Improved explicit time-domain solution for seafloor seismic wavefield in shallow water

Abstract

The shallow water seafloor seismic wavefield is obtained by the coupled equation of fluid and elastic medium. In the time-domain solution of the coupled equation, for the stability of the explicit time-domain method which is limited by the time step and the accuracy, according to the inverse relationship between the time step and the natural frequency of the system under the stable condition, the unstable modes are removed and according to the criterion of the minimum residual difference under the premise of taking into consideration of the computational efficiency, the optimal step weight value under the three-step is determined. Accordingly, the stable explicit three-step center difference method is proposed. Compared with the classical explicit center difference method, the proposed method has fourth-order accuracy, and its better computational performance is verified and analyzed by using a seafloor seismic wavefield model.