HR: 0830h
AN: S41B-03    [Abstracts]
TI: Elastic Scattering from a Quarter Space; Numerical Tests
AU: * Lindwall, D
EM: lindwall@nrlssc.navy.mil
AF: Naval Research Laboratory, Code 7432, Stennis Space Center, MS 39529 United States
AB: We are investigating elastic and acoustic wave scattering from an elastic quarter space within water. Understanding rough surface scattering is critical for marine seafloor acoustics. The simplest scattering is from a two-dimensional edge. Within an elastic quarter space we observe multiple downward-scattered and transmitted phases including transmitted P and S waves, P and S head waves, P and S diffracted waves, and interface waves. The forward and backward scattered waves in the water can originate from the direct water wave as well as converted wave phases within the quarter space. At some locations in the water, there are as many as four distinct arrivals. In many seafloor survey systems, some of these diffracted waves could be interpreted as coming from more distant scattering points on the seafloor or from sub-seafloor volume scattering points, hence leading to incorrect interpretations of the observed data.
DE: 0935 Seismic methods (3025)
DE: 7203 Body wave propagation
DE: 7260 Theory and modeling
SC: Seismology [S]
MN: 2005 Joint Assembly