海城盖州地区速度结构和震源位置的联合反演研究

Simultaneous Inversion for Earthquake Hypocenters and Velocity Structure in the Haicheng and Gaizhou Area,Liaoning Province

2012年2月至2013年4月在辽宁盖州地区连续发生了5次4级左右地震,分别为2012年2月2日ML4.7、4.2地震、7月12日ML4.2地震11月1日ML4.0地震以及2013年3月30日ML4.0级地震,地震序列大致呈NW向分布。利用2008年以来盖州地区和海城-岫岩地区的地震观测数据,采用震源位置和速度结构联合反演的软件包Simulps14,给出了两个地区的小震精定位结果和三维速度结构。发现盖州地区震群发生位置较浅,且随时间向西北向展布;其地下速度结构与海城地区地下速度结构存在一定的相似性,分析认为盖州震群是发生在一条类似于大洋河断裂但规模较小的新的断裂带上。

There are several ML4. 0 earthquakes occurred in the Gaizhou area, Liaoning province from Feb. 2, 2012 to Apr. 30, 2013. This earthquake sequence shows a roughly NW-trending distribution. We use earthquake observation reports recorded by regional seismic stations during the period from 2008 to 2013. Through simultaneous inversion method of earthquake hypocenters and velocity structure, we got the earthquake location and velocity structure of Gaizhou and Haicheng area by software Simulps14. The result of earthquake location shows that Gaizhou earthquake warm occurred in a shallower depth, and over time, to the northwest trending. The Gaizhou＇s underground velocity structure is similar to Haicheng＇s underground velocity structure. We think that the Gaizhou earth- quake swarm occurred in a new and smaller fault similar to the Dayanghe fault.