Reflection of seismic waves at oblique angles from deep sea sediments

Abstract

The theory of oblique-angle seismic reflectivity, as applied to oceanographic research, is presented. An experiment has been developed in which continuous oblique reflection profiles were made by towing an acoustic source behind a ship and listening with a hydrophone suspended beneath a free-floating radio buoy. Information received at the hydrophone was transmitted to the ship and recorded on magnetic tape. Energies of the bottom-reflected signals have been calculated for varying angles of incidence and the corresponding reflectivities produced. Results from the Tyrrhenian Sea and from north of Puerto Rico indicate the possibility that the sound velocity in the first-layer sediments is less than the sound velocity of the bottom water.