摘要
针对川滇地区 ,在大量搜集、总结前人资料和结果的基础上 ,建立了包括上地壳、下地壳 (两层 )、上地幔等 4层结构的三维有限元模型 .通过反复调试 ,确定了其边界条件 ,并且计算了川滇地区背景应力场、断层蠕动产生的应力场和强震触发的应力场 ,以及它们的动态变化 .结果表明 :后续地震大多发生在前面地震引发的库仑破裂应力正值区 ,前一地震对后续地震有一定的触发作用 ,强震是在较高的应力背景下成组发生的 .这对判断、识别地震异常 ,提高地震预测水平有着很大的意义 .
Based on the latest achievement about activities of geological structure, a 3-D finite-element model containing four layers of upper crust, lower crust (two layers) and upper mantle is established in the paper. By repeated tests and revisions, the boundary conditions of the model are determined. And then the background stress field, the stress field caused by fault creep and the stress field triggered by strong earthquake in Sichuan-Yunnan region, as well as their dynamic variations are calculated. The results indicate that the latter earthquake often occurs in the area with positive Coulomb rupture stress changeassociated with the former one, the former earthquake has a triggering effect on the latter one to a certain extent, and strong earthquake often occur in groups under the background of high stress, which is of great significance for distinguishing seismic anomalies, as well as for improving the level of earthquake prediction.
出处
《地震学报》
CSCD
北大核心
2004年第6期567-575,共9页
Acta Seismologica Sinica
基金
国家重点基础研究发展规划项目 (G19980 4 0 70 2 )
国家"十五"科技攻关项目<基于断层相互作用理论的地震孕育发生过程和短期前兆模型研究>(2 0 0 1BA6 0 1B0 2 0 1 0 3)共同资助
关键词
三维有限元模型
背景应力场
断层蠕动应力场
强震触发应力场
D finite element model
background stress field
stress field caused by fault creep
stress field triggered by strong earthquake
