长白山天池火山区上地壳三维速度层析成像  

3D TOMOGRAPHY OF VELOCITY STRUCTURE IN THE UPPER CRUST BENEATH THE CHANGBAISHAN TIANCHI VOLCANIC REGOIN

作　　者：赵金仁[1] 张先康[1] 杨卓欣[1] 张成科[1] 王夫运[1] 张建狮[1] 刘宝峰[1] 段玉玲[1] 王帅军[1] 

机构地区：[1]中国地震局地球物理勘探中心,郑州450002

出　　处：《地球物理学报》2003年第6期796-802,共7页Chinese Journal of Geophysics

基　　金：国家基础研究 973项目 (G19980 40 70 2 );中国地震局"九五"重点项目 ( 95 -11-0 2 -0 1)资助 ;中国地震局地球物理勘探中心论著编号RCEG 2 0 0 2 0 9

摘　　要：利用三维地震透射观测系统所获得的莫霍界面反射波对长白山天池火山区下方上地壳的三维速度细结构进行了反演计算 ,得到了研究区下方地壳内不同深度的P、S波速度层析成像和VP VS 扰动分布图像 ,结果表明 ,天池火山区及其周边速度结构所呈现出的非均匀性变化与该区的地质构造和岩浆系统的存在有着密切的关系 ,异常变化比较明显的低P波速度异常体分布和高VP VS 扰动体意味这些介质体处在“软化高温”的状态 ,这与该地区广泛分布的地热异常和低Q值结构的研究结果是一致的 .We obtain P-and S-wave velocity tomography and V p/V S perturbation images at different depths beneath the Changbaishan Tianchi volcanic region by three-dimensional velocity structure inversion. The inversion is based on reflected waves from Moho recorded by the 3D seismic transmission observational system in the studied area. The result shows that the heterogeneity of velocity structure beneath the Tianchi volcanic region and its surrounding areas is closely related to the geological structure and existence of magma systems in the area. The obvious anomalous bodies of low-velocity P-wave and high V p/V S perturbation imply that these media are in a “softened and high-temperature” state. This is consistent with the result of wide-spread geothermal anomaly and low Q-value structure.

关 键 词：三维地震透 三维速度细结构 反演 速度层析成像 扰动分布图像 上地壳细结构 

分 类 号：P315[天文地球—地震学]