物探与化探2024，Vol.48Issue(4)：986-995,10.DOI:10.11720/wtyht.2024.1387
地震面波和P—导波正演模拟与波场分析
Forward modeling and wave field analysis of seismic surface waves and guided P-waves
摘要
Abstract
Surface waves and guided P-waves,as two boundary-related wave phenomena,are a crucial part of the near-surface seismic wave field.This study investigated their generation mechanism and propagation regularity using the high-order staggered-grid finite-difference algorithm.First,it solved the problems like numerical dispersion and boundary conditions in numerical simulation.Based on this,it designed medium models under different thicknesses and elastic parameters for forward modeling.Furthermore,it extracted dis-persion profiles and amplitude versus offset curves for analysis.In the case of a low-velocity thin layer on the surface,guided P-waves can be generated when the phase velocities of P and SV waves from the same source exceed the S-wave velocity but are less than the P-wave velocity of the underlying high-velocity layer.In media with high Poisson's ratios(＞0.4),the phase velocities of surface waves and guided P-waves are sensitive to the S-and P-wave velocities,respectively.Surface waves and guided P-waves usually contain near-sur-face information that is unavailable in refracted and reflected waves.The appropriate acquisition,analysis,and inversion of near-surface information enable the establishment of a high-resolution near-surface model.This study generalized the generation conditions and wave field characteristics of surface waves and guided P-waves under the same source and deepened the understanding of their propagation regularity,laying a foundation for inversion and denoising research.关键词
面波/P—导波/数值模拟/产生条件/波场分析Key words
surface wave/guided P-wave/numerical simulation/generation condition/wave field analysis分类
天文与地球科学引用本文复制引用
刘童,孙成禹,蔡瑞乾..地震面波和P—导波正演模拟与波场分析[J].物探与化探,2024,48(4):986-995,10.基金项目
国家自然科学基金项目"基于石油勘探面波与P—导波的近地表纵横波速度一体化反演"(42174140)、国家自然科学基金青年项目"黏弹各向异性介质复杂震源机制解析与微地震响应高精度正演"(42004113) （42174140）
