kärst | /kɑːst/
Karst is a German loan word to describe the topography of soluble rocks – typically limestone, dolomite, and gypsum. About 15 percent of the Earth’s land surface is karst. The Germans adopted the term from the karst plateau that straddles the borders of Northern Italy and Southern Slovakia. The Romans had christened the region Carsus, but it was changed to Karst whilst part of the Austro-Hungarian empire. Many of the world’s most recognisable landscapes are karst. The towering peaks of South China and the Causses plateaus of France are karst, as is the Yucatan Peninsula and the vast expanse of Australia’s Nullarbor Plain.
Karst landscapes are formed when rain falling through the atmosphere picks up carbon dioxide. As it passes through soil, it picks up more carbon dioxide, forming a weak carbonic acid that in turn dissolves rocks high in calcium carbonate such as limestone.
As the karstification of a landscape matures, a number of typical features may develop. Caves are emblematic of karst country, the largest of which can be over 200 metres high and hundreds of kilometres long. Dolines are depressions in the surface rock, sometimes many hundreds of metres wide. If they form over a cave, they may collapse into karst craters. Karrens are rocky outcrops scarred with deep crevices sculpted by the surface water. Poljes are large flat-floored basins that may flood to form lakes. Karst pavements can form where glaciers have scraped away surface features to expose horizontal beds of limestone. If the acid rain erodes along relatively straight flowlines, linear fissures appear to cut the rock into pavement-like slabs. Karstification can cause rivers to abruptly disappear into swallow holes (also known as ponors or stream sinks), only to re-emerge downstream as resurgences.
Introduction Aeolian Alpenglow
Benthos Crepuscular Crispate Crown shyness
Desire lines Dreich Endragoned Edgelands
Frondescence Fumarole Gluggaveður Gossamer
Karst Komorebi Lawrence Long acre
Machair Monkey’s wedding Moonglade
Psithurism Quartz Rakuyou Roaring forties
Snag Soft estate Specular, diffuse and pellucid
Spoondrift Steam fog Swash zone Sylvan