江苏中、南部及邻区地震重新定位及在断层研究中的应用

Hypocenter relocation in central and southern Jiangsu province and adjacent areas,China and its application to fault research

本文分析了地震相对定位的双差法和地壳结构与定位联合反演方法的优势与局限性,在联合反演中用遗传算法最优化,将上述两种方法结合,对江苏省中南部和相邻地区进行地震重新精定位.先对研究区进行地壳结构与定位联合反演,然后用得到的地壳结构,用双差法进行相对定位.就该区主要断层的平面分布及与地震的关系,溧阳6.0级地震、南黄海6.2级地震、常熟—太仓5.1级地震的震源深度与发震构造,常熟-张家港间震群的震源深度进行了分析讨论.

The advantage and disadvantage of Double-Difference（DD） technique and Joint Hypocentral Determination（JHD） technique to locate earthquakes are analyzed.Combining above two methods and applying the Genetic Algorithm（GA） to optimization,we relocated the hypocenters in central and southern Jiangsu province and adjacent areas（29°~34°N,117.5°~122.5°E） in East China.Firstly,we used GA for inversion to get crustal structure of the research area,then using DD to get precise relative locations for 58% original events,and last 42% events were located by GA.The relationship between events and the faults,the correlation of focus-depth and fault of Liyang M6.0 earthquake,southern Yellow Sea M6.2 earthquake,Changshu-Taicang M5.1 earthquake are discussed,the feature of focus-depth of the Changshu-Zhangjiagang swarm is analysed.