Geometrical characteristics of phase and group velocity surfaces in anisotropic media

The phase and group velocity surfaces are essential for wave propagation in anisotropic media. These surfaces have certain features that, especially, for shear waves result in complications for modelling and inversion of recorded wavefields. To analyse wave propagation in an anisotropic model, it is important to identify these features in both the phase and group domains. We propose few characteristics for this analysis: the energy flux angle, decomposed in the polar and azimuth angle correction angles and enhancement factor, which is able to characterize both singularity points and triplication zones. The very simple equation that controls the triplications is derived in the phase domain. The proposed characteristics are illustrated for elastic and acoustic anisotropic models of different symmetry classes.

Automated summary

The phase and group velocity surfaces play a crucial role in wave propagation in anisotropic media, especially for shear waves. It is important to identify features in both the phase and group domains to analyze wave propagation in an anisotropic model. The proposed characteristics, such as the energy flux angle and enhancement factor, help characterize singularity points and triplication zones in anisotropic models.