海南岛及邻区地震精确定位及断裂构造分析*
徐晓枫,王惠琳,陈小敏

(海南省地震局,海南 海口 570203)

双差定位法; 海南岛及邻区; 震源深度; 地震构造; 地震活动

Analysis on Accurate Location of Earthquakes and Fault Structure in Hainan Island and its Adjacent Areas
XU Xiao-feng,WANG Hui-lin,CHEN Xiao-min

(Earthquake Administration of Hainan Province,Haikou 570203,Hainan,China)

double difference location method; Hainan island and its adjacent areas; focal depth; seismic structure; seismic activity

备注

利用双差地震定位法对2000～2012年海南岛及邻区ML≥1.0的1 035次地震进行重新定位,得到了820次地震的重定位结果。结果 显示:重新定位后的结果大大改善了原地震定位的精度,且部分震群更加集中密集,并向断裂带趋近; 震源深度分布更为合理,精定位前震源深度绝大多数位于10 km处,而精定位后发散分布于地下20 km内,近似呈正态分布形态,优势分布深度为5～15 km; 重定位后的地震呈现垂直条带分布特征,体现了断裂带的运动构造,更加符合断裂带的地震活动特点。

Using the double difference location method,the 1 035 ML≥1.0 earthquakes from 2000 to 2012 was relocated,and the relocation results of 820 earthquakes was obtained in Hainan Island and its adjacent area. The results showed that the location accuracy of the original earthquake had improved,and the epicenters of part of earthquake swarm distributed in cluster zone,which were approaching to the fault zone after relocation. The distribution of the focal depth was more reasonable. Before the accurate-positioning,the focal depths mainly distributed at 10 km. However,the focal depths divergently distributed within underground 20 km which was similar to normal distribution,and the advantage distribution depth is 5～15 km after the accurate-positioning. The distribution characteristic of the relocated earthquakes showed the characteristic of vertical belt,which reflected the tectonic movement of the fault and was close to seismic activity characteristic of the fault.