Journal of Shanghai Jiaotong University ›› 2018, Vol. 52 ›› Issue (12): 1627-1633.doi: 10.16183/j.cnki.jsjtu.2018.12.012

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Components and Propagation Characteristics of Seabed Seismic Waves

MENG Luwen, LUO Xiayun, CHENG Guangli, ZHANG Mingmin   

  1. 1. 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

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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