THE GLACIER

What is the glacier?

A glacier is a mass of ice that is formed on land in consequence of the compaction and recrystallization of snow

The snow turns Snowflakes

Granular snow

Firn

Compact ice

Glacial metamorphism

The transformation of snow into ice is a slow process, which also requires hundreds

of years

The pressure of the snow that accumulates annually determines the compaction of the

underlying material, with the removal of most of the air and increasing the size of the ice

crystals

Part of the air is trapped in the form of bubbles which progressively reduce in size to dissolve in the ice, which assumes a typical

blue color (ice blue)

Snow

Snowcapped

Ice

The world's glaciers

Distribution of ice on the surface of the earth: in dark blue caps, black platforms, clear blue sea ice, mountain glaciers in blue

The world's glaciers

Greenland (7.5%)Ice remaining (0.5%)

Antarctica (92%)

The Glacier of Europe

- 38 % Pyrenees and Mediterranean

-12% Alps

-11% Island

- Svalbard

The limit of permanent snow

The continental glaciers

Also referred to as Norwegian islands

Constitute 99% of all glaciers

Antarctic ice sheet

The largest single mass of ice on Earth

One part covers the

continent, another floats on the sea (glacial platform)

Antarctic ice sheet The ice flows

from the ice caps to a series of

platforms floating on the

sea ice

Beneath the Antarctic ice sheet are mountain ranges

Antarctica seen from satellite

The complete melting of

Antarctic ice would lead to

a sea level rise of about 70 meters

Continental glacier ArcticUnlike Antarctica,

consisting of a perennially ice-

covered continental plateau and

surrounded by the oceans, the Arctic, for most of its length, is formed by a sea (the Arctic Ocean), which occupies the central part of the region

Polar ice Formed from

solidified seawater

The largest ice shelves are located in the Arctic Ocean around the Arctic and around Antarctica

Mountain glaciers Monte Ruitor - Valle d'Aosta

Pizzo Bernina - Svizzera

Aletsch - Svizzera

Gorner – Monte Rosa

Valtellina- Ghiacciao dei Forni

The part of glacier

-Collector basin: area in which there is the accumulation of

snow.The very existence of a glacier depends on the difference between the power supply and ablation, the amount of ice lost by melting or sublimation

THE MOVEMENT

Different velocity

Crevasses and seracs

Alpine glaciers retreat

Reduction of the glacier Present under the big UJA Ciardoney of the Gran Paradiso  • The ice in 1930 and today

The thickness of the Alpine glaciers decreased in a few decades of 14 meters, three of which only the last hot summer 2003.

The glaciers have actually started to decline since 1850 (the end of the so-called "Little Ice Age" that lasted for 250 years), but in recent decades have begun to melt at an unprecedented rate

The "sad" view of the glacier Ciardoney after the hot summer 2003, which has significantly reduced the thickness of the ice. Completely free of residual snow, blackened debris, and it is exposed to strong merger

MEASURES AT THE END OF SUMMER 2012 IN GLACIER Ciardoney: ANOTHER SEASON OF IMPOSING REDRESS

At the end of a summer extraordinarily hot (in third place in Turin from 1753), the entire glacier appeared devoid of residual snow. The findings showed again a considerable loss of mass, equal to a water blade average of 2.16 m, while the front has retreated by 20 m

Les bediéres

10.09.2007: the numerous boulders tumbled down the glacier from the north wall UJA of the Little Ciardoney, a phenomenon more and more important with the deglaciation of the slopes.

The frontal area of the glacier Basei view the 02.09.2003 (left) and the 01.09.2007 (right). You sense the net loss of thickness and the emergence of bedrock in the western (right in photo).

Two large boulders metric sizes precipitate in the right-front in August 2007, obvious effect of deglaciation on the rocky bar above.In the background to the right, the Gran Paradiso and Ciarforon

The glacier Basei viewed from the north, almost completely devoid of snow residua limitata a few benches in the basin at the summit. Clearly visible the morainal century.

The current phase of withdrawal is the continuation of a phase 'hot' already in place or the upward trend in temperature is due to the industrial development started just 150 years ago.

We live in a hot phase "natural", but human activities, in particular the use of fossil fuels that produce carbon dioxide and favor the '' greenhouse effect ', have helped to increase global warming.

The rate of melting of glaciers has tripled since the seventies onwards, and especially after the mid-eighties.

From 1850 onwards, the total volume decreased two-thirds.

Twenty years from the glaciers could be just a memory.

The highest peaks of the Alps, at the end of the twenty-first century, will appear as a barren expanse of gravel and stones.

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Sea of Ice

The sea of Ice is a glacier located on the northen slopes of the Mont Blanc massif, in the Alps.At 7 km long and 200 metres deep, it is the longest glacier in France.