Acoustic Reverberation at Selected Sites in the Mid-Atlantic Ridge Region,

Abstract

Abstract : Sound scattering from rough surfaces is a very complex phenomenon. Although it has been studied extensively, a full understanding of a three-dimensional scattering function is still lacking. In 1989 the Office of Naval Research (ONR) established the Acoustic Reverberation Special Research Program (ARSRP) whose purpose is to improve this understanding for scattering from the sea surface and the seafloor. As a part of the bottom scattering effort of the ARSRP, researchers from NRL, several universities, and oceanographic institutions have engaged in experimental and theoretical studies of acoustic reverberation in a region of the Mid-Atlantic Ridge (MAR) near 460W, 260N, called the ONR Atlantic Natural Laboratory. Extensive, high- quality, bottom reverberation data were collected in two cruises to the area: ARSRP'91 (also called the Acoustic Reconnaissance Cruise) in the summer of 1991 and ARSRP'93 in the summer of 1993. In these experiments both distant and short-range reverberation data were taken at frequencies around 230 Hz. The RV Cory Chouest worked alone in ARSRP'91. In ARSRP'93 the Cory worked with Wood Hole's RV Knorr and the NATO/SACLANT ship RV Alliance. Here we discuss the character of the short-range (7-18 km) reverberation data collected by the Cory near a sedimented pond, designated as Site A by the ARSRP. (MM)