• 首页关于本刊投稿须知期刊订阅编委会期刊合作查看检索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 1489次   下载 1860 本文二维码信息
码上扫一扫!
分享到: 微信 更多
2012 年天津宝坻2 次有感地震的力学机制研究
刘双庆1) 高原2) 张磊1,3) 汪翠枝1) 马建英1)
1)天津市地震局,天津市河西区友谊路19 号300201;2)中国地震局地震预测研究所,北京100036;3)中国矿业大学(北京),北京100083
摘要:
利用地震仪器烈度分布、地震记录初动极性分布、近场地震序列Sg 震相剪切波分裂特征、震中附近应变仪器记录及深井气氦记录等,综合分析了宝坻地区2012 年MS 4. 0、MS 3. 5两次有感地震。研究发现,这2 次地震震级不大,但孕震过程可能伴有地下介质应力状态的变化,表现出震前半年北东东向加速压缩、北北西向拉张至MS3. 5 地震后该状态转缓的动态过程。2 次地震间隔期间地下积累应力疑似没有得到充分释放,地下微裂隙局部调整使得该地深井观测的稀有气体出现高值,MS 3. 5 地震后微裂隙重新闭合,稀有气体恢复背景值,同时地震剪切波快波方位角恢复到北东东向的背景方向。震中区附近的形变、测震、流体等观测异常有一定的时空对应性。
关键词:  剪切波分裂  仪器烈度  初动极性  地震孕育过程
DOI:
分类号:
基金项目:中国地震局测震星火计划项目( XH14002Y )、骨干青年专项( 20130202 )、天津市国土局项目(1212011220232 - 5)、山东省局重点科研基金项目( JJ1309Y)联合资助
Study on the mechanical process of 2 noticeably felt earthquakes in Baodi County,Tianjin in 2012
Liu Shuanqing1) Gao Yuan2) Zhang Lei1,3) Wang Cuizhi1) Ma Jianying1)
1) Earthquake Administration of Tianjin Municipality,Tianjin 300201,China;2) Institute of Earthquake Science,China Earthquake Administration,Beijing 100036,China;3) China University of Mining & Technology,Beijing 100083,China
Abstract:
In terms of the instrument intensity distribution,first impulse orientation of seismic velocity records,Sg shear wave split characteristics of a serial of near-regional earthquakes and records of strain and helium gas in deep holes nearby epicenter,we discuss two noticeably felt earthquakes of MS4. 0 and MS3. 5 in Baodi County in 2012 and reveal some gestation traits of these earthquakes. Although the magnitudes of 2 earthquakes are a little small,some stress changes may appeare in the crust in seismogenic process,in the form of an accelerated NEE orientation pressure and NNW dilation half a year before main earthquake. These states alleviated after MS3. 5. In the time interval between two earthquakes,the regional underground accumulated stress may not be fully released. The state change of local underground micro-cracks led to record more deep rare gas. After MS3. 5 micro-cracks closed again,the polarization azimuth of seismic quick shear wave returned to the NEE direction. In the near epicenter region,the abnormal characteristics of strain record,seismogram and deep hole liquid had a certain consistence of observation in time and space.
Key words:  Shear wave split  Instrument intensity  First impulse orientation  Seismogenic process