Difference between revisions of "Fjord" - New World Encyclopedia
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The seeds of a fjord are laid when a [[glacier]] cuts a [[U-shaped valley]] through [[Abrasion (geology)|abrasion]] of the surrounding [[bedrock]] by the sediment it carries. Many such valleys were formed during the recent [[ice age]]. At the end of such a period, the [[climate]] warms and glaciers retreat. [[Sea level]] rises due to an influx of water from melting [[ice sheet]]s and glaciers around the world inundating the vacated valleys with seawater to form fjords. | The seeds of a fjord are laid when a [[glacier]] cuts a [[U-shaped valley]] through [[Abrasion (geology)|abrasion]] of the surrounding [[bedrock]] by the sediment it carries. Many such valleys were formed during the recent [[ice age]]. At the end of such a period, the [[climate]] warms and glaciers retreat. [[Sea level]] rises due to an influx of water from melting [[ice sheet]]s and glaciers around the world inundating the vacated valleys with seawater to form fjords. | ||
| − | It is believed that the glaciers that formed in these valleys were so thick and heavy that they eroded the bottom of the valley far below sea level before they floated in the [[ocean]] water. After the glaciers melted, the waters of the sea invaded the valleys.<ref name=EB> ''Encyclopædia Britannica Online'', 2008, | + | It is believed that the glaciers that formed in these valleys were so thick and heavy that they eroded the bottom of the valley far below sea level before they floated in the [[ocean]] water. After the glaciers melted, the waters of the sea invaded the valleys.<ref name=EB> ''Encyclopædia Britannica Online'', 2008, Fjord. /ref> |
Glacial melting is also accompanied by a rebound in the earth's crust as the ice load is removed. In some cases this rebound may be faster than the sea level rise. Most fjords are, however, deeper than the adjacent sea; [[Sognefjord]], Norway, reaches as much as 1,300 m (4,265 ft) below sea level. Fjords are often very deep in their upper and middle reaches, although they generally have a sill or rise at their mouth associated with the previous glacier's [[terminal moraine]]. These characteristics distinguish fjords from [[ria]]s (such as the [[Bay of Kotor]]), which are drowned valleys flooded by the rising sea. | Glacial melting is also accompanied by a rebound in the earth's crust as the ice load is removed. In some cases this rebound may be faster than the sea level rise. Most fjords are, however, deeper than the adjacent sea; [[Sognefjord]], Norway, reaches as much as 1,300 m (4,265 ft) below sea level. Fjords are often very deep in their upper and middle reaches, although they generally have a sill or rise at their mouth associated with the previous glacier's [[terminal moraine]]. These characteristics distinguish fjords from [[ria]]s (such as the [[Bay of Kotor]]), which are drowned valleys flooded by the rising sea. | ||
Revision as of 15:35, 21 January 2023
A fjord (or fiord) is a long, narrow deep inlet of the sea bordered by steep cliffs. Fjords commonly extend far inland and are extremely deep in their upper and middle reaches. Norway's Hardangerfjord drops to 2,624 feet (800 m) below sea level, while the depth of Sogn Fjord (also Norway) measures 4,290 feet (1,308 m) deep, and Canal Messier in Chile is 4,167 feet (1,270 m). The great depth of these submerged valleys is due to their glacial origins.
The seeds of a fjord are laid when a glacier cuts a U-shaped valley through abrasion of the surrounding bedrock by the sediment it carries. Many such valleys were formed during the recent ice age. At the end of such a period, the climate warms and glaciers retreat. Sea level rises due to an influx of water from melting ice sheets and glaciers around the world inundating the vacated valleys with seawater to form fjords.
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. The only areas near a fjord where people can settle are deltas formed at the mouths of rivers.
The word "fjord" comes from Old Norse, fjörðr, meaning a "lake-like waterbody used for passage and ferrying."
Geology
The seeds of a fjord are laid when a glacier cuts a U-shaped valley through abrasion of the surrounding bedrock by the sediment it carries. Many such valleys were formed during the recent ice age. At the end of such a period, the climate warms and glaciers retreat. Sea level rises due to an influx of water from melting ice sheets and glaciers around the world inundating the vacated valleys with seawater to form fjords.
It is believed that the glaciers that formed in these valleys were so thick and heavy that they eroded the bottom of the valley far below sea level before they floated in the ocean water. After the glaciers melted, the waters of the sea invaded the valleys.Cite error: Closing </ref> missing for <ref> tag
Notes
ReferencesISBN links support NWE through referral fees
- Hurdle, Burton G. The Nordic seas. New York: Springer-Verlag, 1986. ISBN 978-0387962412
- Roy, Iain. Beyond the imaginary gates: journeys in the fjord region of north-east Greenland. Stockport: Dewi Lewis, 2004. ISBN 978-1904587064
- Seaman, Paul, and Bjørn Buchardt. The columns of ikaite tufa in Ikka Fjord, Greenland. Meddelelser om Grønland, 44. Copenhagen: Danish Polar Center, 2006. ISBN 978-8790369804
External links
All links retrieved April 12, 2017.
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