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Outwash
An outwash plain, also called a sandur (plural: ''sandurs''), sandr or sandar, is a plain formed of glaciofluvial deposits due to meltwater outwash at the terminus of a glacier. As it flows, the glacier grinds the underlying rock surface and carries the debris along. The meltwater at the snout of the glacier deposits its load of sediment over the outwash plain, with larger boulders being deposited near the terminal moraine, and smaller particles travelling further before being deposited. Sandurs are common in Iceland where geothermal activity accelerates the melting of ice flows and the deposition of sediment by meltwater. Formation Sandurs are found in glaciated areas, such as Svalbard, Kerguelen Islands, and Iceland. Glaciers and icecaps contain large amounts of silt and sediment, picked up as they erode the underlying rocks when they move slowly downhill, and at the snout of the glacier, meltwater can carry this sediment away from the glacier and deposit it on a broad plai ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Glaciofluvial Deposits
Glaciofluvial deposits or Glacio-fluvial sediments consist of boulders, gravel, sand, silt and clay from ice sheets or glaciers. They are transported, sorted and deposited by streams of water. The deposits are formed beside, below or downstream from the ice. They include kames, kame terraces and eskers formed in ice contact and outwash fans and outwash plains below the ice margin. Typically the outwash sediment is carried by fast and turbulent fluvio-glacial meltwater streams, but occasionally it is carried by catastrophic outburst floods. Larger elements such as boulders and gravel are deposited nearer to the ice margin, while finer elements are carried farther, sometimes into lakes or the ocean. The sediments are sorted by fluvial processes. They differ from glacial till, which is moved and deposited by the ice of the glacier, and is unsorted. Ice-contact deposits A subglacial megaflood may cut cavities into the base of the ice. As the flood dies down, sediment is deposited ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Kettle Lake
A kettle (also known as a kettle lake, kettle hole, or pothole) is a depression/hole in an outwash plain formed by retreating glaciers or draining floodwaters. The kettles are formed as a result of blocks of dead ice left behind by retreating glaciers, which become surrounded by sediment deposited by meltwater streams as there is increased friction. The ice becomes buried in the sediment and when the ice melts, a depression is left called a kettle hole, creating a dimpled appearance on the outwash plain. Lakes often fill these kettles; these are called kettle hole lakes. Another source is the sudden drainage of an ice-dammed lake. When the block melts, the hole it leaves behind is a kettle. As the ice melts, ramparts can form around the edge of the kettle hole. The lakes that fill these holes are seldom more than deep and eventually fill with sediment. In acid conditions, a kettle bog may form but in alkaline conditions, it will be kettle peatland. Overview Kettles are fluviog ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Skeiðarársandur
Skeiðarársandur () is an Icelandic glacial outwash plain, a vast expanse of sand generated by the transport of debris by the Skeiðará and other rivers, whose flow is generated by the Skeiðarárjökull glacier and fed by the volcanic systems of Grímsvötn and Öræfajökull. The coastline of the Sandur is 56 km long (from Hvalsík to Hnappavallaós). From Skeiðarárjökull, the valley glacier of Vatnajökull, to the sea is 20–30 km. The Skeiðará was the most important obstacle in the construction of Iceland's Route 1. It was not until 1974 that it could be completely closed by a 904 m long bridge. This is currently the longest bridge in Iceland. It was temporarily destroyed by water masses and blocks of ice during the last major glacial outburst flood in 1996, triggered by an eruption of the Grímsvötn volcano, but was immediately restored. The outwash plain originated primarily as alluvial land, i.e. as an accumulation of sediments from the rivers. ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Glacier
A glacier (; ) is a persistent body of dense ice that is constantly moving under its own weight. A glacier forms where the accumulation of snow exceeds its Ablation#Glaciology, ablation over many years, often Century, centuries. It acquires distinguishing features, such as Crevasse, crevasses and Serac, seracs, as it slowly flows and deforms under stresses induced by its weight. As it moves, it abrades rock and debris from its substrate to create landforms such as cirques, moraines, or fjords. Although a glacier may flow into a body of water, it forms only on land and is distinct from the much thinner sea ice and lake ice that form on the surface of bodies of water. On Earth, 99% of glacial ice is contained within vast ice sheets (also known as "continental glaciers") in the polar regions, but glaciers may be found in mountain ranges on every continent other than the Australian mainland, including Oceania's high-latitude oceanic island countries such as New Zealand. Between lati ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Grímsvötn
Grímsvötn (; ''vötn'' = "waters", singular: ) is a volcano with a (partially subglacial) fissure system located in Vatnajökull National Park, Iceland. The volcano itself is completely subglacial and located under the northwestern side of the Vatnajökull ice cap. The subglacial caldera is at , at an elevation of . Beneath the caldera is the magma chamber of the Grímsvötn volcano. Grímsvötn is a basaltic volcano which has the highest eruption frequency of all the volcanoes in Iceland and has a southwest-northeast-trending fissure system. The massive climate-impacting Laki fissure eruption of 1783–1784 was a part of the same fissure system. Grímsvötn was erupting at the same time as Laki during 1783, but continued to erupt until 1785. Because most of the volcanic system lies underneath Vatnajökull, most of its eruptions have been subglacial and the interaction of magma and meltwater from the ice causes phreatomagmatic explosive activity. Jökulhlaup Eruptions in the cal ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Vatnajökull
Vatnajökull ( Icelandic pronunciation: , literally "Glacier of Lakes"; sometimes translated as Vatna Glacier in English) is the largest and most voluminous ice cap in Iceland, and the second largest in area in Europe after the Severny Island ice cap of Novaya Zemlya. It is in the south-east of the island, covering approximately 8% of the country. Size With an area of 7,900 km2, Vatnajökull is the second largest ice cap in Europe by volume (about 3,000 km3) and area (after the still larger Severny Island ice cap of Novaya Zemlya, Russia, which is in the extreme northeast of Europe). On 7 June 2008, it became a part of the Vatnajökull National Park. The average thickness of the ice is , with a maximum thickness of . Iceland's highest peak, Hvannadalshnúkur (), as part of the Öræfajökull, is in the southern periphery of Vatnajökull, near Skaftafell. Volcanoes Under the ice cap, as under many of the glaciers of Iceland, there are several List of volcanoes in Ice ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Icelandic Language
Icelandic (; is, íslenska, link=no ) is a North Germanic language spoken by about 314,000 people, the vast majority of whom live in Iceland, where it is the national language. Due to being a West Scandinavian language, it is most closely related to Faroese, western Norwegian dialects, and the extinct language, Norn. The language is more conservative than most other Germanic languages. While most of them have greatly reduced levels of inflection (particularly noun declension), Icelandic retains a four- case synthetic grammar (comparable to German, though considerably more conservative and synthetic) and is distinguished by a wide assortment of irregular declensions. Icelandic vocabulary is also deeply conservative, with the country's language regulator maintaining an active policy of coining terms based on older Icelandic words rather than directly taking in loanwords from other languages. Since the written language has not changed much, Icelandic speakers can read classic ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Hringvegur
Route 1 or the Ring Road ( or ) is a national road in Iceland that circles the entire country. As a major trunk route, it is considered to be the most important piece of transport infrastructure in Iceland as it connects the majority of towns together in the most densely populated areas of the country. Economically, it carries a large proportion of goods traffic as well as tourist traffic. The total length of the road is . The road was completed in 1974, coinciding with the 1,100th anniversary of the country's settlement when the longest bridge in Iceland, crossing the Skeiðará river in the southeast, was opened. Previously, vehicles intending to travel between southern settlements, e.g. Vík to Höfn, had to travel north of the country through Akureyri, making the opening a major transport improvement to the country. Many popular tourist attractions in Iceland, such as the Seljalandsfoss and Skógafoss waterfalls, Dyrhólaey cliffs, Jökulsárlón glacier lagoon, as well ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Skeiðará
Skeiðará () is a relatively short glacier river (about 30 km long). It has its source on the glacier Skeiðarárjökull, one of the southern arms of the Vatnajökull in the south of Iceland. In spite of its short length, this river has a bad reputation. It is especially feared because of the frequent glacier runs that can be fatal. In front of Skaftafell and Skeiðarárjökull, Skeiðará has formed the Skeiðarársandur, a black plain of lava sand and ashes crossed by a lot of small rivulets which covers the whole area between the park and the sea (about 40 km long and 5 to 10 km wide). In 1996, the latest of these glacier runs took place. It destroyed parts of Route 1 (the Ring Road). The bridge was damaged by floating ice boulders the size of houses. At the peak of this glacier run, 45,000 m3/s of water were coming down. No one was harmed, scientists having very carefully monitored the volcano Grímsvötn on Vatnajökull which caused the glacier run by ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
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