Glaciation
The High Alps has been greatly affected by glacial processes. Many
of the landscape features found owe their origins to ice movement
and deposition of eroded material. Landforms and processes are said
to be affected by their location in a glaciated area, for example,
erosional landforms tend to be located where the ice developed and
moved from, while depositional landforms tend dominate where the ice
flowed to, namely towards the edges of an ice mass.
The High Alpine area on the Franco-Italian frontier was affected by
the Ecrins ice cap during the last Ice Age. Ice flowed south then
west down the Durance valley. Thicker ice created greater erosion,
causing deep ravines and rock steps. Faster flowing ice also created
more erosion. Deposits were carried towards the margins of the glacier,
by ice and meltwater.
The core of the high mountains are thus mainly erosional in form,
whereas many lower valleys and regions towards the edge of the Ecrins
ice mass have extensive areas of glacial and fluvio-glacial deposits.
After the ice age, the area was affected by huge amounts of meltwater,
which flowed towards lower land in the south and west. Melting water
from the Ecrins ice sheet flowed hundreds of miles beyond the High
Alps region towards the south of France. As the ice melted, so the
mountains began to undergo isostatic recovery. This is still taking
place today though the rates of uplift have slowed. Evidence for these
movements are illustrated in the deep ravines and gorges, created
by accelerated river erosion.
The permanent ice and snow that remain in the region today are only
located in the highest and coldest parts of the mountain area. They
are mainly valley, cirque and niche glaciers in form. Recent studies
appear to suggest that most of the glaciers in the Alps are retreating,
this appears to be the case in High Alps.
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