地震地质 ›› 2012, Vol. ›› Issue (2): 348-358.DOI: 10.3969/j.issn.0253-4967.2012.02.013

• 研究论文 • 上一篇    下一篇

重庆荣昌诱发地震区精细速度结构及2010年ML5.1地震序列精确定位

王小龙1,2, 马胜利2, 雷兴林2,3, 郭欣1, 王强1, 于国政1, 勾宪斌1, 桑原保人3, 今西和俊3, 蒋霞东4   

  1. 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, 筑波 305-8567;
    4. 河海大学常州校区, 江苏常州 213022
  • 收稿日期:2011-03-14 修回日期:2012-04-20 出版日期:2012-06-30 发布日期:2012-07-12
  • 基金资助:
    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)和重庆市2011年科技计划资助项目(CSTC,2011AC0149)共同资助

FINE VELOCITY STRUCTURE AND RELOCATION OF THE 2010 ML5.1 EARTHQUAKE SEQUENCE IN RONGCHANG GAS FIELD

WANG Xiao-long1,2, MA Sheng-li2, LEI Xing-lin2,3, GUO Xin1, WANG Qiang1, YU Guo-zheng1, GOU Xian-bin1, KUWAHARA Yasuto3, IMANISHI Kazutoshi3, JIANG Xia-dong4   

  1. 1. Chongqing Earthquake Administration, Chongqing 401147, China;
    2. State Key Laboratory of Earthquake Dynamics, Institute of Geology, China Earthquake Administration, Beijing 100029, China;
    3. Geological Survey of Japan, Tsukuba, 305-8567, Japan;
    4. Hohai University, Changzhou, Changzhou 213022, China
  • Received:2011-03-14 Revised:2012-04-20 Online:2012-06-30 Published:2012-07-12

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ML5.1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。

关键词: 诱发地震, 速度结构, 接收函数反演, 双差定位, 荣昌

Abstract: 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 ML5.1 earthquake sequence occurring at the region. The relocated hypocenters show that the 2010 ML 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 ML 5.1 earthquake sequence might be induced by deep well injection of unwanted water at a depth~3km in Rongchang gas field.

Key words: induced earthquake, receiver function, double difference location, Rongchang

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