上海佘山地震台阵地壳精细结构研究  

Detailed crustal structure in Shanghai Seismic Array

作　　者：贾思超 吴珊珊 钟卫星[1,2] 叶青[1,2] 肖爽 于海英[1,2] JIA Sichao;WU Shanshan;ZHONG Weixing;YE Qing;XIAO Shuang;YU Haiying(Shanghai Earthquake Agency,Shanghai 200062,China;Shanghai Sheshan Geophysical National Field Observation and Research Station,Shanghai Earthquake Agency,Shanghai 200062,China)

机构地区：[1]上海市地震局,上海200062 [2]上海市地震局上海佘山地球物理国家野外观测研究站,上海200062

出　　处：《地震地磁观测与研究》2024年第5期20-27,共8页Seismological and Geomagnetic Observation and Research

基　　金：中国地震局地震科技星火计划(项目编号:XH240902A)。

摘　　要：选取上海佘山地震台阵16个子台记录的远震波形数据,采用时间域反褶积方法计算不同频率的P波接收函数,采用H-κ叠加搜索方法获取每个子台下方地壳厚度和v_(P)/v_(S)波速比值。研究结果显示:整个台阵下方地壳厚度和波速比值存在弱横向不均一性,其中上海佘山地区平均莫霍面深度较浅,约26.9 km;v_(P)/v_(S)比值较高,约1.87。采用最小二乘法联合多频率P波接收函数和瑞利频散曲线,反演上海佘山地震台阵下方地壳S波速度结构,结果显示,中地壳存在S波低速结构,与前人研究结果相一致。In this paper,the teleseismic waveform data recorded at 16 sub-stations of the Sheshan Seismic Array in Shanghai are selected,and the time-domain deconvolution method is used to calculate the P-wave receiver functions at different frequencies,and the H-κstacking method is used to obtain the thickness of the crust beneath each sub-station and the v_(P)/v_(S) ratio.The results show that there are weak lateral inhomogeneities in crustal thickness and v_(P)/v_(S) ratio beneath the whole array,with the average Moho surface depth in the Sheshan region of Shanghai being thin,about 26.9 km,and the v_(P)/v_(S) ratio being high,about 1.87.The inversion of the S-wave velocity structure of the crust beneath the Sheshan Seismic Array is performed by using the least-square method in combination with the multi-frequency P-wave receiver functions and Rayleigh dispersion curves,and the results show that there is an S-wave low-velocity structure in the middle crust,which is consistent with the results of previous studies.

关 键 词：接收函数 地壳厚度 v_(P)/v_(S)波速比 联合反演 

分 类 号：P315.7[天文地球—地震学]