What is Karst?
The term karst is defined as "terrain with distinctive landforms and drainage arising from greater rock solubility in natural water than is found elsewhere" (Jennings, 1985). The word karst itself is a German adaptation of the Slavic word kras and the Italian word carso. The word is a recent addition to the English language, as there was no existing word for this specific type of landscape. An estimated 10% of the earth's surface is characterized by karst terrain and one-quarter of the world's population in supplied by karst water (www.gcrio.org).
Karst areas are very distinct landscapes in their surface features, lithology, and drainage patterns. Surfacially, karst landscapes can vary from relatively low-relief as in temperate climates to containing large conical karst towers found in areas of the tropics. No matter how drastic the landscapes may appear, they were created primarily by dissolution. Many karst areas are characterized by soluble bedrock such as limestone, gypsum, and dolomites to name a few (Ritter, D.F., et. al.).
Karst bedrocks have an abundance of joints and fractures within them. The joints enlarge due to solution processes brought on by direct rainfall and runoff water percolating through the bedrock.
Limestone jointing enhanced by the processes of solution through rainwater, also known as limestone pavement.
http://www.woodhey.bury.sch.uk/html/curric/human/Malham2003/disc3/Limestone%20Pavement%204/
Water is stored in underground reservoirs and travels through an underground network of streams and springs. Crevasses within the bedrock continue to enlarge due to solution over time until they are exposed to open air from the atmosphere above the surface. Once surface air is introduced into the cave environment, the solution process is reversed. The calcite is precipitated, leading to the formation of drip stones along cracks and joints. Three of these features are stalactites, stalagmites, and columns. Stalactites are spike-like features that form on the ceilings of caves and are built downward.
Stalactites forming on a cave ceiling. www.goodearthgraphics.com/.../ staltite.html
Stalagmites are also spike-like columns, but are built from the cave floor up. Stalagmites also usually occur under cracks and joints. After prolonged periods of accumulation, some stalactites and stalagmites meet, forming features known as columns. Columns extend from the roof to the floor of the cave.
Stalagmites, stalactites, and columns formed in a cave filled with water. www.bluewaterdivers.com/ Gallery/Akumal03/
Large dissolving gaps on bedrock can form intricate networks of cave systems within the bedrock. The largest cave system in the world in located in south central Kentucky and is known as the Mammoth Cave System. It stretches over 350 miles (560 km) and in protected by the National Parks Service.
Entrance to Mammoth Cave National Park-Kentucky (Taken by Matt Below)
The four stages of the karst erosional cycle
Karst lands are found all throughout the world. Some places include areas of China, Yugoslavia, England, Australia, and the United States. In the US, large bands of karst terrain are found in the east and central parts, while scattered smaller bands are found west of the Mississippi River (Ritter, D.F., et .al.).
Karst areas of the United States shown in Green.
Links: Mammoth Cave Nat'l Park-http://www.nps.gov/maca/home.htm
Karst Links Page-http://hum.amu.edu.pl/~sgp/spec/linkk.html
