各向同性介质中射线理论与有限差分地震波场模拟方法比较研究  

Comparison of ray theory and FDM for simulating seismic wavefield in isotropic media

作　　者：王涛[1,2] 白超英[1,3] 杨尚倍 

机构地区：[1]长安大学地质工程与测绘学院,西安710054 [2]陕西铁路工程职业技术学院,渭南714099 [3]长安大学计算地球物理研究所,西安710054

出　　处：《地球物理学进展》2016年第2期606-613,共8页Progress in Geophysics

基　　金：国家科技重大专项子课题(2011ZX05024-001-03)资助

摘　　要：地震波场数值模拟不仅是研究复杂地区地震资料采集、处理和解释的有效辅助手段,而且是研究地球深部精细构造和地球深部探测的有效工具.射线理论和波动方程理论是地震波场数值模拟的理论基础.射线理论主要刻画地震波在介质中传播的走时场、地震射线等运动学属性;波动方程理论通过求解波动方程来描述地震波在介质中传播的弹性动力学响应(能量衰减、相位特征、偏振属性、以及全波形等).基于波动方程理论的波场数值模拟由于能够引入丰富的波场信息,使得人们对不同介质中地震波的传播过程有了较全面的了解.本文以二维层状均匀介质模型为例,通过射线追踪法和交错网格有限差分法模拟得到的波场快照图、单炮地震记录剖面、合成理论地震图的分析比较,不但对地震波在各向同性层状均匀介质中的传播规律和特点有了深刻的理解和认识,同时又可以相互验证两种不同方法的正确性和有效性.Seismic numerical modeling method is an important tool,not only for sampling,processing and interpretation of seismic data in complex media,but also for investigating accurate structure of the earth＇s interior.The ray theory and elastic wave equation are two basic numerical simulation methods for seismic wavefield. Ray theory mainly depicts the kinematics properties of seismic wave propagation,such as traveltime field,ray trajectory. While,the wave equation theory describes elastic dynamic response of wave propagation, such as, energy attenuation, phase character,polarization property and full waveform. The numerical simulation method based on the elastic wave equation can obtain more detailed seismic wavefield and hence bring deep and fully understanding of seismic wave propagation in different media. Through the analysis and comparison of wave-field snapshot, common source gather seismic profile,synthetic seismogram by using two different methods（ one ray tracing method and the other is a high-order staggered-grid finite difference method）, it is not only capable of thoroughly understanding the wave propagation laws,but also able to verify the accuracy and efficiency of each method.

关 键 词：射线追踪法 有限差分法 地震波传播 数值模拟 各向同性介质 

分 类 号：P631[天文地球—地质矿产勘探]