Karst derives from the German word "karst," a limestone plateau near Trieste, Italy.
According to the United Nations Educational, Scientific and Cultural Organization's Global Geoparks Network, karst formation begins with the absorption of carbon dioxide from falling rain. The rainwater acquires more carbon dioxide upon touching the soil and creates carbonic acid. Eventually, the carbonic acid-enriched water breaks down the limestone and dolomite, resulting in openings that increase in size and accelerate karst formation.
According to the Karst Waters Institute, approximately 25 percent of the world's population obtains its water supply from karst.
The United States Geological Survey notes that about 20 percent of the United States' land area contains karst. In addition, karst covers China, Europe, the Caribbean and Australia.
Water mixed with pesticides, petroleum products, animal waste or plastic bags represents the main source of pollution in karst areas. The waste can travel through caves unfiltered and poison the water supply.
In addition, excessive water extraction in populated karst regions can produce sinkholes that swallow office buildings, stores and homes.
