The Mont Blanc (French for white mountain) or Monte Bianco (Italian 'White Mountain'), also known as "La Dame Blanche" (French, the white lady) is a mountain in the Alps. With its summit, it is the highest mountain in the Alps and Western Europe, and is ranked 11th in the world in topographic prominence.
The mountain lies between the regions of Aosta Valley, Italy, and Haute-Savoie, France. The location of the summit is on the French-Italian border but Cartographers of France place it within its own boundaries on maps. It is claimed by Italian sources that at a convention between France and Kingdom of Sardinia, in Turin (1861), the border was fixed on the highest point of Mont Blanc, the south east ridge to Monte Bianco di Courmayeur wholly within Italy, and that this was the last official definition of this border. Lately, at the end of his studies of many different maps and with auxiliary of Istituto Cartografico dell’Esercito, Antonio Napolitano, the Italian leader of a mixed commission, claimed exclusive Italian ownership of the summit. The two most famous towns near Mont Blanc are Courmayeur, in Aosta Valley, Italy, and Chamonix, in Haute-Savoie, France — the site of the first Winter Olympics. From Chamonix a cable car ascends the mountain side.
The first recorded ascent of Mont Blanc was on 8 August 1786 by Jacques Balmat and the doctor Michel Paccard. This climb, initiated by Horace-Bénédict de Saussure, who gave a reward for the successful ascent, traditionally marks the start of modern mountaineering. The first woman to reach the summit was Marie Paradis in 1808.
Now the summit is ascended by an average 20,000 mountaineer-tourists each year and could be considered an easy, yet long, ascent for someone who is well trained and used to the altitude. This impression is reinforced by the fact that from l'Aiguille du Midi (where the cable car stops), Mont Blanc seems quite close, being merely higher.
However, every year the Mont Blanc massif takes many victims, and in peak weekends (normally around August) the local rescue service flies an average of 12 missions, mostly directed towards people in trouble on one of the normal routes of the mountain. These are courses that require knowledge of high-altitude mountaineering, a guide (or at least a veteran mountaineer), and proper equipment. It is a long course that includes delicate passages and the hazard of rock slides. Also, at least one night at the refuge is required to get used to the altitude (the summit is almost above sea level); less could lead to altitude sickness and possible death.
The first treaty to define a border in the region is dated 15 May 1796. In this treaty the Sardinian king ceded the territories of Savoie and Nice to the French Republic, and in article 4 of this treaty it says: "The border between the Sardinian kingdom and the departments of the French Republic will be established on a line determined by the most advanced points on the Piedmont side, of the summits, peaks of mountains and other locations subsequently mentioned, as well as the intermediary peaks, knowing: starting from the point where the borders of Faucigny, the Duchy of Aoust and the Valais, to the extremity of the glaciers or the Monts-Maudits: first the peaks or plateaus of the Alps, to the rising edge of the Col-Mayor". This act is even more confusing, because it states that the border should be visible from the town of Chamonix and Courmayeur. The summit is not visible from Courmayeur, because part of the mountain lower down obscures it. Already inaccurate at the time, this treaty is no longer valid, because it was replaced by a later legal act.
This act was signed in Turin on 24 March 1860 by Napoleon III and Victor Emmanuel II of Savoy, and deals with the annexation of Savoie. A demarcation agreement, signed on 7 March 1861, defines the "new border".
One of the prints from the Sarde Atlas, made in 1823 and positions the border exactly on the summital edge of the mountain (and measures it to be high).
The convention of 7 March 1861 recognizes this, through an attached map, taking into consideration the limits of the massif, and drawing the border on the icecap of the Mont Blanc, and therefore makes it both French and Italian. Watershed analysis of modern topographic mapping not only places the main summit on the border, but also suggests that the border should follow a line northwards from the main summit towards Mont Maudit, leaving the south east ridge to Mont Blanc de Courmayeur wholly within Italy.
Despite the fact that the Franco-Italian border was redefined in both 1947 and 1963, the commission, made up of both Italians and French, tactfully ignored the Mont Blanc issue.
Despite this, the observatory was built in 1893. During the cold wave of January 1893 a temperature of was recorded on the Mount Blanc, being the lowest ever recorded there. Levers attached to the ice supported the observatory. This worked to some extent until 1906, when the building started leaning heavily. The movement of the levers corrected the lean slightly, but three years later (two years after Janssen’s death) a crevasse started opening under the observatory and it was abandoned. Eventually the building fell, and only the tower could be saved in extremis.
The summit of Mont Blanc is a thick, perennial ice and snow dome whose thickness varies, so no exact and permanent summit elevation can be determined. But accurate measurements have been made. For a long time its official elevation was . Then in 2002, the IGN and expert surveyors, with the aid of GPS technology, measured it to be .
After the 2003 heatwave in Europe, a team of scientists re-measured the height on 6 and 7 September. The team was made up of the glaciologist Luc Moreau, two surveyors from the GPS Company, three people from the IGN, seven expert surveyors, four mountain guides from Chamonix and Saint-Gervais and four students from various institutes in France. This team noted that the elevation was , and the peak was away from where it had been in 2002.
After these results were published, more than 500 points were measured, to assess the effects of climate change, and the fluctuations in the height of the mountain at different points. From then on the elevation of the mountain has been measured every two years.
The interpretation that the heatwave had caused this fluctuation is disputed, because the heatwave is known not to have significantly affected the glaciers above . The height and position of the summit could have been moved by general glacial forces. At this elevation, the temperatures rarely rise above . During the summer of 2003, the temperature rose to , and even , but this would not have been enough for the ice, which stayed at , to melt.
The summit was measured again in 2005, and the results were published on 16 December 2005. The height was found to be , more than the previous recorded height.
The actual rock summit is at , and is away from the ice-covered summit.
Mont Blanc is one of the most visited tourist destinations in the world, and for this reason, it is threatened. Pro-Mont Blanc (an international collective of associations for the protection of Mont Blanc) published in 2002 the book Le versant noir du mont Blanc (The black hillside of Mont Blanc), which exposes current and future problems in conserving the site.
In 2007, Europe's highest outhouses (two) were transported by helicopter and installed at an elevation of . The dunny-cans are emptied by helicopter. The facilities will service 30,000 skiers annually, and will help prevent the deposit of urine and feces that spread down the mountain face with the spring thaw.