Electrical resistivity tomography combined with previously collected surface wave data in a karst terrain
Jubran, Ryan Joseph
MetadataShow full item record
Two-dimensional electrical resistivity tomography was used to image the subsurface in a karst environment in Albany, GA. Nine electrical resistivity profiles were conducted over previous seismic lines. Apparent resistivity data were inverted and compared with shear-wave velocity models. All profiles show a steep increase in resistivity values (73-123 ohm-m, Line A 156-250 ohm-m) at approximately 10 m indicating a transition from a sandy-clay overburden to limestone bedrock of the Ocala Formation, in agreement with shear-wave velocity models and borehole data. Resistivities for bedrock range from 100-250 ohm-m. A low-resistivity anomaly (56 ohm-m) along Line A and Z corresponds with a previously mapped burn pit. High resistivity anomalies (100-156 ohm-m, 0-10 m depth) correlating with low shear-wave velocity anomalies (200-300 m/s, 0-10 m depth) along three profiles correlate to subsidence features.