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A glacier is a river of water in solid
state, a mass of ice and snow in continuous movement more or
less fast, according to its slope and volume.
It is formed by the accumulation of ice and snow in the upper
basins and it is commonly called snowdrift.
The snow, with the hexagonal perfection of its flakes, that
in great amounts covers the high mountainous regions, goes through
a series of changes that transform it into glacier ice. The
snowdrifts turned into ice descend slowly due to the plasticity
of their mass and the great pressures that the high zones exert
on the lower ones along the valleys, giving rise to glacial
tongues of shining blue whiteness.
There are two types of glaciations in Patagonia: the first one
is the so-called Continental Ice, a great ice cap that covers
the central part of the Andean range and sends its outflows
to the Pacific Ocean and to the great Patagonian lakes; the
second kind are the Peripheral Glaciers that in several hundreds
develop in the highest part of the mountain chains.
The Patagonian Continental Ice stretches between parallels 46º
and 51º 30´ of south latitude and between the Pacific
Ocean and the great Austral Patagonian lakes. Its outflows are
shown in huge masses of glacial ice that form the well-known
glaciers:
MARCONI, VIEDMA, UPSALA, AGASSIZ, BOLADO, ONELLI, SENA, PEINETA,
SPEGAZZINI, MAYO, AMEGHINO, PERITO MORENO, and FRIAS.
Each of them has a surface of several hundreds of square kilometres.
The Upsala has 595 km2, the Viedma, 575 km2 and the Moreno,
the smallest one, 195 km2.
The huge glacial masses on their way give rise to dams in the
valleys and hollows of their borders, forming lakes that fill
with floes, which are masses of ice of different shapes and
sizes, extremely irregular and variable, but generally of colossal
dimensions.
Some of the floes may have a diameter of more than a hundred
metres and may be more than 30 metres high.
As a rule, they have a long submerged base which, as days go
by, is eaten away by the water below the surface, thus making
them lose their stability, turn around and even get completely
overturned.
Suddenly the huge mass breaks up into fragments that fall into
the water with a tremendous noise and turn over so that the
base of the floe becomes the top, with gigantic tips, a scene
which creates an extraordinary, dazzling, wonderful sight which
will be hard to forget.
Bibliographic source: Glaciological aspects
of the zone of Patagonian Continental Ice by Mario Bertone.
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