However, it is these deeper layers that contain information on longer-term climate patterns. This project will use geophysical inverse theory and a 2.5D flow-band ice-flow forward model comprising ice-surface and layer-evolution modules, to extract robust transient accumulation patterns by assimilating multiple deeper, more-deformed layers that have previously been intractable. Histories of divide migration, geothermal flux, and surface evolution will also be produced. The grant will support the PhD research of a female graduate student who is a mentor to female socio-economically disadvantaged high-school students interested in science, through the University of Washington Women's Center. It will also provide a researchexperience for an undergraduate student, and contribute to a freshman seminar on Scientific Research.

该奖项支持开发一种新的建模方法，该方法将在西南极冰盖（WAIS）的罗斯-阿蒙森分水岭附近的未来冰芯附近提取有关空间和时间上过去雪积累速率的信息。由冰穿透雷达探测到的内部层是等时线，或被随后的降雪掩埋的前冰盖表面，并被冰流扭曲。 广泛的冰穿透雷达数据可在内陆部分的WAIS。地层可以追溯到距今17,000年前。 雷达数据为冰芯的时间分辨积累记录增加了空间维度。积累率传统上来自年轻的，浅层的深度，使用当地的1-D冰流模型的应变校正。较老、较深的地层更容易受到大的水平距离上的流动的影响。然而，正是这些更深的层次包含了关于长期气候模式的信息。 该项目将使用地球物理反演理论和2.5D流带冰流正演模型，包括冰表面和层演化模块，通过同化多个更深、更变形的层来提取强大的瞬态积累模式，这些层以前是难以处理的。 还将产生分水岭迁移、地热通量和地表演变的历史。 该赠款将通过华盛顿大学妇女中心，支持一名女研究生的博士研究，她是对科学感兴趣的社会经济处境不利的女高中生的导师。它还将为本科生提供研究经验，并为科学研究的新生研讨会做出贡献。

项目成果

Holocene accumulation and ice flow near the West Antarctic Ice Sheet Divide ice core site

• DOI: 10.1002/2015jf003668
• 发表时间: 2016-05
• 期刊: Journal of Geophysical Research: Earth Surface
• 作者: M. Koutnik;T. Fudge;H. Conway;E. Waddington;T. Neumann;K. Cuffey;C. Buizert;K. Taylor

Recent thinning and migration of the Western Divide, central West Antarctica

• DOI: 10.1029/2009gl038072
• 发表时间: 2009-06
• 期刊: Geophysical Research Letters
• 影响因子: 5.2
• 作者: H. Conway;L. A. Rasmussen

Weak bed control of the eastern shear margin of Thwaites Glacier, West Antarctica

• DOI: 10.3189/2013jog13j050
• 发表时间: 2013-10
• 期刊: Journal of Glaciology
• 影响因子: 3.4
• 作者: J. MacGregor;G. Catania;H. Conway;D. Schroeder;I. Joughin;D. Young;S. Kempf;D. Blankenship