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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 pl ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Glaciofluvial Deposits
Fluvioglacial landforms or glaciofluvial landforms are those that result from the associated erosion and deposition of sediments caused by glacial meltwater. Glaciers contain suspended sediment loads, much of which is initially picked up from the underlying landmass. Landforms are shaped by glacial erosion through processes such as glacial quarrying, abrasion, and meltwater. Glacial meltwater contributes to the erosion of bedrock through both mechanical and chemical processes.Glasser, N. F. & Bennett, M. R. Glacial erosional landforms: Origins and significance for palaeoglaciology. ''Prog. Phys. Geogr.'' 28, 43–75 (2004). Fluvio-glacial processes can occur on the surface and within the glacier. The deposits that happen within the glacier are revealed after the entire glacier melts or partially retreats. Fluvio-glacial landforms and erosional surfaces include: outwash plains, kames, kame terraces, kettle holes, eskers, varves, and proglacial lakes. Meltwater streams and fo ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Kettle Lake
A kettle (also known as a kettle hole, kettlehole, or pothole) is a depression or 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 and 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 acidic conditions, a kettle bog may form but in alkaline conditions, it will be kettle peatland. Overview Kettles ar ... [...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 to 30 km. The Skeiðará was the most important obstacle in the construction of Iceland's Route 1 (Iceland), 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 jökulhlaup, 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 accumula ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Braided Stream
A braided river (also called braided channel or braided stream) consists of a network of river channels separated by small, often temporary, islands called '' braid bars'' or, in British English usage, '' aits'' or ''eyots''. Braided streams tend to occur in rivers with high sediment loads or coarse grain sizes, and in rivers with steeper slopes than typical rivers with straight or meandering channel patterns. They are also associated with rivers with rapid and frequent variation in the amount of water they carry, i.e., with " flashy" rivers, and with rivers with weak banks. Braided channels are found in a variety of environments all over the world, including gravelly mountain streams, sand bed rivers, on alluvial fans, on river deltas, and across depositional plains. Description A braided river consists of a network of multiple shallow channels that diverge and rejoin around ephemeral ''braid bars''. This gives the river a fancied resemblance to the interwoven strands of a ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Glacier
A glacier (; or ) is a persistent body of dense ice, a form of rock, that is constantly moving downhill under its own weight. A glacier forms where the accumulation of snow exceeds its ablation over many years, often centuries. It acquires distinguishing features, such as crevasses and 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“Glacier, N., Pronunciation.” Oxford English Dictionary, Oxford UP, June 2024, https://doi.org/10.1093/OED/7553486115. Accessed 25 Jan. 2025. 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 ever ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Gaspé Peninsula
The Gaspé Peninsula, also known as Gaspesia (, ; ), is a peninsula along the south shore of the St. Lawrence River that extends from the Matapedia Valley in Quebec, Canada, into the Gulf of St. Lawrence. It is separated from New Brunswick on its southern side by baie des Chaleurs, Chaleur Bay and the Restigouche River. The name ''Gaspé'' comes from the Mi'kmaq word , meaning "end", referring to the end of the land. The Gaspé Peninsula is slightly larger than Belgium, at . The population is 140,599 as of the 2011 Canadian census, 2011 census.The population of the Gaspe Peninsula is determined by adding the population of two federal electoral districts, Haute-Gaspésie—La Mitis—Matane—Matapédia and Gaspésie—Les Îles-de-la-Madeleine, Gaspésie—Îles-de-la-Madeleine, while subtracting that of the Magdalen Islands. It is also noted as the only region outside the Channel Islands to contain native speakers of Jèrriais, Jersey Norman. Geography Sea cliffs dominate the p ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Quebec
Quebec is Canada's List of Canadian provinces and territories by area, largest province by area. Located in Central Canada, the province shares borders with the provinces of Ontario to the west, Newfoundland and Labrador to the northeast, New Brunswick to the southeast and a coastal border with the territory of Nunavut. In the south, it shares a border with the United States. Between 1534 and 1763, what is now Quebec was the List of French possessions and colonies, French colony of ''Canada (New France), Canada'' and was the most developed colony in New France. Following the Seven Years' War, ''Canada'' became a Territorial evolution of the British Empire#List of territories that were once a part of the British Empire, British colony, first as the Province of Quebec (1763–1791), Province of Quebec (1763–1791), then Lower Canada (1791–1841), and lastly part of the Province of Canada (1841–1867) as a result of the Lower Canada Rebellion. It was Canadian Confederation, ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Pleistocene
The Pleistocene ( ; referred to colloquially as the ''ice age, Ice Age'') is the geological epoch (geology), epoch that lasted from to 11,700 years ago, spanning the Earth's most recent period of repeated glaciations. Before a change was finally confirmed in 2009 by the International Union of Geological Sciences, the cutoff of the Pleistocene and the preceding Pliocene was regarded as being 1.806 million years Before Present (BP). Publications from earlier years may use either definition of the period. The end of the Pleistocene corresponds with the end of the last glacial period and also with the end of the Paleolithic age used in archaeology. The name is a combination of Ancient Greek () 'most' and (; Latinized as ) 'new'. The aridification and cooling trends of the preceding Neogene were continued in the Pleistocene. The climate was strongly variable depending on the glacial cycle, oscillating between cold Glacial period, glacial periods and warmer Interglacial, int ... [...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 10% of the country. Size With an area of 7,700 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. Peaks Hrútsfjallstindar is a series of Icelandic peaks rising from Vatnajökull between Svínafellsjök ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Volcano
A volcano is commonly defined as a vent or fissure in the crust of a planetary-mass object, such as Earth, that allows hot lava, volcanic ash, and gases to escape from a magma chamber below the surface. On Earth, volcanoes are most often found where tectonic plates are diverging or converging, and because most of Earth's plate boundaries are underwater, most volcanoes are found underwater. For example, a mid-ocean ridge, such as the Mid-Atlantic Ridge, has volcanoes caused by divergent tectonic plates whereas the Pacific Ring of Fire has volcanoes caused by convergent tectonic plates. Volcanoes resulting from divergent tectonic activity are usually non-explosive whereas those resulting from convergent tectonic activity cause violent eruptions."Mid-ocean ridge tectonics, volcanism and geomorphology." Geology 26, no. 455 (2001): 458. https://macdonald.faculty.geol.ucsb.edu/papers/Macdonald%20Mid-Ocean%20Ridge%20Tectonics.pdf Volcanoes can also form where there is str ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
