Area of Transantarctic
Mountains: 225,461 square miles
Highest peak:
(Mt. Markham): 14,275 feet
The
Transantarctic Mountains in
northern Victoria Land near
Cape Roberts [1]
The three largest mountain
ranges on the Antarctic continent
are the Transantarctic Mountains (abbreviated
TAM), the West Antarctica Ranges,
and the East Antarctica Ranges. The
Transantarctic Mountains compose a
mountain range in Antarctica which
extend, with some interruptions, across
the continent from Cape Adare in northern
Victoria Land to Coats Land. These
mountains serve as the division between
East Antarctica and West Antarctica.
They include a number of separately
named mountain groups, which are often
again subdivided into smaller ranges.
Biology
Penguins, seals, and sea birds live
along the Ross Sea coastline in Victoria
Land, while life in the interior of
the Transantarctics is limited to
lichens, algae, and fungi.
History
The Transantarctic Mountains were
first seen by Captain James Ross in
1841 from the Ross Sea. The range
is a natural barrier that must be
crossed to reach the South Pole from
the Ross Ice Shelf. In 1908, while
not making the pole, Ernest Shackleton's
party was the first to cross the mountains,
using the Beardmore Glacier. Robert
Scott returned to the Beardmore in
1911, while Roald Amundsen 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 made extensive use of aerial
photography and concentrated on a
thorough investigation of the entire
continent. The name "Transantarctic
Mountains" were recommended in
1962 by the US-ACAN committee, a US
authority for geographic names. This
purely descriptive label (in contrast
to many other geographic names of
the seventh continent) is internationally
accepted at present.
The Leverett Glacier
in the Queen Maud Mountains 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 that are mainly volcanic
in origin. The range was uplifted
during the opening of the West Antarctic
Rift to the east, beginning about
65 million years ago in the early
Cenozoic.
The mountains consist
of sedimentary layers lying upon a
basement of granites and gneisses.
The sedimentary layers include the
Beacon Supergroup sandstones, siltstones,
and coal deposited beginning in the
Silurian period and continuing into
the Jurassic. In many places the Beacon
has been intruded by dikes and sills
of Jurassic-age Ferrar Dolerite. Many
of the fossils 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. These
glaciers generally flow perpendicular
to the orientation of the range and
define subranges and peak groups.
It is thought that many of these outlet
glaciers follow the traces of large-scale
geologic faults.[2]
