HR: 1330h
AN: NS23B-15    [Abstracts]
TI: Sinkhole Imaging With Multiple Geophysical Methods in Covered Karst Terrain
AU: * Weiss, M
EM: mwise00@hotmail.com
AF: University of South Florida, 4202 East Fowler Ave, Tampa, FL 33620 United States
AB: A suite of geophysical surveys was run at the Geopark at the University of South Florida campus in Tampa in attempt to determine the degree to which methods could image a collapsed sinkhole with a diameter of ~4m and maximum depth of ~2.5m. Geologically, the Geopark is part of a covered karst terrane, with collapsed sinkholes filled in by overlying unconsolidated sand separated from the weathered limestone beneath by a clayey sand layer. The sinkholes are hydrologically significant as they may serve as sites of concentrated recharge. The methods used during the study include: refraction seismics, resistivity, electromagnetics (TEM and EM), and ground penetrating radar (GPR). Geophysical data are compared against cores. The resistivity, GPR, and seismic refraction profiles yield remarkably consistent images of the clayey sand layer. EM-31 data revealed regional trends in subsurface geology, but could not delineate specific sinkhole features with the desired resolution.
DE: 0694 Instrumentation and techniques
DE: 0994 Instruments and techniques
DE: 7294 Instruments and techniques
SC: Near-Surface Geophysics [NS]
MN: 2005 Joint Assembly