重庆地区背景噪声面波群速度层析成像  

Surface Wave Group Velocity Tomography of Background Noise in Chongqing Area

作　　者：魏红梅 陈丽娟 王同军 WEI Hongmei;CHEN Lijuan;WANG Tongjun(Chongqing Earthquake Agency,Chongqing 401147,China)

机构地区：[1]重庆市地震局,重庆401147

出　　处：《华南地震》2020年第1期46-52,共7页South China Journal of Seismology

基　　金：地震监测、预测、科研三结合课题(CEA-JC/3JH-162201);地震监测、预测、科研三结合课题(3JH-202001072)。

摘　　要：选取重庆、四川、湖北、湖南及贵州测震台网共25个固定台站2015年3~9月的连续地震背景噪声记录,利用互相关方法获得瑞利面波的格林函数,再用时频分析方法提取瑞利面波的群速度频散曲线,最后用面波层析成像方法反演得到重庆地区深度为5~20 km的S波速度图像。成像结果表明重庆地区浅部地壳S波速度结构存在横向不均匀性;S波速度异常与研究区内断裂构造分布有较好的相关性,基底埋深较浅的山脉地区为高值异常区。This paper selected the continuous seismic background noise records from March to September 2015 recorded by 25 fixed stations in Chongqing,Sichuan,Hubei,Hunan,and Guizhou.The cross-correlation method was used to obtain the Green's function of the Rayleigh surface wave,and the group velocity dispersion curve of the Rayleigh surface wave was extracted by time-frequency analysis method.Finally,the surface wave tomography method was used to invert the S-wave velocity images in Chongqing with a depth of 5-20 km.The imaging results show that the S wave velocity structure of shallow crustal in Chongqing area has lateral heterogeneity.There is a good correlation between the S wave velocity anomalies of Rayleigh wave and the distribution of fault structures in the study area.The mountain area with shallow basement is a high value anomaly area.

关 键 词：背景噪声 互相关 格林函数 群速度频散 面波层析成像 重庆地区 

分 类 号：P315.7[天文地球—地震学]