Drilling a seismic borehole for the National Seismic Network at Mendenhall Laboratory on the main campus of The Ohio State University, Columbus, Franklin County, Ohio. Sprowls Drilling Company of Sunbury, Ohio, did the drilling work for the borehole. At a depth of 125 feet, in the Columbus Limestone, a cavern was encountered. An unsuccessful attempt was made to plug the cavern. The site was abanonded as a location in the United States Geological Survey's nationwide network of seismographs because of the condition of the limestone on the campus of The Ohio State University. The image was taken by Michael C. Hansen in August 1993.
