Beschreibung:
Previous studies of the propagation of sound through an ocean wedge with a penetrable bottom [beginning with F. B. Jensen and W. A. Kuperman, J. Acoust. Soc. Am. 67, 1564–1566 (1980)] have been restricted to the case of an isovelocity fluid wedge and bottom. Consequently, for upslope propagation through the wedge, where all modes successively cut off down to the last one, the sound energy refracts into the bottom at each mode cutoff point, travels downward, and gets lost in the depths. In contrast, it is shown here that if (as is often the case) the sediment possesses a positive sound-speed gradient, the sound refracted into the bottom beyond its mode cutoff in the water wedge may continue traveling upslope in the sediment below the water, hence carrying ocean-originated acoustic information closer to shore where it may be registered by bottom-mounted receivers.