Altitude : 1 913 m
It is impossible to evoke Haute-Savoie without mentioning the largest glacier in France !
True living phenomena, glaciers constantly move. The Mer de Glace is no exception to this rule, with a glacier that advances 90 meters per year, and up to 130 meters in places ! The Mer de Glace of is also a place of scientific experimentation, and many studies (the first dating from 1870) are still carried out here, but it is the magic of the place that makes the Mer de Glace one of the most visited natural sites in the world.
With an area of 40 km² and a length of 7 km, it is the largest glacier in France.
Its width varies from 700 to 1 950 meters and the thickness of the ice is on average 200 meters, sometimes exceeding 400 meters. The Mer de Glace develops over 2 500 vertical meters, between 3 900 and 1 400 meters above sea level.
Three glaciers compose, uniting, the terminal tongue of the Mer de Glace. The Leschaux glacier, whose Grandes Jorasses mark the summit, the Tacul glacier, which unites the Vallée Blanche and the Giant glacier, and finally the Talèfre glacier.
Until 1820, the Mer de Glace was visible from Chamonix.
But each year, it retracts little by little and we can only distinguish one part today. The immense moraines at the edge of the glacier are all traces of this movement.
Unfortunately, global warming is also accelerating this phenomenon.
At the beginning of the 19th century, this immense glacier that changed its name along its route (Vallée Blanche, Tacul, Leschaux ...) descended to the hamlet of the Woods, in the Chamonix valley, from where it is now impossible to have. The ice has indeed retreated a little more than 2 km since 1850 and is hidden behind a huge cliff. After a glacial flood in the 1950s to the 1970s, the melting began in earnest in 1983. Since that date, the Mer de Glace has been declining every year, with rare exceptions. According to LGGE measurements, this decline is not due to a decrease in precipitation, which has changed little over the last 40 years. The amount of snow falling at the source of the glacier (at an altitude of about 4 000 meters) continues to feed it in sufficient quantities. "It's melting that has increased a lot" because "over the last thirty years, summer temperatures have risen 1.5 ° C" on Mont Blanc, said Christian Vincent, glaciologist at LGGE. At 2 200 meters, ice flows have halved in 30 years. In 2008, a capture of EDF (the electricity generating company, which produces energy with the glacier water) was put in the open air by melting ice.
And the glacier front is expected to fall another 1.2 km by 2040, according to LGGE estimates, with a margin of error of plus or minus 200 meters. There will no longer be a glacier in front of the Montenvers station, inaugurated in 1909. A bad omen for the company of Mont Blanc which sends 450 000 people a year on this site to the exceptional point of view whose majority goes down the steps towards the cave, open in winter and summer.
A gondola project is under consideration to allow visitors to go upstream on the glacier, in a place where the ice should still hold more or less 30 years. "People really want to see some ice cream, even if some are disappointed or frightened compared to what they knew 30 years ago," said Mathieu Dechavanne, CEO of the Mont-Blanc company. The ice cave will also be delocalised. And a large center of climate and glaciers study of 400 square meters should emerge near the Montenvers station by 2018-2019.
View 1912
View 2004
MONTENVERS
We no longer present the little Montenvers cogwheel train that takes us to the edge of the equally famous glacier of the Mer de Glace. This excursion was already very popular among the tourists of the nineteenth who then went there on the back of Mules.
The Montenvers railway was the first construction of the valley, especially for tourist purposes. It circulates since 1908.
The site of the Montenvers station also includes a café and a restaurant from which you can enjoy some spectacular views of some of the most prestigious summits of Chamonix: Les Drus (3754 m), Les Grandes Jorasses (4205 m), L'Aiguille du Grépon (3482 m), ... The station is "moored" to the rocky edge which overhangs the Glacier of the Mer de Glace. Near it you can see the museum of alpine fauna and a cave of ice carved by the hand of man. In the bowels of the glacier: an original collection of ice sculptures. The cave must be carved each summer as the glacier advances 70 m each year. In winter, the cave is replaced by a small museum of ice.
In summer, we can make beautiful walks to the plane of the Aiguille for example and down in the valley.
The Montenvers hotel was built in 1880 and still receives guests. It has a rustic charm and combines the authentic qualities of a traditional hideaway with the services of a restaurant and a comfortable hotel.
Official website of the Mer de Glace
https://www.chamonix.net/english/leisure/sightseeing/mer-de-glace
THE CAVE OF THE MER DE GLACE
The ice cave of Chamonix is a cave dug every year in the Mer de Glace since the mid-nineteenth century. The annual renewal is made necessary by the flow of the glacier which is about 90 meters per year. It welcomes 350 000 visitors a year which makes it one of the most visited sites of the department.
In 1862, a foreign entrepreneur proposed to create an artistic cave on the model of the gallery dug for visitors in the lower glacier Grindelwald (de). However, the Chamoniards prefer to carry out the project themselves. After considering the development of the Arveyron vault, they finally opted for a less dangerous solution, the full digging on its right flank of a 25-meter gallery leading to a rotunda. At the entrance, a cottage serves as a dairy to supply tourists and sell souvenirs.
The first cave was dug from April 1863 to the end of June and was immediately a great success. It is then called crystal cave or even crystal palace. At that time, the Mer de Glace descended to the bottom of the valley and was called the Glacier des Bois, the name of the village where it ended and where the cave was. Nevertheless, the glacier was in a phase of rapid retreat and, from 1870 -1871, its peak is in a more rugged area where even the natural arch of the source is no longer formed.
From 1872, the cave was dug at the Bossons glacier under the name of Mont-Blanc cave.
Currently, the ice cave is dug in the Mer de Glace Ice below the panoramic Montenvers station, that is to say nearly 2 kilometers above the first cave. This has been the case since 1946 under the leadership of Geogres Claret. Digging with a pickaxe, its plan stabilizes from 1953 with branched galleries leading to rooms housing furniture and ice sculptures. As the path leading to the cave is narrow and the influx of visitors becomes too great, a cable car is built in 1960 to secure access from the station. With an initial speed of 450 passengers per hour, its insufficient capacity was increased to 700 passengers per hour in 1972 by the removal of seats. It is replaced in 1988 by a gondola lifts that can charge 1200 people per hour. Shortly before, August 19, 1987, the movements of the glacier had caused the fall of the gateway to the cave and about thirty people, causing three deaths and resulting in the decision to place the station downstream on a safer site .
While the ice level was fairly stable during the first 40 years of operation, the glacier began to melt rapidly from 1983, mainly due to a 1.5 ° C increase in summer temperatures. It has since lost a hundred meters thick and made necessary the construction of 420 steps. As it is expected that the movement will continue and that the glacier front will still retreat from 1000 to 1400 meters by 2040, a new location is now sought for the cave.
