GPR measurements for locating underground mine workings at an active open-pit mine

Locating buried voids, tunnels or other openings in the subsurface is one of the more frequently used applications of Ground Penetrating Radar (GPR) (Daniels, 1988). Buried air-filled voids provide an excellent electric permittivity contrast with any rock type. A host rock that is a relatively homogenous and low-loss provides ideal conditions for detecting and delineating subsurface voids. This nearly ideal GPR environment exists in the syenite porphyry rocks at the Zortman Gold Mine in Zortman Montana.