Subglacial volcano

A subglacial volcano, also known as a glaciovolcano, is a volcanic form produced by subglacial eruptions or eruptions beneath the surface of a glacier or ice sheet which is then melted into a lake by the rising lava. Today they are most common in Iceland and Antarctica; older formations of this type are found also in British Columbia and Yukon Territory, Canada.

During the eruption, the heat of the lava from the subglacial volcano melts the overlying ice. The water quickly cools the lava, resulting in pillow lava shapes similar to those of underwater volcanoes. When the pillow lavas break off and roll down the volcano slopes, pillow breccia, tuff breccia, and hyaloclastite form. The meltwater may be released from below the ice as happened in Iceland in 1996 when the Grímsvötn caldera erupted, melting 3 km3 of ice and giving rise to a large glacial lake outburst flood.

The shape of subglacial volcanoes tends to be quite characteristic and unusual, with a flattened top and steep sides supported against collapse by the pressure of the surrounding ice and meltwater. If the volcano eventually melts completely through the ice layer, then horizontal lava flows are deposited, and the top of the volcano assumes a nearly level form. However, if significant amounts of lava are later erupted subaerially, then the volcano may assume a more conventional shape. In Canada the volcanos have been known to form both conical and nearly level shapes.[1] The more distinctly flat-topped, steep-sided subglacial volcanoes are called tuyas, named after Tuya Butte in northern British Columbia by Canadian geologist Bill Mathews in 1947. In Iceland, such volcanoes are also known as table mountains.

Subglacial Eruption-numbers
Scheme of subglacial volcano eruption

Jökulhlaups

Subglacial eruptions often cause jökulhlaups or great floods of water. In November 1996 the Grímsvötn Volcano beneath the Vatnajökull ice sheet erupted and caused a Jökulhlaup that affected more than 750 km2 (290 sq mi) and destroyed or severely damaged several bridges.[2] During the ice ages, such floods from Lake Missoula were estimated to have discharges exceeding 17 × 106 m³/s (4.5 × 109 gal/s) and covered a third of eastern Washington state. Sonia Esperanca, program director in the National Science Foundation commented on the danger of subglacial volcanoes: "When an ice-covered volcano erupts, the interplay among molten magma, ice and meltwater can have catastrophic results."[3]

Antarctica eruption

In January, 2008, the British Antarctic Survey (Bas) scientists led by Hugh Corr and David Vaughan, reported (in the journal Nature Geoscience) that 2,200 years ago, a volcano erupted under the Antarctica ice sheet (based on airborne survey with radar images). The biggest eruption in the last 10,000 years, the volcanic ash was found deposited on the ice surface under the Hudson Mountains, close to Pine Island Glacier.[4]

On Mars

Many scientists believe that liquid water exists many kilometers below the surface of Mars, but at this point in time it is impossible to drill to those depths with the rovers in existence. Meredith Payne and Jack Farmer of Arizona State University have studied images from the Viking and Mars Orbiter cameras in search of possible sub-glacial volcanoes that could carry microbes to the surface.[5]

Ice cores

It is possible to track catastrophic subglacial volcano eruptions in time with the analysis of ice cores such as the Vostok core. Subglacial volcanic eruptions are identified by layers of high concentrations of NO
3
and SO2−
4
.[6]

See also

References

  1. ^ "Volcanoes of Canada". Geological Survey of Canada. Archived from the original on February 2, 2009. Retrieved January 19, 2009.
  2. ^ http://www.accessscience.com/content.aspx?searchStr=subglacial+volcano&id=735200
  3. ^ "Volcanoes Under Glaciers in Iceland, Canada and the United States". Archived from the original on May 4, 2010. Retrieved June 1, 2010.
  4. ^ Black, Richard (20 January 2008). "Ancient Antarctic eruption noted". BBC News. London: BBC. Archived from the original on 15 January 2009. Retrieved 22 October 2011.
  5. ^ "Subglacial Volcanoes On Mars". Archived from the original on 2011-06-06.
  6. ^ "International Glaciological Society" (PDF). International Glaciological Society (IGS). Archived (PDF) from the original on 2018-05-04.
David Vaughan (glaciologist)

David Glyn Vaughan OBE (born RAF Akrotiri 23 October 1962) is a climate scientist at the British Antarctic Survey. His research focus is the role of ice sheets in the Earth system and the societal threat of climate change and rising sea levels. He is a co-ordinating Lead Author of the IPCC Fourth Assessment Report. His research work includes the mapping of the bed under Pine Island Glacier and the discovery of a subglacial volcano.Vaughan graduated from Churchill College, Cambridge with a degree in Natural Sciences in 1984. He then earned a MSc in Geophysics from Durham University (Hatfield College) in 1985, after which he joined the British Antarctic Survey, taking part in multiple field campaigns over the following years. He gained his PhD from the Open University in 1995. He was appointed Officer of the Order of the British Empire (OBE) in the 2017 New Year Honours for services to glaciology.

Fiftytwo Ridge

Fiftytwo Ridge is a mountain ridge in east-central British Columbia, Canada, located just southwest of Battle Mountain at the southeastern end of Wells Gray Provincial Park.

Hayrick Butte

Hayrick Butte is a tuya, a type of subglacial volcano, in Linn County, Oregon. Located in the Willamette National Forest near Santiam Pass, it lies adjacent to the cinder cone Hoodoo Butte, which has a ski area. Hayrick Butte likely formed when lava erupted underneath an overlying glacier or ice sheet, producing the flat top with near-vertical walls along the ice-contact margin as the lava cooled and hardened. Hayrick Butte has a nearly flat plateau about 0.5 miles (0.80 km) across and steep walls rising about 700 feet (0.21 km) above its surroundings. A cartographer accidentally switched the names for nearby Hoodoo Butte and Hayrick Butte; the word "hoodoo" usually refers to rock piles and pinnacles like those observed at Hayrick Butte.

Compared to Hoodoo, Hayrick is less popular for recreation, though it can be climbed, and there are hiking, snowshoeing, and snowmobile routes surrounding the butte. Its north-facing slope has subalpine forests with mountain hemlock and fir, which are common in the Cascades.

Hofsjökull

Hofsjökull (Icelandic: “temple glacier”) is the third largest glacier in Iceland after Vatnajökull and Langjökull and the largest active volcano in the country. It is situated in the west of the Highlands of Iceland and north of the mountain range Kerlingarfjöll, between the two largest glaciers of Iceland. It covers an area of 925 km2, reaching 1,765 m (5,791 ft) at its summit. The subglacial volcano is a shield type with caldera.Hofsjökull is the source of several rivers including the Þjórsá, Iceland's longest river.In the southeast of Iceland, between the easternmost glacier tongue of Vatnajökull (Axajökull) and Þrándarjökull, is a smaller glacier (area about 4 km²), which is also called Hofsjökull.In 2015, Hofsjökull increased in mass, the first time in 20 years this had happened.

Hogg Rock

Hogg Rock is a tuya volcano and lava dome in the Cascade Range of northern Oregon, located close to Santiam Pass. Produced by magma with an intermediate andesite composition, it has steep slopes and thick glassy margins. Hogg Rock exhibits normal magnetic polarity and is probably about 80,000 years old.

Hogg Rock lies south of Three Fingered Jack and north of Hayrick Butte, a somewhat larger tuya of similar age and composition. A tuya is a type of subglacial volcano, formed when lava erupts underneath an overlying glacier or ice sheet and then melts through to the surface and pools, producing the flat plateau on top with near-vertical walls along the ice-contact margin as the lava cools and hardens. It is a historic landmark, with the remnants of Colonel T. Egenton Hogg's Oregon Pacific Railroad, the Santiam Lodge, and a quarry. The mountain offers snowshoe and snowmobile trails, and its summit provides views of the surrounding area including volcanoes like the Black Butte stratovolcano, Mount Washington, Sand Mountain, and Potato Hill.

Jack's Jump

Jack's Jump is a subglacial volcano in east-central British Columbia, Canada, located in south-central Wells Gray Provincial Park.

Loki-Fögrufjöll

Loki-Fögrufjöll (also known as Hamarinn or Lokahryggur) is a subglacial volcano under the Vatnajökull glacier.

The subglacial volcano is found within the Bárðarbunga fissure system, but is independent of Bárðarbunga itself.

The last confirmed eruption was in 1910 when Tephra was erupted, but may also have had subglacial eruptions in, 1986, 1991, 2006 and 2008.

Meehaz Mountain

Meehaz Mountain is a mountain in the Cassiar Country of the Northern Interior of British Columbia, Canada, located on the north side of the headwaters of Teslin River and to the south of the Atsutla Range. It is a product of subglacial volcanism during the Pleistocene period when this area was covered by thick glacial ice, forming a subglacial volcano that never broke through the overlying glacial ice known as a subglacial mound.

Nuthinaw Mountain

Nuthinaw Mountain is a mountain on the Stikine Plateau in northern British Columbia, Canada, located east of Tutsingale Mountain and 72 km (45 mi) northwest of Dease Lake on the north side of Tachilta Lakes. It is a product of subglacial volcanism during the Pleistocene period when this area was covered by thick glacial ice, forming a subglacial volcano that never broke through the overlying glacial ice known as a subglacial mound.

Nuthinaw is a Tahltan name meaning Cariboo fence went right into mountain.

Pali Dome

Pali Dome is a subglacial volcano in the Pacific Ranges of the Coast Mountains in southwestern British Columbia, Canada. It is part of the Mount Cayley volcanic field and its elevation is 2,250 m (7,380 ft). For the past 2 million years, the Mount Cayley volcanic field has had interactions between ice and lava which have created some unique landforms and an in-ice drainage system."Pali" comes from the Hawaiian word that means cliff or steep hill, while dome refers to the lava dome, which is when doughy lava flows from a volcanic vent which is usually rounded and flat on top.One of the last known eruptions of the Pali Dome was over 10,000 years ago.

Pillow Creek

Pillow Creek is a creek in east-central British Columbia, Canada, located in the northeast corner of Wells Gray Provincial Park.

Pillow Creek is home to a subglacial volcano that formed and last erupted during the Pleistocene period.

Pine Island Glacier

Pine Island Glacier (PIG) is a large ice stream, and the fastest melting glacier in Antarctica, responsible for about 25% of Antarctica's ice loss. The glacier ice streams flow west-northwest along the south side of the Hudson Mountains into Pine Island Bay, Amundsen Sea, Antarctica. It was mapped by the United States Geological Survey (USGS) from surveys and United States Navy (USN) air photos, 1960–66, and named by the Advisory Committee on Antarctic Names (US-ACAN) in association with Pine Island Bay.The area drained by Pine Island Glacier comprises about 10% of the West Antarctic Ice Sheet. Satellite measurements have shown that the Pine Island Glacier Basin has a greater net contribution of ice to the sea than any other ice drainage basin in the world and this has increased due to recent acceleration of the ice stream.The ice stream is extremely remote, with the nearest continually occupied research station at Rothera, nearly 1,300 km (810 mi) away. The area is not claimed by any nations and the Antarctic Treaty prohibits any new claims while it is in force.

Slag Hill

Slag Hill is a subglacial volcano associated with the Mount Cayley volcanic field in British Columbia, Canada. It consists of glassy, augite-phyric basaltic andesite in steep-sided, glassy, finely jointed domes and one small, flat-topped bluff. The finely jointed domes are similar to those of Ember Ridge. There are quench features at Slag Hill, which is suggesting that the volcanic activity was subglacial. Slag Hill was formed throughout the Pleistocene period, but its most recent volcanic activity produced a lava flow on its western lobe that shows no evidence of ice-contact volcanism. This indicates the lava flow was erupted less than 10,000 years ago after the last glacial period.

Subglacial mound

A subglacial mound (SUGM) is a type of subglacial volcano. This type of volcano forms when lava erupts beneath a thick glacier or ice sheet. The magma forming these volcanoes was not hot enough to melt a vertical pipe right through the overlying glacial ice, instead forming hyaloclastite and pillow lava deep beneath the glacial ice field. Once the glaciers had retreated, the subglacial volcano would be revealed, with a unique shape as a result of their confinement within glacial ice. They are somewhat rare worldwide, being confined to regions which were formerly covered by continental ice sheets and also had active volcanism during the same period. They are found throughout Iceland, Antarctica and the Canadian province of British Columbia.

Subglacial mounds can be mistaken for cinder cones because they may have a similar shape. An example of this confusion is Pyramid Mountain in the Wells Gray-Clearwater volcanic field of east-central British Columbia, Canada.

Tutsingale Mountain

Tutsingle Mountain is a mountain on the Stikine Plateau in northern British Columbia, Canada, located east of Nuthinaw Mountain and northwest of Dease Lake on the northeast side of the Tachilta Lakes. It is a product of subglacial volcanism during the Pleistocene period when this area was covered by thick glacial ice, forming a subglacial volcano that never broke through the overlying glacial ice known as a subglacial mound.

Underwater volcano

Underwater volcano may refer to:

Subaqueous volcano, a volcano that forms under a lake

Submarine volcano, a volcano that forms under an ocean

Viedma (disambiguation)

Viedma is the capital of Río Negro province, Argentina.

Viedma may also refer to:

Viedma Department, a part of Chubut province, ArgentinaGeographic featuresViedma Lake, a lake in southern Patagonia

Viedma Glacier, a large glacier in southern Patagonia

Viedma (volcano), a subglacial volcano in southern PatagoniaPeopleJuan Viedma (footballer), a retired Spanish-Dutch footballer

Juan Viedma (athlete), a paralympic athlete from Spain

Viedma (volcano)

Viedma (Spanish pronunciation: [ˈbjeðma]) is a subglacial volcano located below the ice of the Southern Patagonian Ice Field, an area disputed between Argentina and Chile. The 1988 eruption deposited ash and pumice on the ice field and produced a mudflow that reached Viedma Lake. The exact position of the edifice is unclear, both owing to the ice cover and because the candidate position, the "Viedma Nunatak", does not clearly appear to be of volcanic nature. Numerous ash layers in the Viedma lake indicate numerous past eruptions.

Wells Gray-Clearwater volcanic field

The Wells Gray-Clearwater volcanic field, also called the Clearwater Cone Group, is a potentially active monogenetic volcanic field in east-central British Columbia, Canada, located approximately 130 km (81 mi) north of Kamloops. It is situated in the Cariboo Mountains of the Columbia Mountains and on the Quesnel and Shuswap Highlands. As a monogenetic volcanic field, it is a place with numerous small basaltic volcanoes and extensive lava flows.Most of the Wells Gray-Clearwater volcanic field is encompassed within a large wilderness park called Wells Gray Provincial Park. This 5,405 km2 (2,087 sq mi) park was established in 1939 to protect Helmcken Falls and the unique features of the Clearwater River drainage basin, including this volcanic field. Five roads enter the park and provide views of some of the field's volcanic features. Short hikes lead to several other volcanic features, but some areas are accessible only by aircraft.

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