Computation of Geometric Spreading of Seismic Body Waves in Laterally Inhomogeneous Media with Curved Interfaces

Methods for the calculation of rays and geometrical spreading of seismic body waves propagating in laterally inhomogeneous media with curved interfaces are suggested. Seismic rays and geometric spreading are des-cribed by a system of ordinary differential equations of the first order. When the ray impinges on an interface, certain quantities of the above system change discontinuously. The initial conditions for these quantities at the interface are derived. Once the geometrical spreading has been determined the computation of ray amplitudes is easy. 1