In the study of seismic wave scattering, most of the research is based on the assumption of far-field and plane wave incidence, which is applicable to the far-field case, but cannot describe the near-field seismic wave scattering well. Based on this problem, we propose scattering equations suitable for near-field scattering. Unlike the far-field, in the near-field condition, the source is not far from the receiving point, the incident wave is no longer a plane wave, but a spherical wave. Therefore, our study of near-field scattering is based on the spherical wave incidence under the assumption of Born approximation. By processing the near-field displacement equation, the scattering expressions of spherical P-wave and spherical S-wave are obtained, respectively. It can be found by the scattering expressions, the near-field scattering wave is only related to and but not to of the reference medium, this is different from the far-field scattering theory. Finally, the spatial scattering patterns varying depending upon various combinations of density and elastic-constant perturbations are given to show the behavior of different equivalent forces of the near-field seismic scattering.
Presentation Date: Wednesday, September 18, 2019
Session Start Time: 1:50 PM
Presentation Time: 1:50 PM
Location: 225C
Presentation Type: Oral
