【摘要】 对2001年昆仑山口西Ms8.1级地震产生的断层带,布设了沿断层和横跨断层的两条人工地震测线.通过对观测资料的定量分析和处理,求得了昆仑山断层带内部的细结构.分析工作包括从S波震相开始的振幅谱计算、速度频散计算、群速度测量,并用面波频散方法反演S波速度结构,用振幅谱比的方法估计断层带的Q值.野外试验结果表明,S波震相与围陷波组的时间差随炮点与台站之间距离增大而增加,在断层带外的测点上观测到与断层带相关的场地效应.最后得出昆仑山断层带宽度为250m、速度结构为断层内低速的分层结构和Q值为15(断层内)和30(围岩).虽然昆仑山口西地震的震级比美国加州Landers地震的震级(Ms7.6)大,且地震产生的破裂带长度长得多,但是这两个地震断层带的宽度却相差不大.更多还原

【Abstract】 Artificial seismic experiment was deployed on the fault zone generated by the Kunlun M-s8.1 earthquake on Nov.4,2001.The seismic data recorded on two profiles,one along and the other across the fault zone,were analyzed and processed for investigation of the fine structure of the fault zone with the guided wave trapped in fault zone.The analysis includes amplitude spectra calculation,group velocity and dispersion curves extraction,S wave velocity structure inversion with surface wave methods and the estimation of Q with an amplituderatio method.The result of field experiment reveals that the time delay between the S wave and trapped wave train increases with the epicentral distance.The site effect related to the fault zone is also observed in seismograms recorded on the stations located out of the fault zone.The final result suggests that the fracture zone of Kunlun fault is about 250m wide,and has a layered internal velocity structure and an average Q of 15,while the average Q of wall rocks is 30.It is also found that the width of rupture zone generated by the Kunlun earthquake is the same as that of Landers,California,M-s7.6 earthquake,although both of the magnitude and the length of fracture zone of the former are much larger than those of the latter.更多还原