Antarctica
Area (Overall)
(ice-free)
(ice-covered) |
14,000,000 km2 (5,400,000 sq mi)
280,000 km2 (100,000 sq mi)
13,720,000 km2 (5,300,000 sq mi) |
Population
(permanent)
(non-permanent) |
7th
0
approx. 1,000 |
Dependencies |
|
Official Territorial lands |
Antarctic Treaty
System |
Unofficial Territorial claims |
|
Reserved the right to make claims |
|
Time Zones |
None
UTC-3 (Graham
Land only) |
Internet Top-level domain |
.aq |
Calling Code |
Dependent
on the parent country of each base |
Antarctica ( , is Earth's southernmost continent, underlying the South Pole
. It is situated in the Antarctic region of the southern
hemisphere
, almost entirely south of the Antarctic Circle, and is surrounded by the
Southern
Ocean
. At 14.0 million km² (5.4
million sq mi), it is the fifth-largest continent in area
after
Asia,
Africa,
North America, and
South America. About 98% of Antarctica is
covered by
ice, which averages at least 1.6
kilometres (1.0 mi) in thickness.
Antarctica, on average, is the coldest, driest, and windiest
continent, and has the highest average
elevation of all the continents. Antarctica is
considered a
desert, with annual
precipitation of only 200 mm (8 inches) along the coast
and far less inland. There are no permanent human residents but
anywhere from 1,000 to 5,000 people reside throughout the year at
the research stations scattered across the continent. Only
cold-adapted plants and animals survive there, including
penguins,
seals, many types
of
algae, and
tundra
vegetation.
Although myths and speculation about a
Terra Australis ("Southern Land") date
back to antiquity, the first confirmed sighting of the continent is
commonly accepted to have occurred in 1820 by the Russian
expedition of
Mikhail
Lazarev and
Fabian Gottlieb von
Bellingshausen. The continent, however, remained largely
neglected for the rest of the 19th century because of its hostile
environment, lack of resources, and isolation. The first formal use
of the name "Antarctica" as a continental name in the 1890s is
attributed to the Scottish cartographer
John George Bartholomew. The name
Antarctica is the
romanized version of the
Greek compound word
ανταρκτική
(
antarktiké), feminine of
ανταρκτικός
(
antarktikos), meaning "opposite to the north".
The
Antarctic Treaty was
signed in 1959 by twelve countries; to date, forty-six countries
have signed the treaty. The treaty prohibits military activities
and mineral mining, supports scientific research, and protects the
continent's
ecozone. Ongoing experiments are
conducted by more than 4,000 scientists of many nationalities and
with different research interests.
History
Belief in the existence of a
Terra Australis — a vast
continent in the far south of the globe to "balance" the northern
lands of
Europe,
Asia and
North Africa — had existed since the
times of
Ptolemy (1st century AD), who
suggested the idea to preserve the
symmetry
of all known
landmasses in the world.
Depictions of a large southern landmass were common in maps such as
the early 16th century
Turkish
Piri Reis map. Even in the late 17th
century, after explorers had found that South America and Australia
were not part of the fabled "Antarctica", geographers believed that
the continent was much larger than its actual size.
European maps continued to show this hypothetical land until
Captain
James Cook's ships,
HMS Resolution and
Adventure, crossed the
Antarctic Circle on 17 January
1773, in December 1773 and again in January 1774. Cook in fact came
within about of the Antarctic coast before retreating in the face
of field ice in January 1773. The first confirmed sighting of
Antarctica can be narrowed down to the crews of ships captained by
three individuals.
According to various organizations (the
National Science
Foundation, NASA
, the
University of California, San
Diego
, and other sources), ships captained by three men
sighted Antarctica in 1820: Fabian Gottlieb von
Bellingshausen (a captain in the Russian Imperial Navy), Edward Bransfield (a captain in the
Royal Navy), and Nathaniel Palmer (an American sealer out of Stonington,
Connecticut
). Von Bellingshausen saw Antarctica on 27
January 1820, three days before Bransfield sighted land, and ten
months before Palmer did so in November 1820. On that day the
two-ship expedition led by Von Bellingshausen and
Mikhail Petrovich Lazarev reached
a point within 32 kilometers (20 mi) of the Antarctic mainland
and saw ice fields there.
The first documented landing on mainland
Antarctica was by the American sealer John Davis in West Antarctica
on 7 February 1821, although some historians
dispute this claim.
In December, 1839, as part of the
United States Exploring
Expedition of 1838–42 conducted by the
United States Navy (sometimes called the
"Ex.
Ex.",
or "the Wilkes Expedition"), an expedition sailed from Sydney
, Australia,
into the Antarctic
Ocean
, as it was then known, and reported the discovery
"of an Antarctic continent west of the Balleny Islands". That part of
Antarctica was later named "
Wilkes
Land", a name it maintains to this day.
Explorer
James Clark Ross passed through
what is now known as the Ross
Sea
and discovered Ross Island
(both of which were named for him) in 1841.
He sailed
along a huge wall of ice that was later named the Ross Ice Shelf
(also named for him). Mount Erebus
and Mount Terror
are named after two ships from his expedition:
HMS Erebus and
Terror.
Mercator Cooper landed in East
Antarctica
on 26
January 1853.
During the
Nimrod Expedition led
by
Ernest Shackleton in 1907,
parties led by
T. W. Edgeworth
David became the first to climb Mount Erebus
and to reach the South Magnetic Pole. Douglas Mawson, who assumed the leadership of
the Magnetic Pole party on their perilous return, went on to lead
several expeditions until retiring in 1931.
In addition,
Shackleton himself and three other members of his expedition made
several firsts in December 1908 – February 1909: they were the
first humans to traverse the Ross Ice Shelf
, the first to traverse the Transantarctic Mountain
Range (via the Beardmore
Glacier
), and the first to set foot on the South Polar
Plateau. An expedition led by Norwegian
polar explorer Roald Amundsen from
the ship Fram
became
the first to reach the geographic South Pole
on 14 December 1911, using a route from the
Bay of
Whales
and up the Axel Heiberg Glacier
. One month later, the ill-fated
Scott Expedition reached the
pole.
Richard Evelyn Byrd led several
voyages to the Antarctic by plane in the 1930s and 1940s. He is
credited with implementing mechanized land transport on the
continent and conducting extensive geological and biological
research. However, it was not until 31 October 1956 that anyone set
foot on the South Pole again; on that day a U.S. Navy group led by
Rear Admiral
George J. Dufek successfully landed an aircraft
there.
The first
person to sail single-handed to Antarctica was the New Zealander
David Henry Lewis,
in a 10-meter steel sloop Ice Bird.
Geography

A satellite composite image of
Antarctica

Elevation colorized relief
Centered
asymmetrically around the South Pole
and largely south of the Antarctic Circle, Antarctica is the
southernmost continent and is surrounded by the Southern Ocean
; alternatively, it may be considered to be
surrounded by the southern Pacific
, Atlantic
, and Indian
Oceans
, or by the southern waters of the World Ocean. It covers more than , making
it the fifth-largest continent, about 1.3 times as large as
Europe. The coastline measures and is mostly
characterized by
ice formations, as the
following table shows:
Coastal types around Antarctica (Drewry,
1983)
Type |
Frequency |
Ice shelf (floating ice front) |
44% |
Ice walls (resting on ground) |
38% |
Ice stream/outlet glacier (ice front or ice wall) |
13% |
Rock |
5% |
Total |
100% |

Maritime Antarctica
Antarctica is divided in two by the Transantarctic Mountains
close to the neck between the Ross Sea
and the Weddell Sea
. The portion west of the Weddell Sea and east
of the Ross Sea is called West Antarctica
and the remainder East Antarctica
, because they roughly correspond to the Western and
Eastern Hemispheres relative to the Greenwich meridian.
About 98% of Antarctica is covered by the
Antarctic ice sheet, a
sheet of ice averaging at least thick. The
continent has about 90% of the world's ice (and thereby about 70%
of the world's
fresh water). If all of
this ice were melted, sea levels would rise about . In most of the
interior of the continent,
precipitation is very low, down
to per year; in a few "
blue ice"
areas precipitation is lower than mass loss by
sublimation and so the local mass
balance is negative.
In the dry valleys
the same effect occurs over a rock base, leading to
a desiccated landscape.
West
Antarctica
is covered
by the West Antarctic Ice
Sheet. The sheet has been of recent concern because of
the real, if small, possibility of its collapse. If the sheet were
to break down,
ocean levels would
rise by several metres in a relatively
geologically short period of time,
perhaps a matter of centuries. Several Antarctic
ice streams, which account for about 10% of the
ice sheet,
flow to one of the
many
Antarctic ice
shelves.
East
Antarctica
lies on the
Indian
Ocean
side of the Transantarctic Mountains
and comprising Coats Land
, Queen Maud Land,
Enderby
Land
, Mac Robertson
Land, Wilkes Land and Victoria Land. All but a small portion
of this region lies within the
Eastern Hemisphere. East Antarctica is
largely covered by the
East
Antarctic Ice Sheet.
Vinson Massif
, the highest peak in Antarctica at , is located in
the Ellsworth
Mountains
. Antarctica contains
many other mountains, both
on the main continent and the surrounding islands.
Located on Ross Island
, Mount
Erebus
is the world's southernmost active volcano.
Another
well-known volcano is found on Deception Island
, which is famous for a giant eruption in
1970. Minor eruptions are frequent and lava flow has been
observed in recent years. Other dormant volcanoes may potentially
be active.
In 2004, an underwater volcano was found in
the Antarctic
Peninsula
by American and Canadian researchers. Recent
evidence shows this unnamed volcano may be active.
Antarctica is home to more than 70
lakes that
lie at the base of the continental ice sheet.
Lake Vostok
, discovered beneath Russia's Vostok
Station
in 1996, is the largest of these subglacial lakes. It was once
believed that the lake had been sealed off for 500,000 to one
million years but a recent survey suggests that, every so often,
there are large flows of water from one lake to another.
There is some evidence, in the form of
ice
cores drilled to about above the water line, that Lake Vostok's
waters may contain
microbial life. The
frozen surface of the lake shares similarities with
Jupiter's moon
Europa.
If life is discovered in Lake Vostok, this would strengthen the
argument for the possibility of life on Europa.
On 7 February 2008, a
NASA team embarked on a mission to Lake Untersee
, searching for extremophiles in its highly alkaline
waters. If found, these resilient creatures could further
bolster the argument for extraterrestrial life in extremely cold,
methane-rich environments.
Geology
Geological history and paleontology
More than 170 million years ago, Antarctica was part of the
supercontinent Gondwana. Over time, Gondwana gradually broke apart
and Antarctica as we know it today was formed around 25 million
years ago.
Paleozoic era (540–250 Ma)

Survey route
During the
Cambrian periodic stage,
Gondwana had a mild climate.
West Antarctica was partially in the
Northern
Hemisphere
, and during this period large amounts of sandstones, limestones
and shales were deposited. East
Antarctica was at the equator, where sea floor
invertebrates and
trilobites flourished in the tropical seas. By the
start of the
Devonian period
(416
Ma), Gondwana was in more southern
latitudes and the climate was cooler, though fossils of land plants
are known from this time.
Sand and silts were laid down in what is now the Ellsworth
, Horlick
and Pensacola
Mountains. Glaciation began
at the end of the Devonian period (360 Ma), as Gondwana became
centered around the South
Pole
and the climate cooled, though flora remained. During the
Permian period, the plant life became dominated by
fern-like plants such as
Glossopteris, which grew in swamps.
Over time
these swamps became deposits of coal in the Transantarctic Mountains
. Towards the end of the Permian period,
continued warming led to a dry, hot climate over much of
Gondwana.
Mesozoic era (250–65 Ma)
As a result of continued warming, the polar ice caps melted and
much of Gondwana became a desert. In East Antarctica, the
seed fern became established, and large amounts of
sandstone and shale were laid down at this time. The Antarctic
Peninsula began to form during the
Jurassic
period (206–146 Ma), and islands gradually rose out of the
ocean.
Ginkgo trees and
cycads were plentiful during this period, as were
reptiles such as
Lystrosaurus.
In West Antarctica,
coniferous forests dominated through the entire
Cretaceous period (146–65 Ma), though
Southern beech began to take over at the
end of this period.
Ammonites were common
in the seas around Antarctica, and dinosaurs were also present,
though only two Antarctic dinosaur
genera
(
Cryolophosaurus, from the
Hanson Formation, and
Antarctopelta) have been
described to date. It was during this period that Gondwana began to
break up.
Gondwanaland breakup (160–23 Ma)
The cooling of Antarctica occurred stepwise, as the continental
spread changed the oceanic currents from longitudinal
equator-to-pole temperature-equalizing currents to latitudinal
currents that preserved and accentuated latitude temperature
differences.
Africa separated from Antarctica around 160 Ma, followed by
the
Indian subcontinent, in the
early Cretaceous (about 125 Ma). About 65 Ma, Antarctica
(then connected to Australia) still had a tropical to subtropical
climate, complete with a
marsupial
fauna.
About 40 Ma Australia-New Guinea
separated from Antarctica, so that latitudinal
currents could isolate Antarctica from Australia, and the first ice
began to appear. During the
Eocene-Oligocene extinction
event about 34 million years ago; CO
2 levels have
been found to be about 760 ppm and had been decreasing from earlier
levels in the thousands of ppm.
Around 23 Ma, the Drake Passage
opened between Antarctica and South America,
resulting in the Antarctic
Circumpolar Current that completely isolated the
continent. Models of the changes suggest that declining
CO
2 levels became more important. The ice began to
spread, replacing the forests that then covered the continent.
Since about 15 Ma, the continent has been mostly covered with
ice, with the Antarctic ice cap reaching its present extension
around 6 Ma.
Geology of present-day Antarctica
The geological study of Antarctica has been greatly hindered by the
fact that nearly all of the continent is permanently covered with a
thick layer of ice. However, new techniques such as
remote sensing,
ground-penetrating radar and
satellite imagery have begun to
reveal the structures beneath the ice.
Geologically, West Antarctica closely resembles the
Andes mountain range of South America.
The Antarctic
Peninsula
was formed by uplift and metamorphism of sea bed sediments during the
late Paleozoic and the early Mesozoic eras. This sediment uplift was
accompanied by
igneous intrusions and
volcanism. The most common rocks in West
Antarctica are
andesite and
rhyolite volcanics formed during the Jurassic
period.
There is also evidence of volcanic activity,
even after the ice sheet had formed, in Marie Byrd Land and Alexander
Island
. The only anomalous area of West Antarctica
is the Ellsworth
Mountains
region, where the stratigraphy is more similar to the eastern
part of the continent.

Antarctica without its ice
sheet.
This map does not consider that sea level would rise because
of the melted ice, nor that the landmass would rise by several
hundred meters over a few tens of thousands of years after the
weight of the ice was no longer depressing the landmass.
East Antarctica is geologically very varied, dating from the
Precambrian era, with some rocks formed
more than 3 billion years ago. It is composed of a
metamorphic and
igneous platform which is the basis of the
continental shield.
On top of this base
are various modern rocks, such as sandstones, limestones,
coal and shales laid down
during the Devonian and Jurassic periods to form the Transantarctic Mountains
. In coastal areas such as Shackleton
Range
and Victoria Land some
faulting has occurred.
The main
mineral resource known on the
continent is coal.
It was first recorded near the Beardmore
Glacier
by Frank Wild on the
Nimrod Expedition, and now
low-grade coal is known across many parts of the Transantarctic
Mountains. The
Prince
Charles Mountains contain significant deposits of
iron ore.
The most valuable resources of Antarctica
lie offshore, namely the oil and natural gas fields found in the Ross Sea
in 1973. Exploitation of all mineral
resources is
banned until the year 2048 by
the
Protocol
on Environmental Protection to the Antarctic Treaty.
Climate
Antarctica is the coldest place on
Earth.
The
coldest natural temperature ever recorded on Earth was at the
Russian
Vostok
Station
in Antarctica on 21 July 1983. For
comparison, this is 11 °C (20 °F) colder than
subliming dry
ice. Antarctica is a frozen desert with little
precipitation; the South Pole
itself receives less than per year, on average. Temperatures reach
a minimum of between and in the interior in winter and reach a
maximum of between and near the coast in summer. Sunburn is often a
health issue as the snow surface reflects almost all of the
ultraviolet light falling on it.
East Antarctica is colder than its western counterpart because of
its higher elevation.
Weather fronts
rarely penetrate far into the continent, leaving the center cold
and dry. Despite the lack of precipitation over the central portion
of the continent,
ice there lasts for extended
time periods. Heavy snowfalls are not uncommon on the coastal
portion of the continent, where snowfalls of up to in 48 hours have
been recorded.
At the edge of the continent, strong
katabatic winds off the
polar plateau often blow at storm force. In
the interior, however, wind speeds are typically moderate. During
summer, more
solar radiation reaches
the surface during clear days at the South Pole than at the
equator because of the 24 hours of sunlight
each day at the Pole.
Antarctica is colder than the
Arctic for two
reasons. First, much of the continent is more than above sea level,
and temperature decreases with elevation.
Second, the Arctic Ocean
covers the north polar zone: the ocean's relative
warmth is transferred through the icepack and prevents temperatures
in the Arctic regions from reaching the extremes typical of the
land surface of Antarctica.

Mountain glaciation
Given the latitude, long periods of constant darkness or constant
sunlight create climates unfamiliar to human beings in much of the
rest of the world. The
aurora
australis, commonly known as the southern lights, is a glow
observed in the night sky near the South Pole created by the
plasma-full
solar winds that pass by the
Earth. Another unique spectacle is
diamond
dust, a ground-level cloud composed of tiny ice crystals. It
generally forms under otherwise clear or nearly clear skies, so
people sometimes also refer to it as clear-sky precipitation. A
sun dog, a frequent atmospheric
optical phenomenon, is a bright "spot"
beside the true
sun.
Population
Antarctica has no permanent residents, but a number of governments
maintain permanent manned
research
stations throughout the continent. The number of people
conducting and supporting scientific research and other work on the
continent and its nearby islands varies from about 1,000 in winter
to about 5,000 in the summer. Many of the stations are staffed
year-round, the winter-over personnel typically arriving from their
home countries for a one-year assignment.
An Orthodox
church
opened in 2004 at the Russian Bellingshausen Station is also manned
year-round by one or two priests, who are similarly rotated every
year.
The first semi-permanent inhabitants of regions near Antarctica
(areas situated south of the
Antarctic Convergence) were British
and American sealers who used to spend a year or more on
South Georgia, from 1786 onward. During
the
whaling era, which lasted until 1966,
the population of that island varied from over 1,000 in the summer
(over 2,000 in some years) to some 200 in the winter. Most of the
whalers were Norwegian, with an increasing proportion of Britons.
The
settlements included Grytviken
, Leith Harbour,
King Edward Point, Stromness
, Husvik
, Prince Olav
Harbour
, Ocean
Harbour
and Godthul
. Managers and other senior officers of the
whaling stations often lived together with their families. Among
them was the founder of Grytviken, Captain
Carl Anton Larsen, a prominent Norwegian
whaler and explorer who, along with his family, adopted British
citizenship in 1910.

Field work being carried out on Melnik
Peak, Livingston Island
The first
child born in the southern polar
region was Norwegian girl Solveig Gunbjørg Jacobsen,
born in Grytviken on 8 October 1913, and her birth was registered
by the resident British Magistrate of South Georgia
. She was a daughter of Fridthjof Jacobsen,
the assistant manager of the whaling station, and of Klara Olette
Jacobsen. Jacobsen arrived on the island in 1904 to become the
manager of Grytviken, serving from 1914 to 1921; two of his
children were born on the island.
Emilio Marcos Palma was the first person
born south of the 60th parallel
south (the continental limit according to the Antarctic Treaty), as well as the first one
born on the Antarctic mainland, in 1978 at Base Esperanza, on the tip of the Antarctic
Peninsula
; his parents were sent there along with seven other
families by the Argentine
government to determine if family life was suitable
on the continent. In 1984, Juan Pablo Camacho was born at
the
Frei Montalva
Station, becoming the first Chilean born in Antarctica. Several
bases are now home to families with children attending schools at
the station. As of 2009, eleven children were born in Antarctica
(south of the 60th parallel south): eight at the Argentinean
Esperanza Base and three at the
Chilean
Frei
Montalva Station.
Flora and fauna
Flora
The climate of Antarctica does not allow extensive vegetation. A
combination of freezing temperatures, poor
soil
quality, lack of moisture, and lack of sunlight inhibit the
flourishing of plants. As a result, plant life is limited to mostly
mosses and
liverwort. The
autotrophic community is made up of mostly
protists. The
flora of
the continent largely consists of
lichens,
bryophytes,
algae,
and
fungi. Growth generally occurs in the
summer, and only for a few weeks at most.
There are more than 200 species of lichens and about 50 species of
bryophytes, such as mosses. Seven hundred species of algae exist,
most of which are
phytoplankton.
Multicolored
snow algae and
diatoms are especially abundant in the coastal
regions during the summer. There are two species of flowering
plants found in the Antarctic Peninsula:
Deschampsia antarctica
(Antarctic hair grass) and
Colobanthus quitensis (Antarctic
pearlwort).
Fauna
Few terrestrial
vertebrates live in
Antarctica. Invertebrate life includes
microscopic mites like the
Alaskozetes antarcticus,
lice,
nematode,
tardigrades,
rotifers,
krill and
springtails. Recently ancient ecosystems
consisting of several types of bacteria have been found living
trapped deep beneath glaciers. The flightless
midge Belgica antarctica, just in size, is
the largest purely terrestrial animal in Antarctica. The
Snow Petrel is one of only three birds that
breed exclusively in Antarctica.
A variety of marine animals exist and rely, directly or indirectly,
on the phytoplankton. Antarctic sea life includes
penguins,
blue whales,
orcas,
colossal
squids and
fur seals. The
Emperor penguin is the only penguin that
breeds during the winter in Antarctica, while the
Adélie Penguin breeds farther south than any
other penguin. The
Rockhopper
penguin has distinctive feathers around the eyes, giving the
appearance of elaborate eyelashes.
King
penguins,
Chinstrap penguins,
and
Gentoo Penguins also breed in the
Antarctic.
The
Antarctic fur seal was very
heavily hunted in the 18th and 19th centuries for its pelt by
sealers from the United States and the United Kingdom.
The Weddell Seal, a "true
seal", is named after Sir James
Weddell, commander of British
sealing expeditions in the Weddell Sea
. Antarctic
krill, which congregates in large schools, is the keystone species of the ecosystem of the Southern Ocean
, and is an important food organism for whales,
seals, leopard seals, fur seals,
squid, icefish,
penguins, albatrosses and many other
birds.
The passing of the
Antarctic
Conservation Act in the U.S. brought several restrictions to
U.S. activity on the continent. The introduction of alien plants or
animals can bring a criminal penalty, as can the extraction of any
indigenous species. The
overfishing of
krill, which plays a large role in the Antarctic ecosystem, led
officials to enact regulations on
fishing.
The Convention for the Conservation of Antarctic Marine Living
Resources (CCAMLR), a treaty that came into force in 1980, requires
that regulations managing all Southern Ocean fisheries consider
potential effects on the entire Antarctic ecosystem. Despite these
new acts, unregulated and illegal fishing, particularly of
Patagonian toothfish (marketed as
Chilean Sea Bass in the U.S.), remains a serious problem. The
illegal fishing of toothfish has been increasing, with estimates of
32,000
tonnes (35,300 short
tons) in 2000.
A census of sea life carried out during the
International Polar Year and which
involved some 500 researchers is due for release in 2010. The
research is part of the global
Census of Marine Life (CoML) and has
disclosed some remarkable findings. More than 235 marine organisms
live in both polar regions, having bridged the gap of
12 000 km. Large animals such as some cetaceans and birds
make the round trip annually. More surprising are small forms of
life such as mudworms,
sea cucumbers
and free-swimming snails found in both polar oceans. Various
factors may aid in their distribution - fairly uniform temperatures
of the deep ocean at the poles and the equator which differ by no
more than 5°C, and the major current systems or marine
conveyor belt which transport egg
and larvae stages.
Politics
Antarctica has no government and belongs to no country. Various
countries claim areas of it but, while some have mutually
recognized each other's claims, no other countries recognize such
claims.
New claims on Antarctica have been suspended since 1959 and the
continent is considered politically neutral. Its status is
regulated by the 1959
Antarctic
Treaty and other related agreements, collectively called the
Antarctic Treaty System.
Antarctica is defined as all land and
ice
shelves south of 60° S for the purposes of the Treaty System.
The
treaty was signed by twelve countries including the Soviet Union
(and later Russia), the United Kingdom
, Argentina
, Chile
, Australia, and the United States
. It set aside Antarctica as a scientific
preserve, established freedom of scientific investigation and
environmental protection, and banned military activity on the
continent. This was the first
arms
control agreement established during the
Cold War.
In 1983, the Antarctic Treaty Parties began negotiations on a
convention to regulate mining in Antarctica. A coalition of
international organisations launched a public pressure campaign to
prevent any minerals development in the region, led largely by
Greenpeace International
which established its own scientific station –
World Park Base – in the Ross Sea region and
conducted annual expeditions to document environmental effects of
humans on the continent. In 1988, the Convention on the Regulation
of Antarctic Mineral Resources (CRAMRA) was adopted. The following
year, however, Australia and France announced that they would not
ratify the convention, rendering it dead for all intents and
purposes. They proposed instead that a comprehensive regime to
protect the Antarctic environment be negotiated in its place. The
Protocol on Environmental Protection to the Antarctic Treaty (the
‘Madrid Protocol’) was negotiated as other countries followed suit
and on 14 January 1998 it entered into force. The Madrid Protocol
bans all mining in Antarctica, designating the continent as a
‘natural reserve devoted to peace and science’.
The Antarctic Treaty prohibits any
military activity in
Antarctica, including the establishment of military bases and
fortifications, military manoeuvers, and weapons testing. Military
personnel or equipment are permitted only for scientific research
or other peaceful purposes. The only documented military land
manoeuvre was
Operation NINETY by
the
Argentine military.
The
United States military
issues the
Antarctica Service
Medal to military members or civilians who perform research
duty in Antarctica. The medal includes a "wintered over" bar issued
to those who remain on the continent for 2 six-month seasons.
Antarctic territories
The Argentine, British, and Chilean claims all overlap, and have
caused friction. The areas shown as
Australia's and
New Zealand's claims were British territory
until they were handed over following the countries' independence.
Australia currently claims the largest area.
Countries interested in participating in a possible territorial
division of Antarctica
This group of countries participating as members of Antarctica
Treaty have a territorial interest in the Antarctic continent but
the provisions of the Treaty do not allow them to make their claims
while it is in force.
- has a designated 'zone of interest' that is not an actual
claim.
- has formally reserved its right to make a claim.
- has reserved its right to claim "territories discovered by
Russians", which potentially may refer to the entire
continent.
- has formally reserved its right to make a claim.
- has formally reserved its right to make a claim.
- has formally reserved its right to make a claim.
Economy
Although
coal,
hydrocarbons,
iron ore,
platinum,
copper,
chromium,
nickel,
gold and other minerals have been found, they
have not been in large enough quantities to exploit. The 1991
Protocol
on Environmental Protection to the Antarctic Treaty also
restricts a struggle for resources. In 1998, a compromise agreement
was reached to place an indefinite ban on mining, to be reviewed in
2048, further limiting economic development and exploitation. The
primary economic activity is the capture and offshore trading of
fish. Antarctic fisheries in 2000–01 reported landing
112,934 tonnes.
Small-scale "expedition
tourism" has existed
since 1957 and is currently subject to Antarctic Treaty and
Environmental Protocol provisions, but in effect self-regulated by
the
International
Association of Antarctica Tour Operators (IAATO). Not all
vessels associated with Antarctic tourism are members of IAATO, but
IAATO members account for 95% of the tourist activity. Travel is
largely by small or medium
ship, focusing on
specific scenic locations with accessible concentrations of iconic
wildlife.
A total of 37,506 tourists visited during
the 2006–07 Austral
summer
with nearly all of them coming from commercial
ships. The number is predicted to increase to over 80,000 by
2010.
There has been some recent concern over the potential adverse
environmental and ecosystem effects caused by the influx of
visitors. A call for stricter regulations for ships and a tourism
quota have been made by some environmentalists and scientists. The
primary response by Antarctic Treaty Parties has been to develop,
through their Committee for Environmental Protection and in
partnership with IAATO, "site use guidelines" setting landing
limits and closed or restricted zones on the more frequently
visited sites.
Antarctic sight seeing flights (which did
not land) operated out of Australia and New Zealand until the fatal
crash of Air New Zealand Flight 901
in 1979 on Mount Erebus
, which killed all 257 aboard. Qantas resumed commercial overflights to Antarctica
from Australia in the mid-1990s.
Transport
Transport on the continent has transformed from explorers crossing
the isolated remote area of Antarctica on foot to a more open area
due to human technologies enabling more convenient and faster
transport by land and predominantly by air and water. The use of
dogs to pull researchers and sledges has been banned on objections
that dogs are an alien species to Antarctica.
Research
Each year, scientists from 27 different nations conduct
experiments not reproducible in any other place
in the world. In the summer more than 4,000 scientists operate
research stations; this number
decreases to nearly 1,000 in the winter.
McMurdo
Station
is capable of housing more than 1,000 scientists,
visitors, and tourists.
Researchers include
biologists,
geologists,
oceanographers,
physicists,
astronomers,
glaciologists, and
meteorologists. Geologists tend to study
plate tectonics, meteorites from
outer space, and resources from the breakup of
the supercontinent
Gondwanaland.
Glaciologists in Antarctica are concerned with the study of the
history and
dynamics of floating
ice,
seasonal snow,
glaciers, and
ice sheets.
Biologists, in addition to examining the wildlife, are interested
in how harsh temperatures and the presence of people affect
adaptation and survival strategies in a wide variety of organisms.
Medical physicians have made discoveries concerning the spreading
of viruses and the body's response to extreme seasonal
temperatures.
Astrophysicists at Amundsen-Scott South Pole
Station
study the celestial dome and cosmic microwave
background radiation. Many astronomical observations are
better made from the interior of Antarctica than from most surface
locations because of the high elevation, which results in a thin
atmosphere, low temperature, which minimizes the amount of water
vapour in the atmosphere, and absence of
light pollution, thus allowing for a view of
space clearer than anywhere else on Earth. Antarctic ice serves as
both the shield and the detection medium for the largest
neutrino telescope in the world, built 2 kilometers
below Amundsen-Scott station.
Since the 1970s, an important focus of study has been the
ozone layer in the
atmosphere above Antarctica.
In 1985, three
British Scientists working on data they had gathered at Halley
Station
on the Brunt Ice Shelf
discovered the existence of a hole in this
layer. In 1998, NASA
satellite
data showed that the Antarctic ozone hole
was the largest on record, covering 27 million km² (10
million sq mi). It was eventually determined that
the destruction of the ozone was caused by
chlorofluorocarbons
emitted by human products. With the ban of CFCs in the
Montreal Protocol of 1989, it is believed
that the ozone hole will close up over the next fifty years.
Princess Elisabeth Polar Science Station
On 6
September 2007, Belgian
-based International Polar Foundation unveiled the
Princess Elisabeth station,
the world's first zero-emissions polar science station in
Antarctica to research climate change. Costing $16.3
million, the prefabricated station,
which is part of International
Polar Year, was shipped to the South Pole
from Belgium
by the end of 2008 to monitor the health of the polar
regions. Belgian polar
explorer
Alain Hubert stated: "This base will be
the first of its kind to produce zero emissions, making it a unique
model of how energy should be used in the Antarctic."
Johan Berte is the leader of the station design
team and manager of the project which conducts research in
climatology,
glaciology and
microbiology.
Meteorites
Meteorites from Antarctica are an
important area of study of material formed early in the
solar system; most are thought to come from
asteroids, but some may have originated on
larger
planets. The first meteorites were
found in 1912. In 1969, a Japanese expedition discovered nine
meteorites. Most of these meteorites have fallen onto the
ice sheet in the last million years. Motion of the
ice sheet tends to concentrate the meteorites at blocking locations
such as mountain ranges, with wind erosion bringing them to the
surface after centuries beneath accumulated snowfall. Compared with
meteorites collected in more temperate regions on Earth, the
Antarctic meteorites are well-preserved.
This large collection of meteorites allows a better understanding
of the abundance of meteorite types in the solar system and how
meteorites relate to asteroids and comets. New types of meteorites
and rare meteorites have been found. Among these are pieces blasted
off the Moon, and probably Mars, by impacts.
These specimens,
particularly ALH84001
discovered by ANSMET, are at
the center of the controversy about possible evidence of microbial
life on Mars. Because meteorites in space absorb and record
cosmic radiation, the time elapsed since the meteorite hit the
Earth can be determined from laboratory studies. The elapsed time
since fall, or terrestrial residence age, of a meteorite represents
more information that might be useful in environmental studies of
Antarctic ice sheets.
In 2006,
a team of researchers from Ohio State University
used gravity measurements by NASA's GRACE satellites to
discover the -wide Wilkes Land crater
, which probably formed about 250 million years
ago.
Volcanic 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 Antarctica ice sheet
(based on
airborne survey with radar
images).
The biggest eruption in Antarctica 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
.
Ice mass and global sea level
Due to its location at the South Pole, Antarctica receives
relatively little solar radiation. This means that it is a very
cold continent where water is mostly in the form of ice.
Precipitation is low (most of Antarctica is a
desert) and almost always in the form of snow, which
accumulates and forms a giant
ice sheet
which covers the land. Parts of this ice sheet form moving glaciers
known as
ice streams, which flow towards
the edges of the continent. Next to the continental shore are many
ice shelves. These are floating extensions
of outflowing glaciers from the continental ice mass. Offshore,
temperatures are also low enough that ice is formed from
seawater through most of the year. It is important
to understand the various types of Antarctic ice to understand
possible effects on sea levels and the implications of global
warming.
Sea ice expands annually in the Antarctic winter and melts in the
summer. This ice is formed from the ocean water and floats in the
same water and thus does not contribute to rise in sea level. The
extent of
sea ice around Antarctica has
remained roughly constant in recent decades, although the thickness
changes are unclear.
Melting of floating
ice shelves (ice that
originated on the land) does not in itself contribute much to
sea-level rise (since the ice displaces only its own mass of
water). However it is the outflow of the ice from the land to form
the ice shelf which causes a rise in global sea level. This effect
is offset by snow falling back onto the continent.
Recent decades have
witnessed several dramatic collapses of large ice shelves around
the coast of Antarctica, especially along the Antarctic
Peninsula
. Concerns have been raised that disruption
of ice shelves may result in increased glacial outflow from the
continental ice mass.
On the continent itself, the large volume of ice present stores
around 70 % of the world's fresh water. This
ice sheet is constantly gaining ice from snowfall
and losing ice through outflow to the sea. West Antarctica is
currently experiencing a net outflow of glacial ice, which will
increase global sea level over time. A review of the scientific
studies looking at data from 1992 to 2006 suggested a net loss of
around 50
Gigatonnes of ice per year was
a reasonable estimate (around 0.14 mm of sea level rise).
Significant acceleration of outflow glaciers in the
Amundsen Sea Embayment may have more
than doubled this figure for the year 2006.
East Antarctica is a cold region with a ground base above sea level
and occupies most of the continent. This area is dominated by small
accumulations of snowfall which becomes ice and thus eventually
seaward glacial flows. The mass balance of the
East Antarctic Ice Sheet as a whole
is thought to be slightly positive (lowering sea level) or near to
balance. However, increased ice outflow has been suggested in some
regions.
Effects of global warming
Some of
Antarctica has been warming up, particularly strong warming has
been noted on the Antarctic Peninsula
. A study by Eric Steig published in 2009
noted for the first time that the continent-wide average surface
temperature trend of Antarctica is slightly positive at
>0.05 °C (0.09 °F) per decade from 1957 to 2006. This
study also noted that West Antarctica has warmed by more than
0.1 °C (0.2 °F) per decade in the last 50 years, and this
warming is strongest in winter and spring. Although this is partly
offset by fall cooling in East Antarctica. There is evidence from
one study that Antarctica is
warming
as a result of human emissions. However, the small amount of
surface warming in West Antarctica is not believed to be directly
affecting the
West Antarctic
Ice Sheet's contribution to sea level. Instead the recent
increases in glacier outflow are believed to be due to an inflow of
warm water from the deep ocean, just off the
continental shelf. The net contribution to
sea level from the Antarctic Peninsula is more likely to be a
direct result of the much greater atmospheric warming there.
In 2003 the Antarctic Peninsula's
Larsen-B ice shelf collapsed.
Between
28 February and 8 March 2008, about of ice from the Wilkins Ice Shelf
on the southwest part of the peninsula collapsed,
putting the remaining of the ice shelf at risk. The ice was
being held back by a "thread" of ice about 6 km wide, prior to
its collapse on
April 5, 2009.
According to NASA
, the most
widespread Antarctic surface melting of the past 30 years occurred
in 2005, when an area of ice comparable in size to California
briefly melted and refroze; this may have resulted
from temperatures rising to as high as .
Ozone depletion
Each year a large area of decreased ozone concentration or
"ozone hole" grows over Antarctica. This hole
covers the whole continent and is at its largest in September. The
year 2008 saw the longest lasting hole on record, which remained
until the end of December. The hole was detected by scientists in
1985 and has tended to increase over the years of observation. The
ozone hole is attributed to the
emission of
chlorofluorocarbons or CFCs into the
atmosphere, which decompose the
ozone into other gases.
Some scientific studies suggest that ozone depletion may have a
dominant role in the recent climate changes in Antarctica (and a
wider area of the Southern Hemisphere). Ozone absorbs large amounts
of ultraviolet radiation in the
stratosphere. Ozone depletion over Antarctica
can cause a cooling of around 6°C in the local stratosphere. This
cooling has the effect of intensifying the westerly winds which
flow around the continent (the
polar
vortex) and thus prevents outflow of the cold air near the
South Pole. As a result, the continental mass of the East Antarctic
ice sheet is held at lower temperatures, and the peripheral areas
of Antarctica, especially the Antarctic Peninsula, are subject to
higher temperatures, which promote accelerated melting. Recent
models also suggest that the ozone depletion/enhanced polar vortex
effect also accounts for the recent increase in sea-ice just
offshore of the continent.
See also
Geographic regions
Geography
Geopolitics
Other
References
- Antarktikos, Henry George Liddell, Robert
Scott, A Greek-English Lexicon, at Perseus
- James Cook, The Journals, edited by Philip Edwards.
Penguin Books, 2003, p. 250.
- and
- New CO2 data helps unlock the secrets of Antarctic
formation September 13th, 2009
- (Interview with Father Vladimir Petrakov, a priest who twice
spent a year at the station)
- R.K. Headland, The Island of South Georgia, Cambridge
University Press, 1984.
- The text of the Antarctic Treaty, article VI ("Area covered by
Treaty") states: "The provisions of the present Treaty shall apply
to the area south of 60º South latitude"
- Explorer's Gazette Volume 9,
Issue 1
- Times On Line article on Antarctica
- Registro Civil Base Esperanza (in Spanish)
- Derechos sberanos antárticos de Chile by the
Chilean Corporación de Defensa de la Soberanía (in Spanish)
- "Australia, New Zealand, France, Norway and the United Kingdom
reciprocally recognize the validity of each other's claims."
-
http://www.afese.com/img/revistas/revista40/laantartida.pdf
- belspo.be - Princess Elisabeth Station
- >
External links