Friday, 4 July 2014
Geologically, a fjord is a long, narrow inlet with steep sides or cliffs, created by glacial erosion. The word comes to English from Norwegian, but related words are used in several Nordic languages, in many cases to refer to any long narrow body of water other than the more specific meaning it has in English. There are many fjords on the coasts of Norway, Iceland, Greenland, Alaska, British Columbia and Chile. A fjord is formed when a glacier cuts a U-shaped valley by ice segregation and abrasion of the surrounding bedrock. Glacial melting is accompanied by the rebounding of the Earth's crust as the ice load and eroded sediment is removed (also called isostasy or glacial rebound). In some cases this rebound is faster than sea level rise. Most fjords are deeper than the adjacent sea; Sognefjord, Norway, reaches as much as 1,300 m below sea level. Fjords generally have a sill or shoal (bedrock) at their mouth caused by the previous glacier's reduced erosion rate and terminal moraine. In many cases this sill causes extreme currents and large saltwater rapids. Saltstraumen in Norway is often described as the world's strongest tidal current. Source
