GROUND PENETRATING RADAR IN COMPARISON TO ELECTRICAL RESISTIVITY AT WURZBACH BAT CAVE

Central Texas is known for its karst terrain, and there are several shallow karst features in the Austin Chalk Formation. A Ground Penetrating Radar (GPR) survey was taken at Wurzbach Bat Cave in two locations; one over a known section of cave where a skylight was present, and one over a section of unknown depth. The cave was detected in both locations at approximately the same depth. In order to verify the depth of the second location an electrical resistivity system was utilized in a grid formation overlaying the area previously mapped with the GPR . Once this data was collected, analyzed and rendered as 3D images, a comparison was made between the results of the GPR and resistivity systems and a map of the cave to determine which method detected the depth and the extent of the passage most accurately.