COLLABORATIVE RESEARCH: Finite Element Modeling of a Subducted Topographic High: Determining Regional Stress Changes Due to Subducting Features

合作研究：俯冲地形高压的有限元建模：确定俯冲特征引起的区域应力变化

• 批准号: 0440229
• 负责人: Carolina Lithgow-Bertelloni
• 金额: $ 3.56万
• 依托单位: Regents of the University of Michigan - Ann Arbor
• 依托单位国家: 美国
• 项目类别: Standard Grant
• 财政年份: 2005
• 资助国家: 美国
• 起止时间: 2005-01-01 至 2007-12-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=0440229&HistoricalAwards=false
• 关键词: COLLABORATIVE; RESEARCH; Finite; Element; Modeling

Proposal "Collaborative Research: Finite Element Modeling Of A Subducted Topographic High: Determining Regional Stress Changes Due To Subducing Features" EAR 0440243 and 0440229 With the majority of global seismicity occurring in subduction zones, it is very important to understand the stress conditions in the subduction environment. Variations in the details of earthquakes in these regions are likely due to variations in stress conditions between subduction zones. Key factors that can impact the stress conditions in subduction zones include mantle flow and the interaction between the overriding and subducting plates at the plate interface. The plate interface may vary in roughness depending on a variety of features on the incoming plate, such as presence of thick sediment packets, horst and graben structures, seamounts, ridges, and fracture zones. These subducting plate structures not only influence the stress state within the subduction zone, but may also control the size and rupture behavior of large subduction zone earthquakes, as suggested for large earthquakes in Costa Rica and Nankai subduction zones. This proposal focuses on examining the stress state in these two subduction zones, with goals to examine the relationship between stresses, subducted features, and seismicity patterns seen in Costa Rica and Nankai, stress triggering of large earthquakes in these regions, and determining conditions for which topographic features may act as zones of high earthquake slip or a barrier to earthquake rupture. Two and 3D modeling of the subduction zone environment will provide opportunities to explore the effects of viscoelastic relaxation and triggering, frictional properties at the trench interface, and the bathymetric variability of the subducted oceanic lithosphere on earthquake patterns. Results from this effort will be applied to knowledge of earthquake hazards in Costa Rica and Nankai, and may be extended to other subduction zones as well.

提案“合作研究：俯冲地形高压的有限元模拟：确定由于俯冲特征引起的区域应力变化“0440243和0440229由于大多数全球地震活动发生在俯冲带，了解俯冲环境中的应力条件非常重要。这些地区地震细节的变化可能是由于俯冲带之间应力条件的变化。影响俯冲带应力状态的关键因素包括地幔流动和俯冲板块与俯冲板块在板块界面的相互作用。板块交界面的粗糙度可能会有所不同，这取决于进入板块的各种特征，例如是否存在厚沉积物包、地垒和地堑结构、海山、山脊和断裂带。这些俯冲板块结构不仅影响俯冲带内的应力状态，而且还可能控制俯冲带大地震的规模和破裂行为，如哥斯达黎加和南海俯冲带的大地震。本提案的重点是研究这两个俯冲带的应力状态，目的是研究应力、俯冲特征与哥斯达黎加和南海的地震活动模式之间的关系，这些地区大地震的应力触发，以及确定地形特征可能作为高地震滑动带或地震破裂屏障的条件。俯冲带环境的二维和三维建模将提供机会，探讨粘弹性松弛和触发，沟槽界面处的摩擦特性，以及俯冲海洋岩石圈对地震模式的水深变化的影响。这项工作的结果将应用于哥斯达黎加和南海的地震灾害知识，并可能扩展到其他俯冲带。