Joint Inversion for Apparent Phase Velocities of Rayleigh and Love Waves

Many surface-wave methods have focused on collecting only normal modes of Rayleigh-wave propagation. This paper presents an inversion algorithm to invert the apparent phase velocities, which include near-field information as well as normal-mode information. In the algorithm, Love-wave dispersion data are jointly included with Rayleigh-wave dispersion data to reduce non-uniqueness inherent in surface-wave methods and increase the accuracy of a resulting shear-wave velocity profile. Synthetic dispersion data were generated for typical geologic sites, and used for the verification of the inversion algorithm. A strategy to overcome the adverse effects of multiple reflections and mode conversion in Love waves is also discussed.