Utilization of high-frequency Rayleigh waves in near-surface geophysics

The shear (S)-wave velocity of near-surface materials (such as soil, rocks, and pavement) and its effect on seismic wave propagation are of fundamental interest in many groundwater, engineering, and environmental studies. The Kansas Geological Survey conducted a three-phase research project to estimate near-surface S-wave velocity from ground roll: acquisition of ground roll, creation of algorithms that extract Rayleigh wave dispersion curves from ground roll, and development of algorithms to obtain near-surface S-wave velocity profiles. The research project has been expanded to analyze 1) the effects of higher modes on inversion of surface waves and investigation depth and 2) the feasibility of estimation of near-surface quality factor (Q) by inverting attenuation coefficients of Rayleigh waves. This paper summarizes these research results