Cite this paper:
LU Zaihua, ZHANG Zhihong, GU Jiannong. Modeling of low-frequency seismic waves in a shallow sea using the staggered grid difference method[J]. HaiyangYuHuZhao, 2017, 35(5): 1010-1017

Modeling of low-frequency seismic waves in a shallow sea using the staggered grid difference method

LU Zaihua, ZHANG Zhihong, GU Jiannong
College of Science, Naval University of Engineering, Wuhan 430033, China
Abstract:
Elastic waves in the seabed generated by low-frequency noise radiating from ships are known as ship seismic waves and can be used to detect and identify ships. To obtain the propagation characteristics of ship seismic waves, an algorithm for calculating seismic waves at the seafloor is presented based on the staggered-grid finite difference method. The accuracy of the algorithm was tested by comparison with analytical solutions. Numerical simulation of seismic waves generated by a low-frequency point sound source in a typical shallow sea environment was carried out. Using various source frequencies and locations in the numerical simulation, we show that the seismic waves in the near field are composed mostly of transmitted S-waves and interface waves while transmitted P-waves are weak near the seafloor. However, in the far field, the wave components of the seismic wave are mainly normal modes and interface waves, with the latter being relatively strong in the waveforms. As the source frequency decreases, the normal modes become smaller and the interface waves dominate the time series of the seismic waves.
Key words:    low frequency|sound source|shallow sea|seismic wavetides|tidal energy|internal tide dissipation|self-attraction and loading tide|Bohai, Yellow and East China Seas (BYECS)   
Received: 2016-02-01   Revised: 2016-04-05
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Articles by LU Zaihua
Articles by ZHANG Zhihong
Articles by GU Jiannong
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