重庆地区Lg波衰减、台站场地响应与ML震级测定  

Lg-Wave Attenuation,Station Site Response and M L Determination in Chongqing Region

作　　者：汪建 朱新运 邵媛媛[3] 杨亚运 熊成 向涯 Wang Jian;Zhu Xinyun;Shao Yuanyuan;Yang Yayun;Xiong Cheng;Xiang Ya(Chongqing Earthquake Agency,339 Honghuang Road,Chongqing 401147,China;Zhejiang Earthquake Agency,7 Tangmiao Road,Hangzhou 310013,China;Liaoning Earthquake Agency,44 North-Huanghe Street,Shenyang 110031,China;Guangdong Earthquake Agency,81 Mid-Xianlie Road,Guangzhou 510070,China;Institute of Seismology,CEA,40 Hongshance Road,Wuhan 430071,China;Key Laboratory of Earthquake Geodesy,CEA,40 Hongshance Road,Wuhan 430071,China)

机构地区：[1]重庆市地震局,重庆市401147 [2]浙江省地震局,杭州市310013 [3]辽宁省地震局,沈阳市110031 [4]广东省地震局,广州市510070 [5]中国地震局地震研究所,武汉市430071 [6]中国地震局地震大地测量重点实验室,武汉市430071

出　　处：《大地测量与地球动力学》2023年第6期633-640,共8页Journal of Geodesy and Geodynamics

基　　金：重庆市地震局科技创新课题(CQDZQN202308)。

摘　　要：选取2010~2020年重庆数字地震台网36个台站记录的127次M_(L)≥3.0地震波形资料,利用Lg波衰减参数与台站场地响应联合反演方法,得到l~7 Hz频率内Lg波三分向(UD,EW,NS)与频率f的衰减关系分别为Q UD(f)=173.6 f^(0.77)、Q_(EW)(f)=154.9 f^(0.78)、Q_(NS)(f)=157.6 f^(0.73)。结果表明,研究区属于低Q_(0)值和较高频率依赖性的构造活跃区。计算36个测震台站的场地响应,结果显示,大多数台站的幅值曲线较为平滑,各台站之间的场地响应存在差异,其中SHG台、PAL台和JIP台的场地响应曲线在部分频段内存在异常放大现象。选取642次M_(L)≥2.0地震观测报告,对有放大效应的台站作场地响应校正后,大多数台站更靠近台网平均震级,CQT台、SHG台和HCB台校正效果明显,部分台站介质衰减对地震波振幅的影响大于场地响应。We select the waveform data of 127 M_(L)≥3.0 earthquakes recorded by 36 stations of Chongqing digital seismic network from 2010 to 2020.Using the joint inversion method of Lg-wave attenuation parameters and station site response,we obtain the attenuation relationship between the three directions of Lg-wave(UD,EW,NS)at the frequency of l to 7 Hz,which is Q UD(f)=173.6 f^(0.77),Q_(EW)(f)=154.9 f^(0.78),Q_(NS)(f)=157.6 f^(0.73).The study area is a tectonic active area with low Q_(0)value and high frequency dependence.We calculate the site responses of 36 seismic stations.The results show that the amplitude curve of most stations is relatively smooth,and the site responses of each station are different.Among them,the site response curves of SHG,PAL and JIP stations have abnormal amplification in some frequency band.We select the seismic observation reports of 642 M_(L)≥2.0 to correct the site response of stations with amplification effect.The average magnitude of most stations is closer to the average magnitude of the network,the correction effect of CQT,SHG and HCB stations is obvious,and the influence of medium attenuation of some stations on seismic wave amplitude is greater than that of site response.

关 键 词：LG波 衰减参数 场地响应 联合反演 震级偏差 

分 类 号：P315[天文地球—地震学]