【摘要】 2008年5月12日汶川MS8.0地震发生在龙门山断裂带.本文基于龙门山断裂带的地质与地球物理研究结果,以及高精度的地形数据、大地热流测量数据,建立了以龙门山断裂带为主要研究对象的有限元模型;以GPS观测数据、构造应力场和震源破裂过程研究结果为约束,研究了此次强烈地震的动力学背景.模拟实验结果显示:在考虑青藏高原物质向东挤压流动的同时,青藏高原与四川盆地的地形差异和流变强度差异、断层摩擦强度差异和断层产状形式均对地震起始破裂的发生位置和断层错动形式有着重要影响.本文利用地球动力学的有限元软件模拟了汶川地震地表破裂在龙门山断裂带上传播的过程.更多还原

【Abstract】 The Wenchuan MS8.0 earthquake occurred on Longmenshan faults on May 12,2008.This paper is based on previous geology and geophysics research results,high resolution elevation data,and heat flow data.We have built a finite model to study the Longmenshan faults.By using GPS data,stress field and source rupture process as constraint condition,we have studied the geodynamic background of this strong earthquake to confirm whether or not the starting rupture position of the earthquake and the fault dislocation pattern were influenced by the elevation and rheological strength difference between the Sichuan basin and Tibetan plateau,and by the different frictions of Longmenshan faults and fault geometry.The result of our computing model shows that,when considering the deep material of Tibetan plateau flowing toward east,the above factors all actually influence the starting rupture position of the earthquake and the fault dislocation pattern.This paper uses the geodynamic finite element software to simulate the rupture process of Longmenshan faults during the Wenchuan earthquake.更多还原