Characterization of a fractured aquifer using multicomponent seismic data

Nine-component seismic equipment from the Network for Earthquake Engineering Simulation (NEES) at the University of Texas is used to determine relationships between seismic and hydrogeologic properties in a near-surface aquifer. The study area is a fractured limestone in the recharge portion of the Edwards aquifer in Hays County south of Austin, Texas. Experiments are developed to measure fracture-related seismic anisotropy and its relationship with the hydrogeologic characteristics of the aquifer. One of the NEES seismic sources is a small vibrator capable of generating waves up to 500 Hz. Three-component data from a traditional hammer source are also recorded. The goal of this study is to estimate in situ fracture parameters of orientation, density, and filling material from seismic data. Estimation of these parameters should be useful for determining groundwater flow and storage, evaluating recharge enhancement, and understanding environmental remediation of fluid contaminants.