NUMERICAL SEISMOGRAMS OBTAINED USING OMEGA-KAPPA INTEGRALS, FOR A POINT P-SOURCE IN A VERTICALLY INHOMOGENEOUS ANELASTIC MODEL

This article presents some numerical experiments in using a computer p rogram for calculating the displacements due to a P source in a vertic ally inhomogeneous structure, based on the Fourier-Bessel representati on. The structure may contain homogeneous, inhomogeneous, elastic, or viscoelastic layers. The source may act in any type of sublayer or in the half-space. Synthetic results for the simple case of a homogeneous layer overlaying a homogeneous half-space compare favorably with comp utations based on the Cagniard method. Numerical seismograms for an el astic layer having velocities and density varying linearly with depth were computed by integrating numerically the governing differential sy stems and compared with results based on the Haskell model of splittin g the linear layer in homogeneous sublayers. Even an adaptive process with a variable step size based on the Haskell model has a poorer perf ormance on the accuracy-cpu time scale than numerical integration.