The Mer de Glace (, ) is a valley

glacier A glacier (; or ) is a persistent body of dense ice, a form of rock, that is constantly moving downhill under its own weight. A glacier forms where the accumulation of snow exceeds its ablation over many years, often centuries. It acquires ...

located on the northern slopes of the Mont Blanc massif, in the French

Alps The Alps () are some of the highest and most extensive mountain ranges in Europe, stretching approximately across eight Alpine countries (from west to east): Monaco, France, Switzerland, Italy, Liechtenstein, Germany, Austria and Slovenia. ...

. It is 7.5 km long and deep but, when all its tributary glaciers are taken into account, it can be regarded as the longest and largest glacier in France, and the second longest in the Alps after the

Aletsch Glacier The Aletsch Glacier (, ) or Great Aletsch Glacier () is the largest glacier in the Alps. It has a length of about (2014), a volume of (2011), and covers about (2011) in the eastern Bernese Alps in the Switzerland, Swiss canton of Valais. The A ...

Geography

The glacier lies above the

Chamonix Chamonix-Mont-Blanc (; ; (no longer in use)), more commonly known simply as Chamonix (), is a communes of France, commune in the departments of France, department in the regions of France, region in Southeastern France. It was the site of the f ...

valley. The pressure within the ice is known to reach at least 30 atmospheres. The Mer de Glace can be considered as originating at an elevation of , just north of the , where it is formed by the confluence of the and the . The former is fed by the , whilst the latter is, in turn, fed by the Glacier des Périardes, the vast Glacier du Géant and the broad icefields of the . The Glacier du Tacul supplies much more ice than the Glacier de Leschaux. However, if the Mer de Glace is considered in its broadest sense (i.e. from source to tongue), it is a compound valley glacier, gaining ice from snowfields that cover the heights directly north of

Mont Blanc Mont Blanc (, ) is a mountain in the Alps, rising above sea level, located right at the Franco-Italian border. It is the highest mountain in Europe outside the Caucasus Mountains, the second-most prominent mountain in Europe (after Mount E ...

at an altitude of around 4,000 metres. It flows for a total distance of 12 kilometres, covering an area of 32 square kilometres in the central third of the Mont Blanc massif. From the Aiguille du Tacul, the Mer de Glace flows north-north-west between on the east and Trélaporte on the west. It descends below Montenvers, at which point it is approximately 0.5 km wide, and descends to approximately . The glacier was once easily visible from

but has been shrinking backwards, and is now barely visible from below. The surface topography of the Mer de Glace changed very little during the first third of the 20th century, but from 1939 to 2001 the surface of the glacier has lowered an average of 30 cm each year, corresponding to an equivalent loss of 700 million cubic metres of water. Mer de Glace 1

When the tension in the ice increases as the slope increases, the glacier is unable to deform and crevasses appear. These are notably transversal and, when there is intense crevasse activity on the steepest terrain, blocks of

serac A serac () (from Swiss French ''sérac'') is a block or column of glacial ice, often formed by intersecting crevasses on a glacier. Commonly house-sized or larger, they are dangerous to mountaineers, since they may topple with little warning. ...

s appear as the glacier breaks up. Crevasses are of variable depth, depending on their position, and may be as deep as fifty metres. Seracs always form in the same places, namely the steepest sections over which the glacier flows. As crevasses open and seracs tumble downstream, the supply of ice is renewed by the constant flow from upstream. Broad banding patterns, visible on the surface of the Mer de Glace, are known as ogives, or Forbes bands, and result from differences in summer and winter collapse rates of the serac fields. On 24 July 1842, Scottish physicist

James David Forbes James David Forbes (1809–1868) was a Scottish physicist and glaciologist who worked extensively on the conduction of heat and seismology. Forbes was a resident of Edinburgh for most of his life, educated at its University and a professor ...

observed the pattern of light and dark dirt bands on the Mer de Glace from the nearby Aiguille des Grands Charmoz and began to consider whether glaciers flowed in a similar fashion to a sluggish river and with a viscous or plastic manner. In the 18th and 19th centuries, the glacier descended all the way down to the hamlet of Les Bois,: "in 1820 ... sixty yards") where it was known as Glacier des Bois. At that time the river Arveyron emerged from the glacier under a grotto-like vault () and, through the accounts of early writers and explorers, attracted many more visitors, painters and later photographers, for example

J. M. W. Turner Joseph Mallord William Turner (23 April 177519 December 1851), known in his time as William Turner, was an English Romantic painter, printmaker and watercolourist. He is known for his expressive colouring, imaginative landscapes and turbu ...

's ''Source of the Arveron in the Valley of Chamouni Savoy'', 1816. The position of its front end fluctuated over the years but its maximum extent was in the mid-19th century.

Literary and cultural references

Mary Shelley Mary Wollstonecraft Shelley ( , ; ; 30 August 1797 – 1 February 1851) was an English novelist who wrote the Gothic novel ''Frankenstein, Frankenstein; or, The Modern Prometheus'' (1818), which is considered an History of science fiction# ...

's 1818 novel ''

Frankenstein ''Frankenstein; or, The Modern Prometheus'' is an 1818 Gothic novel written by English author Mary Shelley. ''Frankenstein'' tells the story of Victor Frankenstein, a young scientist who creates a Sapience, sapient Frankenstein's monster, crea ...

'' references Mer de Glace during

Victor Frankenstein Victor Frankenstein is a fictional character who first appeared as the titular main protagonist of Mary Shelley's 1818 novel '' Frankenstein; or, The Modern Prometheus''. He is an Italian-born Swiss scientist who, after studying chemical proces ...

's hikes into the Mount Blanc massif. Dr. Frankenstein meets his creation twice during mountaineering on the Mer de Glace. This episode inspired the 1991 opera ''

Mer de glace The Mer de Glace (, ) is a valley glacier located on the northern slopes of the Mont Blanc massif, in the French Alps. It is 7.5 km long and deep but, when all its tributary glaciers are taken into account, it can be regarded as the longe ...

'' by Australian composer Richard Meale to a libretto by his compatriot

David Malouf David George Joseph Malouf (; born 20 March 1934) is an Australian poet, novelist, short story writer, playwright and Libretto, librettist. Elected a Fellow of the Royal Society of Literature in 2008, Malouf has lectured at both the University ...

Notes

Sources

* * New edition reprinted as .

External links

*
Mer de Glace and associated glaciers on French IGN mapping portal

360° photo from surface of Mer de Glace on Google StreetView
{{DEFAULTSORT:Mer De Glace Glaciers of Metropolitan France Landforms of Haute-Savoie Tourist attractions in Haute-Savoie Glaciers of the Alps Landforms of Auvergne-Rhône-Alpes Chamonix

Geography

Literary and cultural references

See also

Notes

Sources

Further reading

External links