山东长岛海域震群重定位及震源特征研究

Research on the Repositioning and Seismic Source Characters of the Changdao Coastal Earthquake Sequences, Shandong Province

基于山东数字化地震台站的震相资料和胶东半岛地区的速度结构模型,利用双差定位方法对2017年2月14日开始的山东长岛地区双震群进行重新定位,结果显示主震群余震序列分布沿一级断裂分布,震群位置比较集中。并利用CAP方法(Cut and Paste)对长岛海域2个震群中的几个较大地震进行震源机制解的反演分析,其中,2017年3月3日的主震震源机制解的节面I走向为320°,倾角57°,滑动角为12°;节面Ⅱ走向为223.4°,倾角80°,滑动角为146.4°;主震的最佳拟合深度在9.7km,6次较大地震的节面I走向也基本一致。

Based on the data collected by the Shandong Digital seismic Network and the speed-structure model,we use the accurate double-difference location method to relocate two sequences starting from the February 14,2017,the result show that the distribution of the aftershocks of the main sequence is along the class-I fault in earthquake swarm,In this paper also applied the CAP method to analyze inversely the focal mechanism solutions of several earthquake in the Changdao costal area.The focal mechanism solution of the main earthquake on March 3,2017 includes the flowing parameters:nodal plane I(trend of 320°,dip angle 57°and slide angle 12°);plane II(trend of223.4°,dip angle 80°and slide angle 146.4),The optimum fitting depth is 9.7 km The solutions of nodal plane of these six large earthquakes agree with each other well.