The Transantarctic Mountains (abbreviated TAM) comprise a

mountain range A mountain range or hill range is a series of mountains or hills arranged in a line and connected by high ground. A mountain system or mountain belt is a group of mountain ranges with similarity in form, structure, and alignment that have aris ...

of uplifted rock (primarily sedimentary) in

Antarctica Antarctica () is Earth's southernmost and least-populated continent. Situated almost entirely south of the Antarctic Circle and surrounded by the Southern Ocean (also known as the Antarctic Ocean), it contains the geographic South Pole. ...

which extends, with some interruptions, across the continent from Cape Adare in northern Victoria Land to Coats Land. These mountains divide East Antarctica and West Antarctica. They include a number of separately named mountain groups, which are often again subdivided into smaller ranges. The range was first sighted by

James Clark Ross Sir James Clark Ross (15 April 1800 – 3 April 1862) was a British Royal Navy officer and explorer of both the northern and southern polar regions. In the Arctic, he participated in two expeditions led by his uncle, Sir John Ross, John ...

in 1841 at what was later named the Ross Ice Shelf in his honour. It was first crossed during the

British National Antarctic Expedition The ''Discovery'' Expedition of 1901–1904, known officially as the British National Antarctic Expedition, was the first official British exploration of the Antarctic regions since the voyage of James Clark Ross sixty years earlier (1839–1 ...

of 1901-1904.

Geography

The mountain range stretches between the Ross Sea and the

Weddell Sea The Weddell Sea is part of the Southern Ocean and contains the Weddell Gyre. Its land boundaries are defined by the bay formed from the coasts of Coats Land and the Antarctic Peninsula. The easternmost point is Cape Norvegia at Princess Martha C ...

, the entire width of Antarctica, hence the name. With a total length of about , the Transantarctic Mountains are one of the longest mountain ranges on Earth. The Antarctandes are even longer, having in common with the Transantarctic Mountains the ranges from Cape Adare to the Queen Maud Mountains, but extending thence through the Whitmore Mountains and Ellsworth Mountains up the

Antarctic Peninsula The Antarctic Peninsula, known as O'Higgins Land in Chile and Tierra de San Martin in Argentina, and originally as Graham Land in the United Kingdom and the Palmer Peninsula in the United States, is the northernmost part of mainland Antarctica. ...

. The wide range forms the boundary between East Antarctica and West Antarctica. The East Antarctic Ice Sheet bounds the TAM along their entire length on the Eastern Hemisphere side, while the Western Hemisphere side of the range is bounded by the Ross Sea in Victoria Land from Cape Adare to McMurdo Sound, the Ross Ice Shelf from McMurdo Sound to near the Scott Glacier, and the West Antarctic Ice Sheet beyond. The large summits and dry valleys of the TAM are some of the few places in Antarctica not covered by ice, the highest of which rise more than above sea level. The McMurdo Dry Valleys lie near McMurdo Sound and represent a special Antarctic phenomenon: landscapes that are snow and ice-free due to the extremely limited precipitation and ablation of ice in the valleys. The highest mountain of the TAM is the high Mount Kirkpatrick in the Queen Alexandra Range.

Biology

Penguins, seals, and sea birds live along the Ross Sea coastline in Victoria Land, while life in the interior of the Transantarctic Range is limited to bacteria,

lichen A lichen ( , ) is a hybrid colony (biology), colony of algae or cyanobacteria living symbiotically among hypha, filaments of multiple fungus species, along with yeasts and bacteria embedded in the cortex or "skin", in a mutualism (biology), m ...

algae Algae ( , ; : alga ) is an informal term for any organisms of a large and diverse group of photosynthesis, photosynthetic organisms that are not plants, and includes species from multiple distinct clades. Such organisms range from unicellular ...

, and fungi. Forests once covered Antarctica, including plentiful Wollemi pines and southern beeches.Woodford, J. 2000. The Wollemi Pine. Melbourne: Text Publishing. pp. 85-104 However, with the gradual cooling associated with the break-up of Gondwana, these forests gradually disappeared. It is believed that the last trees on the Antarctic continent were on Transantarctic Mountains.

History

The Transantarctic Mountains were first seen by Captain James Clark Ross in 1841 from the Ross Sea. The range is a natural barrier that must be crossed to reach the

South Pole The South Pole, also known as the Geographic South Pole or Terrestrial South Pole, is the point in the Southern Hemisphere where the Earth's rotation, Earth's axis of rotation meets its surface. It is called the True South Pole to distinguish ...

from the Ross Ice Shelf. The first crossing of the Transantarctic Mountains took place during the 1902–1904

at the Ross Ice Shelf. A reconnaissance party under the command of Albert Armitage reached altitude in 1902. The following year, a party under expedition leader

Robert Falcon Scott Captain Robert Falcon Scott (6 June 1868 – ) was a British Royal Navy officer and explorer who led two expeditions to the Antarctic regions: the Discovery Expedition, ''Discovery'' expedition of 1901–04 and the Terra Nova Expedition ...

crossed into East Antarctica at a location now known as Ferrar Glacier, named after the geologist of the expedition. They explored part of Victoria Land on the Antarctic Plateau before returning via the same glacier. In 1908,

Ernest Shackleton Sir Ernest Henry Shackleton (15 February 1874 – 5 January 1922) was an Anglo-Irish Antarctic explorer who led three British expeditions to the Antarctic. He was one of the principal figures of the period known as the Heroic Age of Antarcti ...

's party crossed the mountains through the Beardmore Glacier. Scott returned to that same glacier in 1911, while

Roald Amundsen Roald Engelbregt Gravning Amundsen (, ; ; 16 July 1872 – ) was a Norwegians, Norwegian explorer of polar regions. He was a key figure of the period known as the Heroic Age of Antarctic Exploration. Born in Borge, Østfold, Norway, Am ...

crossed the range via the Axel Heiberg Glacier. Much of the range remained unexplored until the late 1940s and 1950s, when missions such as Operation Highjump and the

International Geophysical Year The International Geophysical Year (IGY; ), also referred to as the third International Polar Year, was an international scientific project that lasted from 1 July 1957 to 31 December 1958. It marked the end of a long period during the Cold War w ...

(IGY) made extensive use of

aerial photography Aerial photography (or airborne imagery) is the taking of photographs from an aircraft or other flight, airborne platforms. When taking motion pictures, it is also known as aerial videography. Platforms for aerial photography include fixed-wi ...

and concentrated on a thorough investigation of the entire continent. The name "Transantarctic Mountains" was first applied to this range in a 1960 paper by geologist Warren B. Hamilton, following his IGY fieldwork. It was subsequently recommended by the

Advisory Committee on Antarctic Names The Advisory Committee on Antarctic Names (ACAN or US-ACAN) is an advisory committee of the United States Board on Geographic Names responsible for recommending commemorative names for features in Antarctica. History The committee was established ...

, a US authority on geographic names, in 1962. This purely descriptive label (in contrast to many other geographic names on Antarctica) is internationally accepted at present. The Leverett Glacier in the

Queen Maud Mountains The Queen Maud Mountains () are a major group of mountains, ranges and subordinate features of the Transantarctic Mountains, lying between the Beardmore Glacier, Beardmore and Reedy Glaciers and including the area from the head of the Ross Ice Sh ...

is the planned route through the TAM for the overland supply road between McMurdo Station and Amundsen–Scott South Pole Station.

Geology

The Transantarctic Mountains are considerably older than other mountain ranges of the continent, which are mainly volcanic in origin. The range was uplifted during the opening of the West Antarctic Rift System to the east, beginning about 65 million years ago in the early Cenozoic, and soon after became occupied by glaciers. The mountains consist of sedimentary layers lying upon a basement of

granite Granite ( ) is a coarse-grained (phanerite, phaneritic) intrusive rock, intrusive igneous rock composed mostly of quartz, alkali feldspar, and plagioclase. It forms from magma with a high content of silica and alkali metal oxides that slowly coo ...

s and gneisses. The sedimentary layers include the Beacon Supergroup

sandstone Sandstone is a Clastic rock#Sedimentary clastic rocks, clastic sedimentary rock composed mainly of grain size, sand-sized (0.0625 to 2 mm) silicate mineral, silicate grains, Cementation (geology), cemented together by another mineral. Sand ...

s, siltstones, and

coal Coal is a combustible black or brownish-black sedimentary rock, formed as rock strata called coal seams. Coal is mostly carbon with variable amounts of other Chemical element, elements, chiefly hydrogen, sulfur, oxygen, and nitrogen. Coal i ...

deposited beginning in the

Silurian The Silurian ( ) is a geologic period and system spanning 23.5 million years from the end of the Ordovician Period, at million years ago ( Mya), to the beginning of the Devonian Period, Mya. The Silurian is the third and shortest period of t ...

period and continuing into the

Jurassic The Jurassic ( ) is a Geological period, geologic period and System (stratigraphy), stratigraphic system that spanned from the end of the Triassic Period million years ago (Mya) to the beginning of the Cretaceous Period, approximately 143.1 Mya. ...

. In many places, the Beacon Supergroup has been intruded by dikes and sills of Jurassic age Ferrar Dolerite. Many of the

fossil A fossil (from Classical Latin , ) is any preserved remains, impression, or trace of any once-living thing from a past geological age. Examples include bones, shells, exoskeletons, stone imprints of animals or microbes, objects preserve ...

s found in Antarctica are from locations within these sedimentary formations. Ice from the East Antarctic Ice Sheet flows through the Transantarctic Mountains via a series of outlet glaciers into the Ross Sea, Ross Ice Shelf, and

West Antarctic Ice Sheet The West Antarctic Ice Sheet (WAIS) is the segment of the Antarctic ice sheet, continental ice sheet that covers West Antarctica, the portion of Antarctica on the side of the Transantarctic Mountains that lies in the Western Hemisphere. It is cla ...

. These glaciers generally flow perpendicular to the orientation of the range and define subranges and peak groups. It has been thought that many of these outlet glaciers follow the traces of large-scale geologic faults. However, the ice flow theories will be re-evaluated in light of new data from recent ice-penetrating radar surveys which revealed the presence of three previously unknown deep subglacial valleys affecting the "mountainous subglacial topography beneath the ice divide". These geographic features are likely to have a significant impact on models and calculations related to ice flow through the Transantarctic Mountain region.

References

External links

Transantarctic Mountains at Peakbagger.com
* C.Michael Hogan. 2011
''Ross Sea''. Eds. P. Saundry and C.J. Cleveland. Encyclopedia of Earth. National Council for Science and the Environment. Washington DC
{{Authority control Mountain ranges of Antarctica East Antarctica West Antarctica Mountain ranges of Coats Land Mountain ranges of Queen Maud Land Mountain ranges of Victoria Land

Geography

Biology

History

Geology

See also

Victoria Land

Central TAM

Queen Maud Mountains

"Southern" TAM

Further reading

References

External links