  Seafloor topography can excite strong interface waves called Scholte waves
that are often dispersive and characterized by slow propagation but large
amplitude. This type of wave can be used to invert for near seafloor shear wave
velocity structure that is important information for multi-component P-S
seismic imaging. Three different approaches are taken to understand excitation
of Scholte waves and numerical aspects of modeling Scholte waves, including
analytical Cagniard-de Hoop analysis, the boundary integral method and a
staggered grid finite difference method. For simple media for which the Green's
function can be easily computed, the boundary element method produces accurate
results. The finite difference method shows strong numerical artifacts and
stagnant artificial waves can be seen in the vicinity of topography at the
fluid-solid interface even when using fine computational grids. However, the
amplitude of these artificial waves decays away from the seafloor. It is
sensible to place receivers away from the fluid-solid interface for seismic
modeling. To investigate Scholte wave generation, one needs to correctly
implement the fluid-solid boundary condition. It is also shown through
numerical examples including using a seafloor profile from the recent SEG
Advanced Modeling (SEAM) Project that even mild topographic features can
generate Scholte waves and these waves can be used to constrain near seafloor S
wave velocity by dispersion analysis of interface Scholte waves. The
implication to the full waveform inversion is that, although low frequency data
are crucial for convergence, seafloor topography may have a large effect on low
frequency seismic waves.
