面波非大圆路径传播研究进展  

Research progress on off-great-circle propagation of surface waves

作　　者：范芮芮 张泽铭 叶庆东[2] 陈浩朋 FAN RuiRui;ZHANG ZeMing;YE QingDong;CHEN HaoPeng(Department of Geodesy and Geomatics Engineering,School of Civil and Transportation Engineering,Guangdong University of Technology,Guangzhou 510006,China;The First Monitoring and Application Center,China Earthquake Administration,Tianjin 300180,China)

机构地区：[1]广东工业大学土木与交通工程学院测绘工程系,广州510006 [2]中国地震局第一监测中心,天津300180

出　　处：《地球物理学进展》2024年第3期990-1002,共13页Progress in Geophysics

基　　金：国家自然科学基金(41804061);广州市基础研究计划基础与应用基础研究专题(2023A04J1526)联合资助。

摘　　要：传统面波层析成像多基于射线理论,并假定面波沿大圆路径传播.由于地球介质的横向非均匀性,面波有时会偏离大圆路径传播,引起面波入射方位角异常和多路径传播效应.本文通过总结面波非大圆路径传播的研究成果,分析了面波非大圆路径传播的主要特点及成因:面波非大圆路径传播效应随着周期的减小而增强,在短周期的非大圆路径传播效应非常明显,地壳上地幔结构的横向非均匀性是导致面波偏离大圆路径传播的主要因素.接着,介绍了测量面波入射方位角异常的两类方法——单台三分量偏振分析和台阵分析方法,其中台阵分析方法相对于单台三分量偏振分析更为可靠和稳定.讨论了面波非大圆路径传播对于面波频散测量和面波层析成像的影响.由于面波的非大圆路径传播,采用天然地震双台法测量的面波频散会高于真实值,而利用背景噪声测量的双台频散会低于真实值.因此,基于大圆路径假设的面波层析成像结果会与真实值出现偏差,特别是各向异性快波方向可能受到的影响更大.最后,本文对面波非大圆路径传播的研究方向进行了展望:在天然地震面波层析成像中,可以利用面波入射方位角异常改正双台面波相速度测量,然后再进行面波层析成像;利用谱元法模拟地震波是研究面波非大圆路径传播的一种有效手段,既需要考虑全球大尺度地壳上地幔结构,也需要考虑研究区内部精细三维结构对于面波非大圆传播的影响.The traditional surface wave tomography isusually based on ray theory and assumes that surface wavespropagate along great-circle paths.Due to the lateralheterogeneity of the Earth's medium,surface waves maydeviate from the great-circle path,causing arrival angleanomalies of surface waves and multi-path propagationeffects.This paper summarizes the research results on theoff-great-circle propagation of surface waves,analyzes themain characteristics and causes of off-great-circlepropagation of surface waves:the off-great-circlepropagation effect of surface waves increases withdecreasing period,being particularly pronounced in shortperiods,and the lateral heterogeneity of the crust-mantlestructure is the main factor leading to the deviation ofsurface waves from great-circle propagation.Then,twotypes of methods for measuring the arrival angle anomaly ofsurface waves are introduced:single-station three-component polarization analysis method and array analysismethod,with the array analysis method being more reliableand stable compared to single-station three-componentpolarization analysis.Due to the off-great-circlepropagation of surface waves,the surface wave dispersionmeasured by traditional two-station method will be higherthan the true value,while the two station ambient noisedispersion will be lower than the true value.Therefore,thesurface wave tomography results based on the great-circleassumption will deviate from the real values.In particular,the anisotropic fast direction of surface waves may be moreaffected.The paper discusses the impact of off-great-circlepropagation of surface waves on surface wave dispersionmeasurements and surface wave tomography,andemphasizes the necessity of considering the off-great-circlepropagation effect of surface waves in high-precisionsurface wave tomography studies.Finally,the paper looks ahead to future research directions in off-great-circlepropagation of surface waves:in event-based surface wavetomography study,the arrival angle anomaly of surfacewaves can be used to correct t

关 键 词：面波层析成像 非大圆路径传播 聚束分析 入射方位角异常 多路径效应 

分 类 号：P315[天文地球—地震学]