Topographic Controls on the Generation of Elutriated Ash Clouds: II. Nature and Dynamics of Pyroclastic Density Currents

地形对淘析灰云生成的控制：II。

• 批准号: 9725361
• 负责人: Marcus Bursik
• 金额: $ 18.64万
• 依托单位: CUBRC, INC.
• 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: 1998-02-01 至 2002-08-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=9725361&HistoricalAwards=false
• 关键词: Topographic; Controls; Generation; Elutriated; Ash

9725361 Bursik Pyroclastic flows or nuees ardentes are perhaps the most destructive, yet most poorly understood of volcanic phenomena. Because of their destructiveness, they are virtually impossible to observe directly; yet they leave deposits that have proven extremely difficult to interpret. The primary objective of the proposed research is to determine in specific, well-constrained situations the link between active flow conditions in pyroclastic flows and the resulting deposits. Because we may be able to determine what is happening within the flows, the results could have important ramifications for the simulation of flows in hazards analysis, and for volcanic hazards assessment. The proposed work will procede with experimental, theoretical and fieldwork phases. The work will begin by carefully making deposits in the laboratory under well-constrained flow conditions, using special facilities designed only for the purpose of these studies. Theoretical modeling will extend the range of applicability of the experiments by generalizing the observed flow mechanics. Laboratory and theoretical results will be tested by careful sedimentological analysis of certain diagnostic portions of pyroclastic flow deposits, especially modern deposits for which there is some information on active flow conditions.

9725361 Bursik火山碎屑流或nuees ardentes可能是最具破坏性的，但最不了解的火山现象。 由于其破坏性，它们几乎不可能直接观察到;然而，它们留下的沉积物已被证明极难解释。 拟议研究的主要目标是确定在特定的，以及约束的情况下，火山碎屑流和由此产生的存款之间的联系，活跃的流动条件。 因为我们可能能够确定流动中发生了什么，结果可能对灾害分析中的流动模拟和火山灾害评估产生重要影响。 拟议的工作将进行实验，理论和实地工作阶段。 这项工作将开始，首先在实验室中，在良好约束的流动条件下，使用专为这些研究目的而设计的特殊设施，小心地进行沉积。 理论建模将通过概括观察到的流动力学来扩展实验的适用范围。 实验室和理论结果将通过对火山碎屑流沉积物的某些诊断部分进行仔细的沉积学分析来检验，特别是对有一些关于活跃流动条件的信息的现代沉积物。