【摘要】 应用现代适配滤波频时分析技术对SRO/GDSN长周期面波记录进行处理,获得穿过太平洋盆地的117条波路径的勒夫波频散数据。我们用改进的分格频散反演方法,从混合路径频散数据中提取出对应于构成整个太平洋盆地的10°×10°分格的纯路径频散数据。所获得的18s到215s范围内的28个周期的太平洋勒夫波群速度的横向分布,揭示了速度随海底年龄的增大而逐渐增加的总趋势,以及其它变化细节。例如,对于同一等年龄线区而言,北太平洋及南太平洋的群速度要比中太平洋的低0.1—0.3km/s。在分格模型反演的基础上得出的深至300km的三维剪切波速度结构提供了太平洋盆地地壳及上地幔横向不均匀性的详尽的描述。更多还原

【Abstract】 In this study, Love wave dispersion data of 117 selected wave paths crossing the Pacific ocean basin are determined by applying the MF-FTAN technique to SRO/GDSN long period data. An improved grid dispersion inversion method is proposed to extract pure-path dispersion curves over all 10° ×10° composing grids from the mixed-path dispersion data for a more extensive study. The lateral distributions of Love wave group velocities in the Pacific for 28 periods in the range of 18 to 215 seconds have been obtained which indicate a progressive increase in velocity with respect to the increasing age of the sea floor and other detailed features. For instance, the group velocities in the north and south Pacific are relatively lower than that in the central Pacific by 0.1 to 0.3 km/s for the same isochron. The three dimensional shear velocity structure to a depth of 300 km constructed on the basis of the grid model inversion provides a detailed description on the lateral heterogeneities in the Pacific crust and upper mantle.更多还原