A sinkhole is the result of erosion of the subsurface. When underground water dissolves carbonate bedrock such as limestone, dolomite, or other soluble rock it creates subterranean passages, cavities and caves. This irregular, subsurface rock topography is known as karst. These voids in the bedrock are inclined to sudden surface collapses (sinkholes). Sinkholes can also occur in areas with soft soil, in mining areas, or where some other subsurface disturbance has occurred.
Human activities which accelerate sinkhole formation
Locating sinkholes and subsidence without digging, probing, or drilling can be accomplished using non-destructive field surveys. The two main methods for detecting sinkholes are aerial photography and geophysical procedures.
Various geophysical investigation techniques can be used in Karst terrains including ground penetrating radar, electrical conductivity, electrical resistivity, magnetic field, very low frequency measurement (ELF), gravity field recording and seismic velocity measurements.