What is a sink hole?

Answer by  tamarawilhite (17883)

A sink hole is formed when a cavity that has formed under the surface of the earth erodes to the surface or the ground collapses into the cave. Then a sink hole erupts on the surface as the ground sinks into this new hole. This usually occurs in areas with lots of limestone.

Answer by  Mable (3008)

They occur when the land surface caves in to a hollow beneath it: the hollow may natural or carved by water. Size varies: my aunt was walking across her lawn once and sank to her hips; another developed in a highway near home and was filled first with compacted autos.

Answer by  catman529 (809)

A sinkhole is a hole in the ground that is caused by an underground cavity, often eroded by rainwater, that collapses from the top. A limestone sinkhole is slowly eroded by acid rainwater, and eventually the underground cavity becomes so big that the top falls out and forms a sinkhole.