盖州震群重新定位及破裂过程研究

Accurate Relocation and Rupture Process of Gaizhou Earthquake Swarm in Liaoning Province

自2012年2月2日起辽宁省盖州地区发生了多次4级地震,地震活动呈现震群态势。至2016年8月,该震群已活动了4年多的时间,共发生ML≥4.0地震8次,地震空间分布呈现青石岭、西海域、熊岳盆地、营口海域4个地点相互交替活动的态势。盖州震群主要集中在金州断裂九寨—盖县北与盖县北—鞍山南段之间。为了深入研究盖州震群与金州断裂的关系及几个主要地震活动区域之间的相互联系,利用2012-2016年辽宁台网盖州地区的地震观测报告,采用双差定位的方法,得到这个地区的小震精定位结果,结果显示盖州震群几个区域的震群活动均沿北西向分布,其中青石岭震群存在先向西破裂然后向东的阶段性破裂过程,西海域震群存在持续的向两端破裂的过程,营口海域震群可能处于破裂的前期阶段。同时研究发现三个震群之间还存在一定的相关性。

Since February 2nd,2012,a ML≥4 earthquake swarm had been occured in Gaizhou area.The swarm had been active for more than 4 years till August,2016,in which more than 8 times ML≥4.0 earthquakes occured.The earthquake spatial distribution is characterized by the alternation of the 4 sites namely Qingshiling,Xihaiyu,the basin of Xiongyue and Yingkou sea.The earthquake swarm mainly concentrated between the part of Jiuzhai to north Gaixian and north Gaixian to South Anshan in Jinzhou fault.In order to study the relationship between Gaizhou earthquake swarm and Jinzhou fault,and the relationship between the seismic activities,this paper uses the double difference location method to get the result of the small earthquakes,which is based on the report of the Liaoning seismic network in Gaizhou area since 2012.The results show that the seismic activity in several regions of Gaizhou earthquake swarm is distributed along the NW direction.There is a progressive rupture process of the first group to the West and then to the East of Qingshiling swarm.There is a process of continuous rupture to the two ends of the Xihaiyu swarm.Yingkou sea area may be in the early stages of rupture.At the same time,it is found that there is a certain correlation between the three earthquake swarms.