山西地区震源机制一致性参数时空特征分析  

Spatial-temporal Characteristics of the Consistency Parameter of Focal Mechanisms in Shanxi Area

作　　者：李丽[1,2] 宋美琴[1,2] 刘素珍[1,2] 扈桂让[1,2] 

机构地区：[1]山西省地震局,山西太原030021 [2]太原大陆裂谷动力学国家野外科学观测研究站,山西太原030021

出　　处：《地震》2015年第2期43-50,共8页Earthquake

基　　金：中国地震局星火计划(XH14010Y;XH13004);震情跟踪青年课题(2013020117);地震行业科研专项(201208009-14)

摘　　要：利用山西数字地震台网记录到的中小地震波形资料,采用层状介质中点源位错模型的广义透射系数的快速算法和理论地震图拟合直达波最大振幅比来求取小震震源机制解的方法,计算了2001年—2012年山西地区281个中小地震震源机制解,根据优势分布得到山西地区现今平均构造应力场分布,计算震源机制解应力主轴与相应的区域构造应力场主轴之间的震源机制一致性参数,分析一致性参数时空分布与中等地震活动的关系。结果显示,2001年以来山西5次ML≥5.0地震前均有震源机制趋于一致性现象,震中分布在一致性参数低值附近或高低值过渡区域。Based on the amplitude data of the direct waves recorded by the Shanxi Digital Seismic Network, we calculated the focal mechanism solutions of 281 small to moderate earthquakes from 2001 to 2012 in Shanxi region, by using the fast algorithm of the gener alized transmission coefficient for the point source dislocation model in the layered media. According to the dominant distribution to get average tectonic stress field distribution of Shanxi region, we calculated the consistent parameters of focal mechanism between focal mechanism solutions and stress axis of the corresponding regional tectonic stress field, then analyzed the relationship between the spatial-temporal distribution of consistency parameters and the activity of moderate earthquake. The results show that the focal mecha- nisms before five ML≥5.0 earthquakes since 2001 in Shanxi region all have consistent phe nomena, and the epicenters were located near the low consistency value or in the transition zone of low and high values.

关 键 词：震源机制一致性参数 震源机制解 区域应力场 山西地区 

分 类 号：P315.7[天文地球—地震学]