Fjord
In physical geography, a fjord is a long, relatively narrow sea inlet with steep sides or cliffs in a valley created by a former glacier, which has since become inundated with water. They are the glacial equivalent of drowned river valleys, known as rias. Fjords exist on the coasts of Antarctica, the Arctic, and surrounding landmasses of the northern and southern hemispheres. Areas with extensive fjords demonstrate an extreme example of the coastline paradox: Norway's coastline is estimated to be 29,000 km (18,000 mi) long with its nearly 1,200 fjords, but only 2,500 km (1,600 mi) long when excluding the fjords.
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