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 Introduction (books)
Antarctica (“opposite to the Arctic”) is fifth in size
among the world's continents. It is almost wholly covered by a vast
ice sheet.
It covers about 5.5 million square miles (14.2 million square km).
Antarctica is effectively divided into 2 parts: the larger, East
Antarctica, is largely a high, ice-covered plateau, whilst the smaller
West Antarctica consists of mountainous islands covered and fused
together by ice. East and West Antarctica are divided by the 1,900-mile-long
Transantarctic Mountains.
The continental ice sheet contains about 7 million cubic miles
(30 million cubic km) of ice, or about 90 percent of the world's
total. Average thickness of the ice is about 6,500 ft (2,000m).
Around the Antarctic coast, glaciers, shelves, and ice sheets are
in constant flux, continually calving icebergs into the seas.
The extreme features of Antarctica, the isolation from other continents,
the unpredictable weather and freezing temperatures, have prevented
the settlement of any native population. Antarctica today is a spectacular
wilderness, isolated in human and historic terms.
Antarctica is the only continent which remained unknown to man
until 200 years ago, when a spirit of adventure and scientific curiosity
first attracted the early explorers. Once the existence of Antarctica
was confirmed, its unique environment restricted access for most
human purposes. Today the nations of the world appear to agree to
continue its unique status as a free and open land of international
co-operation, scientific research and unsullied beauty.
Wildlife
The climate of Antarctica is one of the most extreme in the world.
Due to these harsh conditions the animals that came to reside here
have developed many unique adaptations in order to survive and are
now dependent on this continent. Most of the flora and fauna in
Antarctica is concentrated in coastal and marine areas. The land
ecosystem is therefore extremely restricted and almost all life
systems depend on the sea, which provides the resources for the
survival of most species.
The biological productivity in Antarctic waters is higher than
in any other waters in the world. The seawater is very cold, and
can hold dissolved gasses, such as carbon dioxide and oxygen better
than warmer waters. The area is also very windy, which causes the
storm-tossed seas to keep essential nutrients such as phosphates,
nitrates and other minerals in suspension where they can be easily
utilised by the phytoplankton. These conditions are essential to
the photosynthesis of plant species and the respiration of marine
organisms. The abundance of these conditions allows a proliferation
of plankton, the primary produce of the Antarctic Ocean and the
lowest stage of the Antarctic food chain.
Plankton is a group of free-floating organisms which are subdivided
into phytoplankton (plant organisms) and zooplankton (animal organisms).
Their movement is strictly related to sea currents as they can only
move vertically on their own.
Phytoplankton consists of microscopic and largely unicellular algae
and protazoa which bloom under photosynthesis from the sun. Zooplankton
is made up of herbivorous animals which feed on the phytoplankton,
or carnivorous animals which feed on other plankton organisms. Examples
of these creatures are copepods, larval crustaceans, jellyfish,
larval sea urchins, arrow worms and larval fish. The most dominant
group of the zooplankton is krill.
History & Politics
Antarctica, unlike any of the other continents, was believed to
exist long before it was actually discovered. Antarctica is a word
of Greek origin, which means “opposite to the Artic”.
The ancient Greeks, beginning with Pythagoras and further expounded
by Aristotle, believed that the earth was round. This meant that
according to the symmetry of a sphere there had to be a southern
region of land to balance the existing, inhabited northern lands.
They named this undiscovered land Terra Australis Incognita, which
translates as the Unknown Southern Continent.
The beginning of the 16th Century was the beginning of the Golden
Age of Exploration. Most early explorers believed that there did
exist a Great Southern Land, but most early maps show the great
mass joined with the southern tip of Africa, South America, Australia
and New Zealand.
A Portuguese naval voyage led by Bartholomeu Días de Noveas
and Joâo Infante sailed around the southern tip of Africa
and up to Mozambique in 1487. This voyage was followed by Vasco
de Gama in 1497 who sailed south from Europe down the western coast
of Africa, around the Cape of Good Hope and north up the eastern
coast of Africa until he reached India. These explorations proved
that Terra Australis Incognita was not part of the continent of
Africa as was previously supposed.
Similarly, the Portuguese Ferdinand Magellan made an important
discovery while under the patronage of the Spanish Crown to find
an eastern passage to the Indies. He discovered the strait between
South America and the southern land. He named this land Tierra del
Fuego, meaning the Land of Fire due to the sightings of the native
campfires spotted on shore. By discovering this passage, which now
bears his name, he proved that the southern land was in fact separate
from South America, although it was still believed to be connected
to Tierra del Fuego.
In 1577 Englishman Francis Drake, sailing in the Pelican, set out
to make a circumnavigation of the globe. While making a deviation
through the straits he reported sailing around the south of Tierra
del Fuego and discovered the passage which is now named after him.
This proved, that the great southern continent was not continuous
with Tierra del Fuego either.
The end of the 17th and most of the 18th centuries saw several
voyages of exploration south of Tierra del Fuego and many of the
sub-Antarctic and Southern Ocean islands were discovered. The Falklands,
South Georgia and Kerguelen Islands were all once thought to be
northern projections of the southern land, as were Tasmania and
New Zealand, but gradually it was discovered that they were not. |
