Collaborative Research: Cosmogenic nuclide chronology and paleohydraulic modeling of late Pleistocene Missoula floods

合作研究：宇宙成因核素年代学和晚更新世米苏拉洪水的古水力模型

• 批准号: 1530097
• 负责人: Peter Clark
• 金额: $ 2.52万
• 依托单位: Oregon State University
• 依托单位国家: 美国
• 项目类别: Standard Grant
• 财政年份: 2015
• 资助国家: 美国
• 起止时间: 2015-08-01 至 2017-07-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=1530097&HistoricalAwards=false
• 关键词: Collaborative; Research; Cosmogenic; nuclide; chronology

A non-technical description of the project, which explains the project's significance and importanceThe Channeled Scablands of Washington and Oregon are spectacular landmarks of geology. They were formed at the end of the last ice age when Glacial Lake Missoula breached its dam and a catastrophic flood carved the landscape as the water made its way to the Columbia River. Recent investigations have shown there was more than one flood episode; this project will use new dating techniques to provide a closer constraint on the ages and number of flood events. The project will then use these results in conjunction with a hydraulic model to evaluate the size and duration of these flood events and the effects on the landscape. The results could be used to examine the impact of large floods on topography in other parts of the world. The project will support the education of a female PhD student from an underrepresented group.A technical description of the projectBy establishing the age of landscape development in this region, the new sampling sites strategically located to address a number of specific questions related to flood history that can be assessed with the proposed modeling scenarios, including: (1) How much of the landscape is the product of waning stages of one large flood versus of multiple-age floods? (2) How does the timing of advance and retreat the ice relate to ages of flood events? (3) Are all present flood landscapes related to the draining of glacial Lake Missoula? This new geochronology will indicate a variety of different flow paths taken by different-aged late Pleistocene mega-floods, different inundation levels for various flow events, and possibly even different source regions for generating the flows. To evaluate the implications of these anticipated results, a model will calculate time-varying topography resulting from glacial isostatic adjustment from the adjacent ice sheet, and then use a hydraulic model which solves the full two-dimensional, depth-averaged momentum and continuity equations for free-surface flow.

该项目的非技术描述解释了该项目的意义和重要的华盛顿和俄勒冈州的散布，这是地质学的壮观地标。它们是在最后一个冰河时代结束时形成的，当时冰川湖米苏拉湖违反了大坝，灾难性的洪水在水到达哥伦比亚河时雕刻了景观。最近的调查表明，有不止一个洪水事件。该项目将使用新的约会技术来对洪水事件的年龄和数量进行更紧密的限制。然后，该项目将与液压模型结合使用这些结果来评估这些洪水事件的大小和持续时间以及对景观的影响。结果可用于检查世界其他地区大洪水对地形的影响。该项目将支持一名代表性不足的小组对女性博士学位学生的教育。对建立该地区景观发展时代发展的项目描述，新的抽样站点在战略上位于战略上，可以解决与洪水历史相关的许多特定问题，可以通过建议的建模场景来评估，包括：（1）多个洪水泛滥的范围，包括：（1）众多范围的洪水范围，是一台大型洪水范围的范围，是？ （2）进步和撤退的时间与洪水事件的年龄有关？ （3）目前的洪水景观是否与冰川湖米苏拉湖的排水有关？这种新的年代学将表明由不同年龄的晚更新世大型洪水所采取的各种不同的流动路径，各种流动事件的不同淹没水平，甚至可能产生流量的不同来源区域。为了评估这些预期结果的含义，一个模型将计算出与相邻冰盖的冰川等静态调整所产生的时变地形，然后使用液压模型，该模型解决了完整的二维，深度平衡动量和连续性方程，并取得了平面表面的流动。