【摘要】 本文采用随机介质描述地球内部大尺度背景场上存在的小尺度不均匀性和自组织结构;文中没有采用传统的层状网格结构,提出了块状结构来描述复杂的二维自组织结构的方法,分别以高斯型、指数型和vonKarman型等自相关函数描述各向同性和各向异性非均匀分布自组织特征;采用射线追踪分析了不同分布特征自组织结构对地震波运动学和动力学特征参数的影响;结果表明,由于地球内部介质的自组织性存在,地震波射线轨迹可能发生明显的畸变;不同偏移距处,地震反射振幅减弱或增强;自组织结构从高斯型到vonKarman型,在小尺度上表现更大的非均匀性,因此走时和振幅表征依次更强的平均效应.更多还原

【Abstract】 We utilize random media to describe small-scale inhomogeneity and self-organized structure in the Earth interior. A block model is adopted to describe the self-organized structure instead of traditional grids in 2-D. Gaussian, exponential, and von Karman autocorrelation functions are used to represent the isotropic and anisotropic self-organized structure. We use numerical methods to perform ray tracing and rectify amplitudes by dynamic ray tracing, furthermore, analyze the influence upon the kinematic and dynamic characteristics of seismic waves. The results indicate that seismic ray trajectories probably generate significant aberrances and the amplitudes of seismic rays may weaken or enlarge at different offsets for the existence of the self-organized structure in the earth interior; from Gaussian to von Karman, amplitudes present more obvious statistic characters.更多还原