Encyclopedia
A
fjord 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 , 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 loaned word taken from the
Scandinavian term
fjord, which derives from the
Old Norse fjörðr meaning firth or inlet. The term
fjord, although commonly used in
Norwegian,
Swedish and
Danish, is not universally used for naming fjords in other countries. Many fjords are called "canals", "inlets" and "sounds" - for example the
Hood Canal,
Burrard Inlet and the
Puget Sound in the
Pacific Northwest.
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 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 .
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. In many cases the only place where villages and farms are established is at the head of the fjord, where a river has formed a delta before entering the sea.Fjords are commonly used as backgrounds for movies.
The circulation of the water in a fjord primarily depends upon the characteristics of the sill created by the terminal morraine and river flow into the fjord. Taller or longer sills can block deep intrusions of ocean water. The sill can also act as a hydraulic control. The deep inner basin of many fjords only gets replenished with new ocean water once a year, which can lead to Anoxic sea water. In addition to the sill, the combination of tides, winds, river flow and ocean density determine how frequently the deep water gets flushed.
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 m has visited it, and even he has only been down three times. The shallowest cold water coral reef in Norway begins at 39 m in
Trondheimsfjord. 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 fjords 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. They can be found 8 m below the surface in Acheron Passage, near
Resolution Island. 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 and mountainous, while others 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 ; 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
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
West coast of North America
West coast of South America
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:
...
Extreme fjords
The longest fjords in the world are:
- Scoresby Sund in Greenland - 350 km
- Sognefjord in Norway - 203 km
- Hardangerfjord in Norway - 179 km
Deep fjords include:
- Skelton Inlet in Antarctica - 1,933 m
- Sognefjord in Norway - ~1,308 m
- Messier Channel in Chile, South America - 1,288 m
Even deeper is the Vanderford Valley , carved by the Antarctica's Vanderford Glacier. This undersea valley lies offshore, however, and so is not a fjord.
Scandinavian usage
Use of the word fjord 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 long narrow freshwater lakes and sometimes even to rivers . In east Sweden 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
fjörður 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 Scandinavian languages are not considered fjords in English; similarly bodies of water which would clearly not be fjords in the Scandinavian 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 Pazincica. 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 , 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
See also
External links
