Measurements of the effects of bottom slope on sound propagation in shallow water

Abstract

Laboratory scale measurements have been made of sound propagation in shallow water over a sloping bottom. The measurements were made in a large test pool in a water layer over a model of the ocean floor that consisted of an epoxy layer on a concrete base. The properties of the model were consistent with those found in typical ocean sediments and substrates. The results presented in this paper will demonstrate downslope- and across-slope propagation for several different bottom angles, and comparisons will be made with measurements in a uniform depth water column over the same bottom. Important differences were found even in the special case of across slope propagation where the water depth was constant with range. Shadow zones and modal absorption will be demonstrated. [Work supported by ONR.]