Around both poles
of the earth the polar regions extend.
The polar caps are limited by the
Arctic Circles, to 66º 33 ' of
North latitude, and Antarctic, to
the same latitude in the South hemisphere.
Both regions are mostly covered with
ice, product of the winter snow accumulation
that does not reach to be fused by
the solar light during the summer.
The great masses of ice, called icebergs,
are characteristic of the polar seas,
blocks that to be located on the coasts
fall off and begun to float to the
drift, until disappear confused with
the water of the sea.
The polar climate
In the poles, by
the Earth position respect to the
Sun, the rays lower oblique. Consequently,
it does not manage to be totally absorbed
by the ground, and a great percentage
of the heat is rejected by reflection.
The temperatures are very rigorous;
in many sites, not even reaching values
over zero in summer. The extreme marks
that have been registered are of -126
F in the Antarctic, and -58 F in the
is that in both areas, as is more
near to the poles, winters are darker
and summers most luminous. In the
polar zones, summer and winter last
six months, and during the coldest
station the sun does not show in the
The life in the
Arctic and the Antarctic
In its continental
sector, the Arctic includes the northern
ends of North America (Alaska, Canada
and Greenland), Europe (Scandinavian
countries) and Asia (Russia).
The fact that the
colds are not so extreme in the Arctic
region must to the fact that most
of it, unlike the Antarctic, is occupied
by the sea. The oceanic mass of water
absorbs the heat better during the
The most known animal
in this biome is the polar bear, the
greater living carnivore. It can weight
even 1760 pounds, and it mainly feeds
on seals and fish. When it is not
able to catch them, it eats mosses
Unlike the Arctic,
the Antarctic is a true continent,
of about 14.000.000 of km2. Hardly
7,600 km2 of that extension are free
of ice; the glacial cap has in some
sites up to 4 km of thickness.
The vegetal life
is reduced to lichens and mosses.
Nevertheless, there are two species
of plants with flowers. Both grow
in the Antarctic Peninsula, the end
closest to South America, warmer and
humid than the rest of the territory.
The lichens arise in the naked surfaces
of rocks. They are very resistant
to the cold and the drought; they
obtain water of the fused snow, and
nutrients of excrements of birds,
transported by the wind.
Because of the lack
of vegetation, it does not exist terrestrial
mammalian. The terrestrial animal
of greater size measures 0.5 cm: it
is a fly without wings, that in summer
lives in the fresh water ponds. There
are also tiny crustaceans, along with
protozoon and other simple living
The penguins are
nonflying birds that nest and live
in great colonies near the coasts.
They are clumsy in earth, but very
capable swimmers and divers. The emperor
penguin is the most beautiful specie
and of greater size. Other typical
birds of the region are the albatrosses
and petreles. They have long and narrow
wings that allows them to glide, in
a continuous flight on the surface
of the sea.
They only descend
to the water to feed on fish and calamaries
or to rest. In mainland they settle
on rocky protuberances, but only during
the period of reproduction.
of the cold and the long polar
night, species can be found in
these regions, like polar bears,
seals whales, penguin and others.
Six species of seals
inhabit the region; in XIX century
they have been drastically reduced
by huntings, untied to take advantage
of his skin and fat. Another typical
settler of Antarctic waters is the
whale, equally threatened by the indiscriminate
capture with industrial aims.
The fishing of some
of its species has been prohibited,
like the blue whale. For others it
is only allowed, as in the case of
the seals, with scientific aims. In
the Antarctic marine bottoms there
are great amount of fish, that feed
themselves mainly on kril. It is called
thus to zooplancton, formed by several
species of marine crustaceans.
The kril plays an
important role in the food web, reason
why the excess of its fishing could
introduce dangerous modifications
in the marine biomes.
The Antarctic continent
is of great ecological value, because
it participates in the regulation
of the climate in all the planet,
and in the flow of the ocean currents.
The risk alteration of an ecosystem
of such importance impelled, from
the Antarctic Treaty of 1959, the
action of many groups of scientists,
ecologists and common citizens that
proposes to declare the Antarctica
ecological reserve of the humanity.
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