Download or read book A Geophysical Study of Subsurface Paleokarst Features and Voids at Ohio Caverns, Champaign County, Ohio written by Laura M. Scaggs and published by . This book was released on 2014 with total page 174 pages. Available in PDF, EPUB and Kindle. Book excerpt: Ground penetrating radar (GPR), electrical resistivity and seismic refraction surveys were used to image possible buried sinkholes and identify potential areas of subsidence in the shallow paleokarst surface of the Columbus Limestone at Ohio Caverns in Champaign County, Ohio. A buried sinkhole, incipient sinkholes and a possible buried cave passage spatially correlated with orthoimagery and surface evidence of subsidence. Correlations were established by using GIS software overlaying a structure-contour map of the paleokarst, as determined by GPR data, over orthoimagery of the area. Wenner and dipole-dipole electrical resistivity surveys suggest regions of lower resistivity surrounded by higher resistivity are associated with suspected subsidence. Refraction seismic data, collected along the same transect as the resistivity surveys, also correlated with an area of depression in the region of a suspected sinkhole. The seismic velocities from the refraction survey indicated lower depths for the clay soil and Ohio Shale contact and also the boundary between the Ohio Shale and the Columbus Limestone. Remote sensing using electrical resistivity, GPR and seismic refraction techniques successfully imaged the stratigraphy of the area and suggest other areas of incipient sinkhole formation.