时间域内有限地震断层的反演问题  

THE INVERSE PROBLEM OF FINITE FAULT STUDY IN TIME DOMAIN

作　　者：姚振兴[1] 纪晨[1] 

机构地区：[1]中国科学院地球物理研究所,北京100101

出　　处：《地球物理学报》1997年第5期691-701,共11页Chinese Journal of Geophysics

基　　金：国家自然科学基金"九五"重点

摘　　要：为了解决有限地震断层破裂过程研究中的正演和反演问题，本文提出：（1）用广义反射、透射系数矩阵和广义射线理论计算上地幔及远场范围体波理论地震图的混合方法．同时采用格林函数的一种新的组合方式，可节约1／3计算机内存．（2）采用基于模拟退火的热浴算法进行全局搜索反演，不仅提高了在计算过程中新模型被接收的可能性，而且使得在时间域内目标函数的计算速度提高了近二个数量级．对1994年台湾海峡地震震源破裂过程的研究结果表明，这次地震的破裂过程相对比较简单．在前4．0s内地震断层的破裂相当剧烈，错动距离的平均值随着破裂时间增加而迅速减少．开始时破裂速度较高，前4．0s的平均值为3．1km／s，之后逐渐降至2．2km／s．错动方向随破裂的变化不大．For the forward and inverse problems in the study of earthquake rupture process by finite fault method, tWo algorithms are suggested. First, a new hybrid method,which combined of reflective and transmission coefficient matrix method and Generalized ray theory, is presented to calculate upper mantle and teleseismic body-wave synthetic seismogram. Besides so, A new combination of Green function is also suggested that can save one-third computer memory. Second, the heat-bath algorithm is used to solve this inverse problem. It can not only increase the acceptance probability in lower annealing temperature, but also great enhance the computer speed of the bine-domain objective function for nearly 100 bines. The rupture process of 1994 Taiwan strait earthquake was studied. The results show that the rupture process of this event is relative simple. During the first 4.0s, the fault rupture is qinte acute and then the average slip amplitude is fast decreased as the increasing of rupture bine. There is an initial fast rupture with average velocity of 3.1km / s during the first 4.0s, then it gradually reduces to 2.2 km/s. Relatively, the variation of rupture direction is small.

关 键 词：地震地质 断层 震源 台湾海峡 地震 

分 类 号：P315.2[天文地球—地震学]