任意空间取向TI介质中体波速度特征  

Analysis of body-wave velocity characteristic for TI medium with arbitrary spatial orientation

作　　者：郝重涛[1] 姚陈[1] 

机构地区：[1]中国地震局地质研究所,北京100029

出　　处：《地球物理学报》2007年第2期546-555,共10页Chinese Journal of Geophysics

基　　金：国家自然科学基金项目(40174020;40674023)资助

摘　　要：对于倾斜叠层和非垂直裂隙岩层,用具有任意空间取向对称轴的TI(ATI)模型来描述更符合实际观测.本文基于坐标变换的方法,研究任意强弱ATI介质中体波速度的角散和方位变化特征.研究结果表明,ATI介质中体波速度随传播方向变化的速度图案相对TI对称轴确定,此确定的速度图案与TI的Thomsen参数相关;速度特征只依赖于传播矢量与对称轴的夹角.因此,随着TI对称轴取向的空间变化和测线方位的变化,体波速度图案呈现多样性变化,并具有一定的对称性、渐变和重复性.研究结果有助于进一步的理论研究和各向异性资料处理解释.TI medium with arbitrary spatial orientation （ATI） is the actual anisotropic model used to describe tilted PTL （period thin layers） and no vertical fractured rock. In this paper, we study the characteristic of body-wave velocity with incident angle and azimuth variation by using the method of coordinates transformation for TI medium with arbitrary strength of anisotropy and arbitrary spatial orientation. The result shows that patterns of body-wave velocity are fixed relative to the symmetry axis, and these fixed patterns are closely related to Thomsen＇ s anisotropic parameters. Body-wave velocity characteristic depends just on the angle between the propagation direction and the symmetry axis. Therefore, with variations of spatial orientation of the symmetry axis and the surveying line azimuth, patterns of body-wave velocity show variety, and have some symmetries, gradual changes and repetitions. The result is useful to further theoretical research and explaining of seismic data.

关 键 词：TI介质 任意空间取向 坐标变换 速度特征 

分 类 号：P631[天文地球—地质矿产勘探]