Fjord
From Free net encyclopedia
A fjord (or fiord) is a narrow inlet of the sea between cliffs or steep slopes, which results from marine inundation of a glaciated valley. Typical characteristics of a fjord include: a narrow inlet, a bottom glacially eroded significantly below sea level (allowing deep-draft vessels to navigate easily), steep-sided walls which continue to descend below the sea surface, greater depths in the upper and middle reaches than on the seaward side, and communication with the open sea.
Fjord is an English loan word taken from the Scandinavian term fjord, which derives from the Old Norse fjörðr (fjorthr) meaning firth or inlet. The term fjord, although commonly used in Scandinavian speaking countries, is not universally used for naming fjords in other countries. Many fjords are called "canals", "inlets" and "sounds", e.g. Hood Canal and Burrard Inlet in the Pacific Northwest.
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Characteristics
Fjords are found in locations where current or past glaciation extended below current sea level. A fjord is formed when a glacier downwastes, or melts faster than it is moving, after carving its typical U-shaped valley, and the sea fills the resulting valley floor. This forms a narrow, steep sided inlet (sometimes as deep as 1300 m) connected to the sea. Overdeepening of the glacier bed is common, which when combined with the terminal moraine often deposited at the fjord's entrance, usually results in shallower water at the neck of the fjord than in the main body of the fjord. Overdeepenings form near glacier heads or anywhere along the length of a glacier, but are prominent in downglacier reaches (i.e., areas where the glacier dropped significantly tend to be overdeepened at the base of the ice descent).
Fjords commonly have channels which follow the faults of the underlying rock, including occasional sharp corners. The valley at their head, in many cases, extends into the mountains. Sometimes a small residual glacier remains at the valley head. If there is no residual glacier, the river which flows in the valley will begin to build a delta at the head of the fjord; frequently this delta is the best place for farms and villages.
The shallow threshold, great depth and the protection afforded by the valley's sides generally means that fjords are excellent natural harbours. Consequently fjords often provide a home port to fishing fleets, and in industrialised locations have come to be used for fish farming and shipbuilding.
Ancillary features
Coral reefs
As late as 2000, some of the world's largest coral reefs were discovered along the bottoms of the Norwegian fjords. These reefs were found in fjords all the way from the north of Norway to the south. The marine life on the reefs is believed to be one of the most important reasons why the Norwegian coastline is such a generous fishing ground. Since this discovery is fairly new, little research has yet been done. So far, only the deep sea diver who discovered the first reef at 60 meters has visited it, and even he has only been down three times. The reefs are host to thousands of lifeforms such as plankton, coral, anemonies, fish, several species of sharks, and many more one would expect to find on a reef. However most are specially adapted to life under the greater pressure of the water column above it, and the total darkness of the deep sea.
New Zealand's fiords are also host to deep sea corals, but a surface layer of dark fresh water allows these corals to grow in much shallower water than usual. An underwater observatory in Milford Sound allows tourists to view them without diving.
Skerries
In some places near the seaward margins of areas with fjords, the ice-scoured channels are so numerous and varied in direction that the rocky coast is divided into thousands of island blocks, some large & mountainous while others a merely rocky points or rock reefs, menacing navigation. These are called skerries. The term skerry is derived from the old Norse sker, which means a rock in the sea.
Skerries are most commonly formed at the outlet of fjords where submerged glacially formed valleys at right angles with the coast join with other cross valleys in a complex array. The island fringe of Norway is such a group of skerries (called a skjærgård); many of the cross fjords are so arranged that they parallel the coast and provide a protected channel behind an almost unbroken succession of mountainous islands and skerries. By this channel one can travel through a protected passage almost the entire 1,600 km route from Stavanger to North Cape, Norway. The Blindleia is a skerry-protected waterway that starts near Kristiansand in southern Norway, and continues past Lillesand. The Swedish coast along Bohuslän is likewise skerry guarded. The “inside passage” provides a similar route from Seattle, Washington to Skagway, Alaska. Yet another such skerry protected passage extends from the Straits of Magellan north for 800 km.
Locations
Image:Greenland.A2003233.1340.250m-2.jpg
The principal mountainous regions where fjords have formed are in the higher middle latitudes where, during the glacial period, many valley glaciers descended to the then-lower sea level. The fjords develop best in mountain ranges against which the prevailing westerly marine winds are orographically lifted over the mountainous regions, resulting in abundant snowfall to feed the glaciers. Hence coasts having the most pronounced fjords include the west coast of Europe, the west coast of North America from Puget Sound to Alaska, the west coast of New Zealand, and the west coast of South America. Other areas which have lower altitudes and less pronounced glaciers also have fjords or fjord-like features.
West coast of Europe
West coast of New Zealand
- Fiordland, in the southwest of the South Island
West coast of North America
- British Columbia, Canada down to Puget Sound
- The south and west coasts of Alaska in the United States
West coast of South America
- Southern Chile
Other glaciated regions
Other regions have fjords, but many of these are less pronounced due to more limited exposure to westerly winds and less pronounced relief. Areas include:
- Europe
- Ireland (Ireland's only fjord is in Killary Harbour near Leenane, County Galway, on the west coast)
- Scotland (where called firths, the Scots language cognate of fjord; lochs or sea lochs)
- Sweden
- North America
- Canada:
- The south and west coasts of Newfoundland
- The Labrador coast
- The last 100 km of Quebec's Saguenay River
- the Arctic Archipelago
- United States
- Greenland
- Canada:
- Antarctica
- particularly the Antarctic Peninsula
Extreme fjords
The longest fjords in the world are:
- Scoresby Sund on Greenland, (350 km)
- Sognefjord in Norway (203 km)
- Hardangerfjord in Norway (179 km)
Deep fjords include:
- Skelton Inlet, on Antarctica - 1,933 m
- Sognefjord in Norway - ~1,308 m
- Messier Channel in Chile, South America - 1,288 m
Scandinavian usage
Use of the word fjord (including the eastern Scandinavian form fjärd) is more general in the Scandinavian languages than in English. In Scandinavia, fjord is used for a narrow inlet of the sea in Norway, Denmark and western Sweden, but this is not its only application. In Norway the usage is closest to the Old Norse, with fjord used for both a firth and for a long, narrow inlet. In eastern Norway the term is also applied to a long narrow freshwater lake. In Swedish the name fjärd is used in a synonymous manner for bays, bights and narrow inlets on the Swedish Baltic Sea coast, and in most Swedish lakes. This latter term is also used for bodies of water off the coast of Finland where Finland Swedish is spoken. In modern Icelandic fjörðr is still used with the broader meaning of firth or inlet.
False fjords
The differences in usage between the English and the Scandinavian languages have contributed to confusion in the use of the term fjord. Bodies of water which are clearly fjords in Scandanavian languages are not considered fjords in English; similarly bodies of water which would clearly not be fjords in the Scandanavian sense have been named or suggested to be fjords. Examples of this confused usage follow.
The Gulf of Kotor in Montenegro has been suggested by some to be a fjord, but is in fact a drowned river canyon or ria. Similarly the Lim bay in Istria, Croatia, is sometimes called "Lim fjord" although it is not actually a fjord carved by glacial erosion but instead a ria dug by the river Pazinčica. The Croats call it Limski kanal which does not transliterate accurately to the English equivalent either.
Limfjord in the north of Denmark is a fjord in the Scandinavian sense, but is not a fjord in the English sense. In English it would be called a channel, since it separates the island of Vendsyssel-Thy from the rest of Jutland.
While the long fjord-like bays of the New England coast are sometimes referred to as "fiards", the only glacially-formed fjord-like feature in New England is Somes Sound in Maine.
The fjords in Finnmark (Norway), which are fjords in the Scandinavian sense of the term, are considered by some to be false fjords. Although glacially formed, most Finnmark fjords lack the classic hallmark steep-sided valleys of the more southerly Norwegian fjords since the glacial pack was deep enough to cover even the high grounds when they were formed.
Some Norwegian freshwater lakes which have formed in long glacially carved valleys with terminal moraines blocking the outlet follow the Norwegian naming convention; they are named fjords. Outside of Norway, the three western arms of New Zealand's Lake Te Anau are named fjords as well. Another freshwater "fjord" in a larger lake is Baie Fine, located on the northeastern coast of Georgian Bay of Lake Huron in Ontario. Western Brook Pond, in Newfoundland's Gros Morne National Park, is also often described as a fjord, but is actually a freshwater lake cut off from the sea, so is not a fjord in the English sense of the term.
Fjords in culture and history
Fjord horse
There is an ancient breed of horse from the western Norway fjord regions called the fjord horse.
Fjords in literature and popular culture
- Slartibartfast, a character in Douglas Adams's The Hitchhiker's Guide to the Galaxy, is noted for having crafted the fjords in Norway.
- In Monty Python's famous Dead Parrot sketch, Michael Palin asserts that John Cleese's deceased Norwegian Blue parrot is, not dead, but rather "pining for the fjords".
- In a particular episode of Pinky And The Brain, Pinky started to randomly say "fjord!" after Brain named a fjord after him.
See also
External links
- Use of whales to probe Arctic fjord's secrets
- Pictures and info about Norwegian fjords
- More information about Norwegian fjords
- Fiordland's Marine Environment (and corals)
- Gallery of corals and associated marine lifeca:Fiord
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