A new approach to describe the seismic wavefield using higher order Gaussian beam modes

In the present paper a method is developed to calculate synthetic body wave seismograms using higher order Gaussian beams as a solution of the equation of motion. We obtain an approximated, analytic solution of the equation of motion which is valid in a cone-shaped sector of space. The advantage of this approach is that it is not necessary to perform the beam summation as in the Gaussian beam method. This approach is applied to homogeneous elastic horizontally layered models for the case of near vertical incidence. The computing algorithm is expressed in matrix product form which is convenient for wave modelling. Numerical examples for homogeneous elastic horizontally layered models are given and compared with results obtained by the reflectivity method and a standard ray method.