A STUDY OF SEISMIC ACOUSTIC-WAVE PROPAGATION THROUGH A LATERALLY VARYING MULTILAYERED MEDIUM USING THE BOUNDARY-INTEGRAL-EQUATION DISCRETE-WAVE-NUMBER METHOD

In this paper the boundary-integral-equation method is employed along an acoustic/elastic interface of a seabed. The line source Green's fun ctions are based on a discrete-wave-number representation of an infini te acoustic ocean and a discrete-wave-number representation of the hor izontally stratified elastic bottom. The bottom Green's function, whic h adds in the elastic wave-field contributions of the horizontally str atified layers, is computed by the method of reflectivity and transmis sivity matrices. In this paper the developed algorithm has been used t o study scattering from irregular acoustic/elastic interfaces at ultra sonic frequencies. One model has been compared with real data collecte d in an ultrasonic modeling tank. The final section of this paper addr esses the scattering of two acoustic/elastic rough interface models ov erlying a stack of solid layers with increasing velocity profile. The first seabed model has a syncline-shaped interface and the second is a syncline with a superposed sinusoidal component.