基于牛顿迭代法求解群速度的地震波射线追踪模拟  

Simulation of seismic ray tracing based on Newton iteration method to solve group velocity

作　　者：张定文 李卫东[1] 段金龙[1] 张学海 ZHANG Dingwen;LI Weidong;DUAN Jinlong;ZHANG Xuehai(College of Information Science and Engineering, Henan University of Technology, Zhengzhou 450001, Henan, China;National Institute of Natural Hazards, Ministry of Emergency Management of China, Beijing 100085, China)

机构地区：[1]河南工业大学信息科学与工程学院,河南郑州450001 [2]应急管理部国家自然灾害防治研究院,北京100085

出　　处：《地震工程学报》2021年第6期1495-1500,共6页China Earthquake Engineering Journal

基　　金：河南省技术创新引导专项(182106000025)。

摘　　要：地下介质中普遍存在着各向异性,当前基于各向异性的地震波射线追踪多是在弱各向异性介质中进行且采用群速度近似表示方法,这些近似方法在强各项异性介质中会导致很大误差而无法真正模拟地震波的传播规律。根据地下普遍存在各向异性的事实和地震波基本传播规律,提出利用牛顿迭代法高效求解群速度,基于Paraview平台自动化构建三维地质模型,采用最短路径法进行地震波射线追踪模拟及可视化,实现对复杂三维地质的速度不均匀性和各向异性的表达,为三维地质模型的构建和地震波射线追踪模拟及可视化提供一种新思路,并以华北克拉通山西断陷带北部局部区域为例进行研究。结果表明,该方法能够减少由各向异性对地震波传播模拟造成的影响,清晰表达了研究区地质结构和各向异性特点,在对复杂三维地质结构的解读中能够较好应用。Anisotropy generally exists in underground media.Nowadays,seismic wave ray tracing based on anisotropy is mostly carried out in weakly anisotropic media by using the approximate formula of group velocity,which will lead to large errors in strongly anisotropic media,and can not really simulate the propagation law of seismic wave.According to the anisotropy in underground media and the basic propagation law of seismic wave,this paper proposed the Newton iteration method for solving the group velocity.Based on the Paraview platform,a 3D geological model was automatically constructed,and the shortest path method was used to simulate and visualize the seismic ray tracing.Taking the northern Shanxi rift zone in the North China Craton as an example,the expression of velocity heterogeneity and anisotropy in complex 3D geology was realized.The experimental results showed that the proposed method can mitigate the influence of anisotropy on seismic wave propagation simulation,clearly express the geological structure and anisotropic characteristics of the study area,so it can be better applied in the interpretation of complex 3D geological structure.

关 键 词：各向异性 群速度 牛顿迭代法 射线追踪 

分 类 号：P631[天文地球—地质矿产勘探]