M.S Thesis: Three-Dimensional Finite-Difference Methods For Seafloor Scattering

Nizar Chemingui

For the purpose of simulating large-scale seafloor scattering for general heterogeneous media using an elastic finite-difference scheme, I develop new tools for modeling explosive point sources and pressure plane waves traveling at given angle of incidence and for efficiently simulating a free surface on a staggered grid. The absorbing boundary conditions and finite-difference scheme were chosen to minimize memory requirements, a vital consideration for three-dimensional simulations. In addition, the algorithms are designed with large amounts of parallelism, making them suitable for modern computers and feasible tools for Monte Carlo investigations.

Using these tools, I simulate scattering from a Goff-Jordan seafloor model with self-similar bathymetry. The results underscore the importance of fully elastic modeling in understanding the origin and strength of the reverberatory coda not present for smooth, planar seafloor models.