Investigation of complex rupture processes in the 2008 M8 Wenchuan earthquake using dynamic source models

利用动力震源模型研究2008年汶川8级地震的复杂破裂过程

• 批准号: 1015597
• 负责人: Benchun Duan
• 金额: $ 12.6万
• 依托单位: Texas A&M Research Foundation
• 依托单位国家: 美国
• 项目类别: Continuing Grant
• 财政年份: 2010
• 资助国家: 美国
• 起止时间: 2010-10-01 至 2013-09-30
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=1015597&HistoricalAwards=false
• 关键词: Investigation; complex; rupture; processes; 2008

This project is to use dynamic source models to investigate complex rupture processes in the 2008 Ms 8.0 Wenchuan (China) earthquake and to advance our understanding of what controls spontaneous rupture propagation on complex fault systems embedded in complex geologic structure in large earthquakes. The primary goals of the proposed research are (1) to understand how and why the rupture in the Wenchuan earthquake spontaneously propagated (and terminated) on the geometrically complex Longmenshan fault system, and (2) to advance our general understanding of how large earthquakes work, by investigating complex rupture processes in the event using spontaneous rupture models constrained by surface rupture, geological and geophysical observations of fault geometry and velocity structure, laboratory-derived friction laws, and near-field strong ground motion recordings. Simultaneous rupturing of a branched fault system formed by the Beichuan fault and the Pengguan fault and incomplete coseismic slip partitioning between the two faults observed in this earthquake are two major scientific questions to be explored.This project is part of a longer-term research program that will develop complete earthquake cycle models and use these models to assimilate a variety of observations of earthquake processes, to test existing theories and formulate new theories. The PI will also use a hybrid MPI/OpenMP approach to parallelize an existing 3D finite element dynamic rupture code (EQdyna) in this project so that the above questions can be explored at high resolutions using high-performance supercomputing systems, which is necessary to accurately capture rupture propagation on geometrically complex faults and inelastic off-fault deformation in the models.

该项目旨在使用动态震源模型来研究 2008 年中国汶川 8.0 级地震中的复杂破裂过程，并加深我们对大地震中复杂地质结构中嵌入的复杂断层系统自发破裂传播的控制因素的理解。本研究的主要目标是（1）了解汶川地震中的破裂如何以及为何在几何复杂的龙门山断层系统上自发传播（并终止），以及（2）增进我们对大地震如何发生的一般理解，通过使用受表面破裂约束的自发破裂模型、断层几何形状和速度结构的地质和地球物理观察、实验室导出的摩擦定律以及近场强地面运动记录来研究事件中的复杂破裂过程。此次地震观测到的北川断层和彭关断层形成的分支断层系统的同时破裂以及两个断层之间不完全的同震滑移分割是有待探索的两个重大科学问题。该项目是一个长期研究计划的一部分将开发完整的地震周期模型，并利用这些模型来吸收各种地震过程的观测结果，检验现有理论并制定新理论。 PI 还将在该项目中使用混合 MPI/OpenMP 方法并行化现有的 3D 有限元动态断裂代码 (EQdyna)，以便可以使用高性能超级计算系统以高分辨率探索上述问题，这对于准确地解决问题是必要的。在模型中捕获几何复杂断层上的破裂传播和非弹性断层变形。