A boundary element approach to ocean seismoacoustic facet reverberation

A numerically efficient, hybrid method is introduced for modeling of short and long range seismoacoustic facet reverberation in the ocean environment. The method combines the global matrix approach to the solution of the wave equation in horizontally stratified media with a boundary element formulation of the boundary conditions at a contour surrounding the facet. The present paper describes a two-dimensional formulation for facets within an elastic seabed or an elastic ice cover, but allows for simulation of the reverberant field within the water column as well. The approach is directly extendable to treat reverberation from seabed-penetrating facets as well as three-dimensional elastic facets. In contrast to discrete methods such as the finite element and finite difference approaches, the solution obtained with the present hybrid approach is not only efficient for short- as well as long-range reverberation, but inherently decomposes the total solution in the temporal and spatial spectral components, of importance to the basic physical understanding of the factors affecting seismoacoustic facet reverberation.