Modal Investigation of Elastic Anisotropy in Shallow Water Environments: A Study of Anisotropy Beyond VTI

摘要

This paper presents theoretical and numerical results for the modal characteristics of the seismo-acoustic wavefield in generally anisotropic range- independent media. General anisotropy affects the form of the elastic stiffness tensor, which directly affects the polarization of the local modes, the frequency and angular dispersion curves, and also introduces the effects of nearly degenerate modes. Horizontally polarized shear motion plays an important role in seismo-acoustic wave propagation in shallow water environments, and will be important for proper analysis of sediment attenuation. The transverse particle motion cannot be ignored when anisotropy is present for low frequency modeshaving significant bottom interaction. Even in 1-D media an explosion source excites particle motion in all three directions.