1. 军事科学院 国防科技创新研究院， 北京 100071； 2. 海军工程大学 电子工程学院， 武汉 430033
通讯作者:张明敏，男，教授，博士生导师.E-mail: zhangmm_hg@126.com.作者简介:孟路稳（1990-），男，河南省汝南县人，博士生，助理研究员，研究方向为水声物理、水声信号与信息处理.基金资助:国家自然科学基金资助项目（41576105）Components and Propagation Characteristics of Seabed Seismic Waves
MENG Luwen, LUO Xiayun, CHENG Guangli, ZHANG Mingmin1. National Defense Science and Technology Innovation Institute, Academy of Military Sciences, Beijing 100071, China； 2. College of Electronic Engineering, Naval University of Engineering, Wuhan 430033, China
摘要/Abstract
摘要： 为获取海底地震波波动成分及其传播特性，将两层半无限液固海洋模型中的波场表示成复积分的形式，采用鞍点法求解波场复积分的远场近似解，并阐述了与积分解相对应的波动成分及其传播特性.结果表明：海底界面处存在的波动成分包括直达声波、反射声波、侧面波、透射纵波、透射横波、泄漏瑞利波和Scholte波；其中直达声波、反射声波和透射波的波阵面为球面，侧面波的波阵面为圆锥面，Scholte波的波阵面为圆柱面.并应用高阶交错网格有限差分法对以上各种波的传播过程进行了数值模拟，给出了场量的波场快照，形象直观地显示出空间中存在的波动成分及其传播特性，数值模拟结果与理论分析结论相吻合.
关键词: 海底地震波, 复积分, 鞍点法, 有限差分
Abstract: To obtain components and propagation characteristics of seabed seismic waves, the wave field in the two-layer semi-infinite liquid-solid ocean model is expressed in the form of complex integral. The far-field approximation solution of the wave field complex integral is obtained by using the saddle point method. The wave components corresponding to the integral solution and its characteristics are then presented. Results show that the wave components at the seabed interface are direct acoustic wave, reflected acoustic wave, lateral wave, transmitted longitudinal wave, transmitted transverse wave, leaky Rayleigh wave and Scholte wave. The wavefronts of the direct acoustic wave, reflected acoustic wave and transmitted waves are spherical, and those of the lateral wave and Scholte wave are conical and cylindrical respectively. In addition, the high-order staggered-grid finite difference method is applied to simulate the wave propagation process, and wave field snapshots are shown. The wave components and their propagation characteristics are visually displayed. The numerical simulation results are in good agreement with the theoretical analysis.
Key words: seabed seismic wave, complex integral, the saddle point method, finite difference
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