摘要
调查了北部湾6.1、6.2级地震的烈度分布,陆地最高达六度,六度区的长轴呈NW向。研究了海底地形、重力资料、断裂产状、震中空间分布以及震源机制解,结果表明,该地震序列是在南北向的区域应力场作用下产生的共轭剪切错动,NW向的涠洲-斜阳断裂为主要发震构造,一系列较小的余震则是NE向断裂活动引发的。
We investigated the intensity distribution of the earthquakes with magnitude 6.1 and 6.2 in Beibuwan.The result shows that the maximum intensity in continent was in level 6,and the major axis of such zone was in the direction of NW.After studying on submarine morphology,gravity data,fracture occurrence,space distribution of the epicenters and the solution of focal mechanism,we found that the earthquakes were caused by the conjugate shear dislocation of the stress field in the direction of NS, the periclinal faults in the direction of NW were the main seismogenic structure,while the small aftershocks were caused by the activity of the faults in the direction of NE.