福建顺昌ML4.9级地震序列的精确定位、震源机制及其地震构造背景分析

摘要

利用福建数字地震台网建成以来记录到的省内发生的震级最大的顺昌4.9级震群的双差精确定位、震源机制解结果,结合当地的地震构造环境、地震活动性以及现场烈度调查结果,综合分析认为:顺昌地震为双主震型的震群活动,其主震的破裂方向应为北东向,其发震机理是在北西向主压应力为主的区域构造应力场作用下发生的北东向的右旋走滑断裂.%By using the results of accurate location and the focal mechanism solution of Shunchang ML4.9 earthquake sequences recorded by Fujian digital seismic network, the paper investigated the local seismotectonic environment, seismic activity and seismic intensity. The results show that the Shunchang earthquake is a "double main earthquakes type" swarm activity;The fracture direction of main earthquake is NE direction and its occurrence mechanism is NEdirectional slip fracture with the effect of the NW directional main compressive stress.