Why do sinkholes appear?

The UK seems to be suffering from a plague of sinkholes. In the past month alone a 15ft hole has opened up on the M2, a 30ft crater swallowed a car in High Wycombe and in Hemel Hempstead, homes were evacuated after a sinkhole 35ft across opened up in a residential street. read more

There are two basic types, those that are created slowly over time (a cover-subsidence sinkhole) and those that appear suddenly (a cover-collapse sinkhole). Naturally, it’s the latter type that create headlines, but both varieties are formed by the same basic mechanism. read more

Why They Appear Sinkholes most commonly occur in karst terrain: regions where limestone, gypsum, salt beds, or other carbonate rock can be dissolved. Water eats away at the rock until a pit is formed. read more

A sinkhole, also known as a cenote, sink, sink-hole, swallet, swallow hole, or doline, is a depression or hole in the ground caused by some form of collapse of the surface layer. Most are caused by karst processes—for example, the chemical dissolution of carbonate rocks or suffosion processes. Sinkholes vary in size from 1 to 600 m both in diameter and depth, and vary in form from soil-lined bowls to bedrock-edged chasms. Sinkholes may form gradually or suddenly, and are found worldwide. read more