Geophysical applications to detect sinkholes and ground subsidence

The term sinkhole receives a lot of use, and equal amounts of abuse, in the popular media. Generally, anytime a hole or depression forms in the land surface, sometimes in a short period of time, it is called a sinkhole. Sinkholes are geologic features formed by movement of rock or sediment into voids created by the dissolution of water-soluble rock. Some sinkholes, such as the infamous Winter Park, Florida, sinkhole of 1981 (Figure 1), capture the attention of society as we view expensive homes and automobiles teetering on a precipice about to disappear into the underworld. Subsidence features caused by other processes, such as mine collapse and washouts resulting from broken water and sewer mains, are not true sinkholes, but may be equally as damaging. These features also result from rock or soil moving into a void, but the void was a result of human activities