利用微动方法研究吉林市浅层二维剪切波速度结构  

Two-dimensional shear wave velocity structure of the shallow crust studied by the microtremor survey

作　　者：李洪丽[1] LI Hongli(College of Geo-exploration Science and Technology,Jilin University,Changchun 130026,China)

机构地区：[1]吉林大学地球探测科学与技术学院,长春130026

出　　处：《物探化探计算技术》2020年第5期563-568,共6页Computing Techniques For Geophysical and Geochemical Exploration

基　　金：深地资源勘查开采重点专项(2018YFC0603701)。

摘　　要：本研究在吉林市某工区布设短周期地震仪,用于记录该地区五个观测目标点连续15个小时的地震背景噪声数据。采用微动方法(空间自相关)提取观测点瑞雷面波相速度频散曲线,再利用面波层析成像方法反演得到了该区域一维剪切波(S波)结构,进而获得了该地区1000 m深度以内的二维S波速度结构剖面。速度剖面成像结果显示,研究区域地下1000 m以内整体分为三层,在第三层中存在两个低速度异常(550 m^950 m),推测为富含水区,为该区域开展地热探测、野外地质调查等综合研究提供重要参考。In this study,a dense array of short-period seismometers was set up in an industrial area of Jilin city to record the ambient noise data of five observed target points for 15 consecutive hours.The microtremor survey(spatial autocorrelation)was used to extract the phase velocity dispersion curve of rayleigh surface wave at the observation point,and the one-dimensional shear wave(s-wave)structure in this region was obtained by inversion of surface wave tomography,and then the two-dimensional S-wave velocity profile within a depth of 1000m was obtained.The velocity structures showed that the whole area within 1000m underground was divided into three layers,including two low velocity anomalies in the third layer(550-950m),which were speculated to be rich water area.This result provides an important reference for the comprehensive research of geothermal exploration and field geological survey in this region.

关 键 词：微动方法 反演 剪切波速度结构 面波 

分 类 号：P315[天文地球—地震学]