Formation and characteristics
A true fjord is formed when a glacier cuts a U-shaped valley by ice segregation and abrasion of the surrounding bedrock. Fjords are found in locations where current or past glaciation (formation, movement and recession of glaciers) extended below current sea level. A fjord is formed when a glacier retreats, 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 1300m) connected to the sea. The accumulation of glacial debris pushed down into the valley by the glacier is left underwater at the fjord's entrance, causing the water at the neck of the fjord to be shallower than the main body of the fjord behind it.
This shallow threshold and the protection given by the valley's sides generally means that fjords are excellent natural harbours. Fjords often provide a home-port to fishing fleets, and in industrialised locations have come to be used for fish farming and shipbuilding.
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. The reefs are host to thousands of lifeforms such as plankton, coral, anemones, 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 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. An underwater observatory in Milford Sound allows tourists to view them without diving.
Fjords are found all along the coast of:
- West coast of Scotland
- Southwest corner of New Zealand
- West coast of Newfoundland
- British Columbia down to Puget Sound
- South and west coasts of Alaska
- Southern Chile
- Coast of the Baltic Sea in Germany
- Parts of Antarctica, particularly the Antarctic Peninsula
- Various Arctic and Sub-antarctic islands
The longest fjords in the world are:
- Scoresby Sund in Greenland—350 km (217 mi)
- Sognefjord in Norway—204 km (127 mi)
- Independence Fjord in Greenland—200 km (124 mi)
- Matochkin Shar, Novaya Zemlya, Russia—125 km (78 mi)
Deep fjords include:
- Skelton Inlet in Antarctica—1,933 m (6,342 ft)
- Sognefjord in Norway—1,308 m (4,291 ft)
- Messier Channel in Tortel, Chile—1,358 m (4,455 ft)
- Baker Channel in Tortel, Chile—1,251 m (4,104 ft)
When a river reaches a lake or the sea the water slows down and loses the power to carry sediment. The sediment is dropped at the mouth of the river. Some rivers drop so much sediment that waves and tides can't carry it all away. It builds up in layers forming a delta.
Some Norwegian freshwater lakes that have formed in long glacially carved valleys, are frequently named fjords. Ice front deltas developed when the ice front was relatively stable for long time during the melting of the ice shield. The resulting land-form is a narrow strip of land between the lake and the saltwater fjord. Such places are valuable sources of high quality building materials (sand and gravel) for houses and infrastructure.
Some of these lakes were salt after the ice age but later cut off from the ocean during the post-glacial rebound. Some salt water fish got trapped in lakes that originally were part of the salt fjord and gradually became freshwater fish such as the arctic char.
A unique family of freshwater fjords are the bays of the North American Great Lakes. Baie Fine is located on the northwestern coast of Georgian Bay of Lake Huron in Ontario, it is one of the largest freshwater fjords in the world. Huron Bay is located on the southern shore of Lake Superior in Michigan.
Images for kids
Fjord à Christiania by Claude Monet 1895
Eyjafjörður in north Iceland, Akureyri can be seen to the far right
New Zealand's Milford Sound
Glacier in a fjord at Kenai Fjords National Park, Alaska
Norwegian fjord by Kazimierz Stabrowski 1928, National Museum in Warsaw
The calving end of Inostrantsev Glacier at Inostrantsev Fjord, Novaya Zemlya
Fjord Facts for Kids. Kiddle Encyclopedia.