重庆荣昌诱发地震区精细速度结构及2010年M_L5.1地震序列精确定位  

FINE VELOCITY STRUCTURE AND RELOCATION OF THE 2010 M_L5.1 EARTHQUAKE SEQUENCE IN RONGCHANG GAS FIELD

作　　者：王小龙[1,2] 马胜利[2] 雷兴林[2,3] 郭欣 王强 余国政 勾宪斌 桑原保人 今西和俊 蒋霞东[4] 

机构地区：[1]重庆市地震局,重庆401147 [2]中国地震局地质研究所,地震动力学国家重点实验室,北京100029 [3]日本地质调查所 [4]河海大学常州校区,江苏常州213022

出　　处：《地震地质》2012年第2期348-358,共11页Seismology and Geology

基　　金：中国地震局科技星火计划项目(XH12038Y);地震动力学国家重点实验室开放基金(LED2008B04);重庆市2011年科技计划资助项目(CSTC;2011AC0149)

摘　　要：根据重庆市地震台网和流动地震台网记录到的天然地震资料,利用接收函数反演得到荣昌地区的精细一维速度结构。在此基础上用双差定位法对2010年9月10日重庆荣昌M_L5.1地震序列进行了精定位。结果表明,地震定位精度得到极大提高,震中分布与区域地质构造的关系更加清晰。多数地震集中在主要断层附近并呈条带状分布,震源深度集中在2km附近,与主要储藏层及注水井深度吻合,初步认为该地震序列为注水活动所诱发的构造地震活动。文中获得的精准的速度结构及地震空间分布对于进一步深入研究震区深部地质构造特征、注水诱发地震的机理等具有重要意义。Based on data collected from a temporary seismic network,in addition to some nearby permanent stations,we investigate velocity structure and seismicity in Rongchang gas field,where significant injection-induced seismicity has been identified. First,we use receiver functions from distant earthquakes to invert for detailed 1-D velocity structures beneath typical stations. Then,we use the double-difference hypocenter location method to relocate earthquakes of the 2010 M_L5.1 earthquake sequence occurring at the region. The relocated hypocenters show that the 2010 M_L 5.1 earthquake sequence was distributed in a small area surrounding major injection wells and clustered mostly along pre-existing faults. Major earthquakes show a focal depth less than 5km with a dominant depth of～2km,a depth of major reservoirs and injection wells. We thus conclude that the 2010 M_L 5.1 earthquake sequence might be induced by deep well injection of unwanted water at a depth～3km in Rongchang gas field.

关 键 词：诱发地震 速度结构 接收函数反演 双差定位 荣昌 

分 类 号：P315.2[天文地球—地震学]