丽江地震前后震区环境应力场时空变化

Tempospatial variation of the ambient stress field in the seismic area before and after Lijiang earthquake

构造应力场是一个应力强度随时间和空间变化的动态场，在地震孕育、发生过程中，它往往呈现出明显的时空调整变化。本文利用地震记录资料，在时间域里测算中小地震剪应力值，追踪分析丽江地震前后震区环境应力场强度时空动态变化图象，探讨其与强震孕育发生过程的关系，并对震区环境应力场时空变化与某些地震前兆的关系作了初步分析。

he tectonic stress field is a dynamic one whose strength varies with time and space.There exists an obvious adjustment variation in time and space during the process of an earthquake preparation and generation.In this paper,the shear stress values for moderate and small earthquakes are measured by means of the seismic recordings,and further the dynamic patterns of ambient stress field in the seismic area before and after Lijiang earthquake are analyzed to investigate for the relationship between seismic precursor and ambient stress field.