利用2010~2016年阳江地区小震资料，对围绕广东阳江6.4级地震发震构造的NEE走向平冈断层的西南段及NW走向的程村断层展布的密集地震，经双差定位方法重新进行震源位置的修定，获得了1411个精定位震源资料。依据成丛地震发生在断层附近的原则，采用模拟退火算法及高斯-牛顿算法相结合的方式，较精确地获得了2个断层面的详细参数：即平冈断层西南段走向258°、倾角85°、倾向NW，与6.4级地震的震源机制解结果十分一致，断层长度约15km并穿过了其西南端海域抵达了对岸；程村断层走向331°、倾角88°、倾向NE，长度约28km，较已有结果更长、走向也朝NE向偏转了约15°。2条陡直断层近乎垂直相交于近海，在构造应力作用下均以走滑错动为主。

Based on the data of small earthquakes in the Yangjiang area from 2010 to 2016,the paper revised the dense earthquakes surrounding the Pinggang fault and the Chengcun fault during the Yangjiang M_S6.4 earthquake by double-difference method and obtained 1411 relocated focus source parameters. According to the principle that the cluster earthquake occurs near the fault,the paper obtained the parameters of the two faults by using the simulated annealing algorithm and the Gauss-Newton algorithm. The Pinggang Fault with the strike of 258°,the dip angle of 85°,the fault length of 15km and dipping to northwest,which is very consistent with the focal mechanism of the M_S6.4 earthquake,crosses the southwest end of the sea and reaches the other side. The Chengcun Fault with the strike of 331°,the dip angle of 88°,the length of 28km,dipping to northeast,is longer than the previous data and deflects to the northeast with about 20°. The two steep faults are almost perpendicular at the offshore,and are of strike-slip motion.

P315

国家自然科学基金项目（41604055）资助