Gamburtsev Mountain Range

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Gamburtsev Mountain Range
Highest point
Elevation 3,400 m (11,200 ft)
Coordinates 80°30′S76°00′E / 80.500°S 76.000°E / -80.500; 76.000
Dimensions
Length1,200 km (750 mi)
Geography
ContinentAntarctica
RegionEast Antarctica

The Gamburtsev Mountain Range (also known as the Gamburtsev Subglacial Mountains) is a subglacial mountain range located in East Antarctica, just underneath the lofty Dome A, near the Southern Pole of Inaccessibility. [1] The range was discovered by the 3rd Soviet Antarctic Expedition in 1958 and is named for Soviet geophysicist Grigoriy A. Gamburtsev. [2] [3] It is approximately 1,200 kilometres (750 mi) long, and the mountains are believed to be about 2,700 metres (8,900 ft) high, [4] although they are completely covered by over 600 metres (2,000 ft) of ice and snow. The Gamburtsev Mountain Range is about the same size as the European Alps. [5] As of 2008, it was unknown how the mountains were formed due to the lack of data. Studies conducted during the International Polar year demonstrated that ancient plate collisions produced a core that was rejuvenated in the early to mid-Mesozoic . The main features of the range formed before 34 million years ago, when the area was covered by the present ice sheet. [6] Current models suggest that the East Antarctic ice sheet was formed from the glaciers that began sliding down the Gamburtsev range at the end of the Eocene. [1] Vostok Subglacial Highlands form an east extension of Gamburtsev Subglacial Mountains. [7]

Contents

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Gamburtsev
Gamburtsev Mountain Range in Antarctica

As part of the 2007–09 International Polar Year, so called, the AGAP project was a multinational effort to gather information about the Gamburtsev mountain chain. [8] [9]

Completion

Scientists announced the completion of their mission on 25 February 2009. [5] Modern-day remote-sensing technology revealed a very jagged landscape. [5] The gathered data will be analysed by researchers in the following months. [5] Dr Fausto Ferraccioli from the British Antarctic Survey said: "We can confirm they are there; we've seen them under the ice. Not only are they similar in dimension to the European Alps, but they are also similar in aspect: we see very sharp peaks and valleys which are remarkably similar to the Alps themselves. It all adds to the mystery from the tectonic perspective of how these mountains were created; and from the glacial history perspective of how the East Antarctic ice sheet was formed and didn't erode these peaks." [5]

The AGAP project comprised scientists, engineers, pilots and support staff from Australia, Canada, China, Germany, Japan, the United Kingdom, and the United States. [5] [10] Two field camps were established deep within the Antarctic interior and aircraft flew across the ice, mapping the shape of the sub-glacials using an ice-penetrating radar. [5] The local gravitational and magnetic fields were also measured. [5] 120,000 km were flown, with over 20% of the East Antarctic Ice Sheet being explored during the course of the mission. [5]

Information was recorded on a network of seismometers that picked up earthquake signals passing through the rock from the opposite side of the planet. [5] Despite the extreme temperatures — around −30 °C at the two base camps as reported by AGAP US co-leader Dr Robin Bell — liquid water was detected in the valleys three kilometres beneath the team. [5] Ferraccioli added: "Up until now we just had an ambitious plan. Now we have all this remarkable data to pore over." [5]

By December, 2009, data analyzed so far from the AGAP project indicate the mountain range is generally oriented southwest to northeast, and arose from tectonic plate activity. [11]

The team's next goal is to drill through the ice and collect the first Gamburtsev rock samples. "Amazingly, we have samples of the moon but none of the Gamburtsevs," said Robin Bell, a geophysicist at Columbia University's Lamont–Doherty Earth Observatory. "With these rock samples we will be able to constrain when this ancient piece of crust was rejuvenated and grew to a magnificent mountain range." [12]

Origin

The result of the 2007–2009 study has found that the Gamburtsev are very old, first forming around a billion years ago when continental drift pushed two plates together to form the super-continent of Rodinia. This early range was eroded above the surface but left a deep cold root, which is visible today in seismic images, [13] reaching down into the Earth's mantle. About 250-100 million years ago, the crust started to pull apart in a series of rifting events close to the east of this old root. A forked rift valley runs along the northern side of the mountains containing lakes Sovetskaya and 90East within it. This rifting warmed and rejuvenated the root, giving it the buoyancy to be lifted up to re-establish the mountains as an 800 km long massif. Further uplift still was achieved as deep valleys were later cut erosion lightening the overall mass of the system. Around 35 million years ago, the glaciers merged to form the East Antarctic Ice Sheet, burying the Gamburtsev Range in the process. [14]

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<span class="mw-page-title-main">Geography of Antarctica</span>

The geography of Antarctica is dominated by its south polar location and, thus, by ice. The Antarctic continent, located in the Earth's southern hemisphere, is centered asymmetrically around the South Pole and largely south of the Antarctic Circle. It is washed by the Southern Ocean or, depending on definition, the southern Pacific, Atlantic, and Indian Oceans. It has an area of more than 14.2 million km2. Antarctica is the largest ice desert in the world.

<span class="mw-page-title-main">Lake Vostok</span> Antarcticas largest known subglacial lake

Lake Vostok is the largest of Antarctica's 675 known subglacial lakes. Lake Vostok is located at the southern Pole of Cold, beneath Russia's Vostok Station under the surface of the central East Antarctic Ice Sheet, which is at 3,488 m (11,444 ft) above mean sea level. The surface of this fresh water lake is approximately 4,000 m (13,100 ft) under the surface of the ice, which places it at approximately 500 m (1,600 ft) below sea level.

<span class="mw-page-title-main">Alexander Island</span> Island in the Bellingshausen Sea off Antarctica

Alexander Island, which is also known as Alexander I Island, Alexander I Land, Alexander Land, Alexander I Archipelago, and Zemlja Alexandra I, is the largest island of Antarctica. It lies in the Bellingshausen Sea west of Palmer Land, Antarctic Peninsula from which it is separated by Marguerite Bay and George VI Sound. The George VI Ice Shelf entirely fills George VI Sound and connects Alexander Island to Palmer Land. The island partly surrounds Wilkins Sound, which lies to its west. Alexander Island is about 390 kilometres (240 mi) long in a north–south direction, 80 kilometres (50 mi) wide in the north, and 240 kilometres (150 mi) wide in the south. Alexander Island is the second-largest uninhabited island in the world, after Devon Island.

<span class="mw-page-title-main">Marie Byrd Land</span> Unclaimed West Antarctic region

Marie Byrd Land (MBL) is an unclaimed region of Antarctica. With an area of 1,610,000 km2 (620,000 sq mi), it is the largest unclaimed territory on Earth. It was named after the wife of American naval officer Richard E. Byrd, who explored the region in the early 20th century.

<span class="mw-page-title-main">Gaussberg</span> Volcanic cone in Antarctica

Gaussberg is an extinct, 370-metre-high (1,210-foot) high volcanic cone in East Antarctica fronting on Davis Sea immediately west of Posadowsky Glacier. It is ice-free and conical in nature, having formed subglacially about 55,000 years ago. The current edifice is thought to be the remains of a once-larger mountain that has been reduced by glacial and subaerial erosion. The volcano has produced lamproite magmas, and is the youngest volcano to have produced such magmas on Earth.

<span class="mw-page-title-main">Crary Mountains</span> Volcanoes in Antarctica

Crary Mountains are a group of ice-covered volcanoes in Marie Byrd Land, Antarctica. They consist of two or three shield volcanoes, named Mount Rees, Mount Steere and Mount Frakes, which developed during the course of the Miocene and Pliocene and last erupted about 30,000-40,000 years ago. The first two volcanoes are both heavily incised by cirques, while Mount Frakes is better preserved and has a 4 kilometres (2.5 mi) wide caldera at its summit. Boyd Ridge is another part of the mountain range and lies southeast of Mount Frakes; it might be the emergent part of a platform that underlies the mountain range.

<span class="mw-page-title-main">Subglacial lake</span> Lake under a glacier

A subglacial lake is a lake that is found under a glacier, typically beneath an ice cap or ice sheet. Subglacial lakes form at the boundary between ice and the underlying bedrock, where gravitational pressure decreases the pressure melting point of ice. Over time, the overlying ice gradually melts at a rate of a few millimeters per year. Meltwater flows from regions of high to low hydraulic pressure under the ice and pools, creating a body of liquid water that can be isolated from the external environment for millions of years.

<span class="mw-page-title-main">Denman Glacier</span> Glacier in Queen Mary Land, Antarctica

Denman Glacier is a glacier 11 to 16 km wide, descending north some 110 km (70 mi), which debouches into the Shackleton Ice Shelf east of David Island, Queen Mary Land. It was discovered in November 1912 by the Western Base party of the Australasian Antarctic Expedition under Sir Douglas Mawson. Mawson named the glacier for Lord Denman, Governor-General of Australia in 1911, a patron of the expedition.

<span class="mw-page-title-main">East Antarctica</span> Part of Antarctica that lies within the Eastern Hemisphere

East Antarctica, also called Greater Antarctica, constitutes the majority (two-thirds) of the Antarctic continent, lying primarily in the Eastern Hemisphere south of the Indian Ocean, and separated from West Antarctica by the Transantarctic Mountains. It is generally greater in elevation than West Antarctica, and includes the Gamburtsev Mountain Range in the center. The geographic South Pole is located within East Antarctica.

<span class="mw-page-title-main">West Antarctic Rift System</span> Series of rift valleys between East and West Antarctica

The West Antarctic Rift System is a series of rift valleys between East and West Antarctica. It encompasses the Ross Embayment, the Ross Sea, the area under the Ross Ice Shelf and a part of Marie Byrd Land in West Antarctica, reaching to the base of the Antarctic Peninsula. It has an estimated length of 3,000 km (1,900 mi) and a width of approximately 700 km (430 mi). Its evolution is due to lithospheric thinning of an area of Antarctica that resulted in the demarcation of East and West Antarctica. The scale and evolution of the rift system has been compared to that of the Basin and Range Province of the Western United States.

<span class="mw-page-title-main">East Antarctic Ice Sheet</span> Segment of the continental ice sheet that covers East Antarctica

The East Antarctic Ice Sheet (EAIS) lies between 45° west and 168° east longitudinally. It was first formed around 34 million years ago, and it is the largest ice sheet on the entire planet, with far greater volume than the Greenland ice sheet or the West Antarctic Ice Sheet (WAIS), from which it is separated by the Transantarctic Mountains. The ice sheet is around 2.2 km (1.4 mi) thick on average and is 4,897 m (16,066 ft) at its thickest point. It is also home to the geographic South Pole, South Magnetic Pole and the Amundsen–Scott South Pole Station.

<span class="mw-page-title-main">Rutford Ice Stream</span> Antarctic ice stream

Rutford Ice Stream is a major Antarctic ice stream, about 290 kilometres (180 mi) long and over 24 kilometres (15 mi) wide, which drains southeastward between the Sentinel Range, Ellsworth Mountains and Fletcher Ice Rise into the southwest part of Ronne Ice Shelf. Named by US-ACAN for geologist Robert Hoxie Rutford, a member of several USARP expeditions to Antarctica; leader of the University of Minnesota Ellsworth Mountains Party, 1963-1964. Rutford served as Director of the Division of Polar Programs, National Science Foundation, 1975-1977.

<span class="mw-page-title-main">Tectonic evolution of the Transantarctic Mountains</span>

The tectonic evolution of the Transantarctic Mountains appears to have begun when Antarctica broke away from Australia during the late Cretaceous and is ongoing, creating along the way some of the longest mountain ranges formed by rift flank uplift and associated continental rifting. The Transantarctic Mountains (TAM) separate East and West Antarctica. The rift system that formed them is caused by a reactivation of crust along the East Antarctic Craton. This rifting or seafloor spreading causes plate movement that results in a nearby convergent boundary which then forms the mountain range. The exact processes responsible for making the Transantarctic Mountains are still debated today. This results in a large variety of proposed theories that attempt to decipher the tectonic history of these mountains.

<span class="mw-page-title-main">East Antarctic Shield</span> Cratonic rock body which makes up most of the continent Antarctica

The East Antarctic Shield or Craton is a cratonic rock body that covers 10.2 million square kilometers or roughly 73% of the continent of Antarctica. The shield is almost entirely buried by the East Antarctic Ice Sheet that has an average thickness of 2200 meters but reaches up to 4700 meters in some locations. East Antarctica is separated from West Antarctica by the 100–300 kilometer wide Transantarctic Mountains, which span nearly 3,500 kilometers from the Weddell Sea to the Ross Sea. The East Antarctic Shield is then divided into an extensive central craton that occupies most of the continental interior and various other marginal cratons that are exposed along the coast.

Helen Amanda Fricker is a glaciologist and professor at Scripps Institution of Oceanography at the University of California, San Diego where she is a director of the Scripps Polar Center. She won the 2010 Martha T. Muse Prize for Science and Policy in Antarctica.

<span class="mw-page-title-main">Terry Wilson (scientist)</span> International leader in the study of present-day tectonics in Antarctica

Terry Jean Wilson is an international leader in the study of present-day tectonics in Antarctica. She has led large, international efforts, such as Polar Earth Observing Network (POLENET), to investigate the interactions between the Earth's crust and the cryosphere in Antarctica.

<span class="mw-page-title-main">Robin Bell (scientist)</span> American geophysicist

Robin Elizabeth Bell is Palisades Geophysical Institute (PGI) Lamont Research Professor at Columbia University's Lamont–Doherty Earth Observatory and a past President of the American Geophysical Union (AGU), 2019–2021. Dr. Bell was influential in co-ordinating the 2007 International Polar Year and was the first woman to chair the National Academy of Sciences Polar Research Board. She has made numerous important discoveries with regard to subglacial lakes and ice sheet dynamics, and has a ridge, called Bell Buttress, in Antarctica named after her.

<span class="mw-page-title-main">Bruce P. Luyendyk</span> American geophysicist and oceanographer (born 1943)

Bruce Peter Luyendyk is an American geophysicist and oceanographer, currently professor emeritus of marine geophysics at the University of California, Santa Barbara. His work spans marine geology of the major ocean basins, the tectonics of southern California, marine hydrocarbon seeps, and the tectonics and paleoclimate of Antarctica. His research includes tectonic rotations of the California Transverse Ranges, participation in the discovery of deep-sea hydrothermal vents, quantitative studies of marine hydrocarbon seeps, and geologic exploration of the Ford Ranges in Marie Byrd Land, Antarctica.

Kirsteen Jane Tinto is a glaciologist known for her research on the behavior and subglacial geology of the Greenland and Antarctic ice sheets.

<span class="mw-page-title-main">Keilir (mountain)</span>

Keilir is a Pleistocene subglacial mound or perhaps a conical tuya on Reykjanes Peninsula in Iceland. Basal area is 0.773 km2, summit area 0.004 km2, basal width 0.99 km, summit width 0.07 km, volume 0.0362 km3.

References

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  3. "20 лет открытию Полюса недоступности Антарктиды: Метеорология и Гидрология. 1979, №3. Гидрометеоиздат" (in Russian). Arctic and Antarctic Research Institute. Archived from the original on 2007-03-10. Retrieved 2007-01-26.
  4. Robin E Bell (2008-11-12). "Dispatches from the Bottom of the Earth: An Antarctic Expedition in Search of Large Mountains Encased in Ice". Scientific American. Retrieved 2008-11-12.
  5. 1 2 3 4 5 6 7 8 9 10 11 12 "'Ghost peaks' emerge from the ice". BBC. 2009-02-25. Retrieved 2009-02-25.
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  7. Vostok Subglacial Highlands: Antarctica geographic.org
  8. Bryan C. Storey (2006-03-23). "The Gamburtsev Mountains: Integrated International Exploration of the Earths Most Enigmatic Mountain Range". International Polar Year. Archived from the original on 2006-08-19.
  9. Jonathan Amos (2008-10-14). "Expedition set for 'ghost peaks'". BBC News.
  10. "U.S.-led, International Research Team Confirms Alps-like Mountain Range Exists under East Antarctic Ice Sheet" (Press release). National Science Foundation. 24 February 2009. Retrieved 11 Jan 2010.
  11. Jonathan Amos (2009-12-18). "Data to expose 'ghost mountains'". BBC . Retrieved 2009-12-18.
  12. "Researchers Unravel Origins of Antarctica's Ice-Covered Mountains – the Earth Institute – Columbia University".
  13. Heeszel, D.; Wiens, D.; Nyblade, A.; Hansen4, S.; Kanao, M.; An, M.; Zhao, Y. (2013). "Rayleigh wave constraints on the structure and tectonic history of the Gamburtsev Subglacial Mountains, East Antarctica". Journal of Geophysical Research: Solid Earth. 118 (5). J. Geophys. Res., 118, 1–16, doi:doi:10.1002/jgrb.50171: 2138–2153. Bibcode:2013JGRB..118.2138H. doi: 10.1002/jgrb.50171 .{{cite journal}}: CS1 maint: numeric names: authors list (link)
  14. Amos, Jonathan (17 November 2011). "Gamburtsev 'ghost mountains mystery solved'". BBC News. Retrieved 17 November 2011.