• 首页关于本刊投稿须知期刊订阅编委会期刊合作English
引用本文:
【打印本页】   【HTML】   【下载PDF全文】   查看/发表评论  【EndNote】   【RefMan】   【BibTex】
←前一篇|后一篇→ 过刊浏览    高级检索
本文已被:浏览 2504次   下载 3158 本文二维码信息
码上扫一扫!
分享到: 微信 更多
用CAP方法研究重庆荣昌2014年2月23日ML3.8地震震源机制
王小龙1) 雷兴林2) 勾宪斌1) 郭欣1) 余国政1)
1) 重庆市地震局,重庆市渝北区红黄路339号401137;2)日本地质调查所,筑波305-8567
摘要:
利用CAP(cut-and-paste)法反演2014年2月23日重庆荣昌ML3.8地震震源机制,得到MW震级为3.04,节面Ⅰ走向46°、倾角44°、滑动角74°,节面Ⅱ走向247°、倾角48°、滑动角104°,P轴方位147.25°、仰角-2.09°,T轴方位46°、仰角-78.76°,表明该地震是带走滑分量的逆冲型地震。CAP 测定的这次ML3. 8 地震的震源深度为3km,在油气的储层内,震源机制解中节面Ⅱ走向、倾角与震中附近的一条深度为1700m 以下走向为SW230°倾向NW,倾角约45°的“腹底”逆断层基本一致。震中位于荣昌天然气田,附近有几口废水回注深井,曾发生大量的注水诱发地震。本次地震亦有可能是在区域主应力场的作用下,注水后岩石的孔隙压发生变化触发了盆地盖层内“腹底”断层活动的结果。
关键词:  荣昌地震  CAP方法  震源机制
DOI:
分类号:
基金项目:中国地震局星火计划(XH14042)、重庆市科技计划项目(cstc2013ggB0011、cstc2014jccxA0028、cstc2014yykfA0234)联合资助
Focal mechanism solution of the February 23,2014,ML3.8 Rongchang earthquake with the CAP (Cut and Paste) method
Wang Xiaolong1) Lei Xinglin2) Gou Xianbin1) Guo Xin1) Yu Guozheng1)
1) Earthquake Administration of Chongqing Municipality,Chongqing 401137,China;2) Geological Survey of Japan AIST,Tsukuba 305 ~ 8567,Japan
Abstract:
A ML3.8 earthquake occurred on February 23,2014,in Rongchang County,which is located at the southern edge of the Sichuan Basin in the border area between Sichuan and Chongqing. This paper presents results of the focal mechanism solution of this earthquake using the CAP (Cut and Paste) method based on broadband seismograms recorded by regional seismic stations in the Chongqing area. Our results showed that the moment magnitude and focal depth are MW3.09,and ~ 3 km,respectively. The hypocenter of this earthquake is located close to a buried fault in the Luoguangshan anticline. Oil prospecting and deep drilling data indicate that this berried fault is a thrust fault,striking SW230°,dipping NW45°,and ~ 1.7km deep. There are some injection wells within the anticline,and significant injection - induced earthquakes were observed during the periods of injection of waste water into the deep formations through those wells. One nodal plane of the best double couple solution of the ML3.8 earthquake shows strike 247°,dip 48°,and rate 104° (46°,44°,74° for another nodal plane),in agreement with the geometry of the buried fault. Therefore,we conclude that the ML3.8 Rongchang earthquake occurred as a result of fault slip along the berried reverse fault reactivated water injection under the compressive stress regime in the area.
Key words:  Rongchang gas field  Cut and Paste method  Focal mechanism