四川木里小震群活动特征研究  

The Active Characteristics of Small Earthquake Swarms in the Muli Area of Sichuan Province

作　　者：蔡一川[1] 戴仕贵[1] 魏娅玲[1] 

机构地区：[1]四川省地震局,成都610041

出　　处：《震灾防御技术》2015年第4期933-940,共8页Technology for Earthquake Disaster Prevention

基　　金：中国地震局测震台网青年骨干培养专项(专题编号:20140320;20140321)

摘　　要：本文通过对四川木里地区地震震源位置的重新确定,反演了地震震源机制解,结果显示:1重定位后的小震群震中分布成带状,地震震源深度分布在0—12km范围内;2经过对震群空间分布进行仔细分析,认为其发震构造是小金河断裂西侧的一条NWW向分支断裂;33次4.0级以上地震震源参数存在明显差异,浅源逆冲事件表现出受垂直方向应力(重力)作用的特征,走滑事件表现出与区域应力构造活动有关。In this article, we relocated the seismic source location of the Sichuan Muli areas earthquakes, and inverted the focal mechanism of those larger earthquakes. The relationship between the water level of the Jinping reservoir and the frequency of the earthquake swarm was analyzed. The results showed that: 1)The epicenter of the relocated small earthquake swarm distributes into seismic zone, and the earthquake focal depth is in the range of 0—12 km.(2)By analyzing the earthquake swarm spatial distribution, we found that the earthquake swarms are generated from one branch fault on the west Xiaojin fault;(3)The focal mechanism of three earthquakes with magnitude greater than 4.0 is significantly different, in which the shallow source thrust events are effected by the vertical stress, and the strike-slip events are related to regional tectonic activity.

关 键 词：震群活动 地震条带 双差定位方法 震源机制 

分 类 号：P315.5[天文地球—地震学]