Mont Blanc
Mont Blanc is a mountain in the Alps, rising 4,807.3 m, 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, and the 11th most prominent mountain in the world.
The mountain gives its name to its range, the Mont Blanc massif, which straddles parts of France, Italy, and Switzerland. Mont Blanc's summit lies on the watershed line between the valleys of Ferret and Veny in Italy, and the valleys of Montjoie, and Arve in France. Ownership of the summit area has long been disputed between France and Italy.
The Mont Blanc massif is popular for outdoor activities such as hiking, climbing, and trail running and winter sports such as skiing and snowboarding. The most popular climbing route to the summit of Mont Blanc is the Goûter Route, which typically takes two days.
The three towns and their communes which surround Mont Blanc are Courmayeur in Aosta Valley, Italy; and Saint-Gervais-les-Bains and Chamonix in Haute-Savoie, France. The latter town was the site of the first Winter Olympics. A cable car ascends and crosses the mountain range from Courmayeur to Chamonix through the Col du Géant. The Mont Blanc Tunnel, constructed between 1957 and 1965, runs beneath the mountain and is a major transalpine transport route.
Geology
Mont Blanc and adjacent mountains in the massif are predominantly formed from a large intrusion of granite which was forced up through a basement layer of gneiss and mica schists during the Variscan mountain-forming event of the late Palaeozoic period. The summit of Mont Blanc is located at the point of contact of these two rock types. To the southwest, the granite contact is of a more intrusive nature, whereas to the northeast it changes to being more tectonic. The granites are mostly very-coarse grained, ranging in type from microgranites to porphyroid granites. The massif is tilted in a north-westerly direction and was cut by near-vertical recurrent faults lying in a north–south direction during the Variscan orogeny. Further faulting with shear zones subsequently occurred during the later Alpine orogeny. Repeated tectonic phases have caused breakup of the rock in multiple directions and in overlapping planes. Finally, past and current glaciation caused significant sculpting of the landscape into its present-day form.The first systematic account of the minerals of the Mont Blanc area was published in 1873 by Venance Payot. His list, entitled "Statistique minéralogique des environs du Mt-Blanc", catalogued 90 mineral types although it also included those present only as very small components of rocks. If these are excluded, it is known today that at least 68 separate mineral species occur across the wider range of the Mont Blanc massif.
Climate
Located on the watershed between the Rhône and the Po, the massif of Mont Blanc is also situated between the two different climatic regions of the northern and western Alps and that of the southern Alps. Climatic conditions on the Mer de Glace are similar to those found on the northern side of the Swiss Alps.The climate is cold and temperate, and is greatly influenced by altitude. Being the highest part of the Alps, Mont Blanc and surrounding mountains can create their own weather patterns. Temperatures drop as the mountains gain in height, and the summit of Mont Blanc is a permanent ice cap, with temperatures around. The summit is also prone to strong winds and sudden weather changes. Because of its great overall height, a considerable proportion is permanently glaciated or snow-covered and is exposed to extremely cold conditions.
There is, however, significant variation in precipitation with altitude. For example, the village of Chamonix below Mont Blanc is at an elevation of approximately. It receives around of annual precipitation, whilst the Col du Midi, which is at above sea level, receives significantly more, totalling. However, at an even higher altitude, precipitation is considerably less, with only around recorded, despite the latter measurements being taken at the height of.
History
The Mont Blanc was the highest mountain of the Frankish Empire under Charlemagne and the highest mountain of the Holy Roman Empire until 1792.Pierre Martel's 1744 map and sketch of the Chamonix valley contains what is considered the first printed appearance of the name "Mont Blanc".
In 1760, Swiss naturalist Horace-Bénédict de Saussure began to go to Chamonix to observe Mont Blanc. He tried to summit it with the Courmayeur mountain guide Jean-Laurent Jordaney, a native of Pré-Saint-Didier, who accompanied De Saussure since 1774 on the Miage Glacier and Mont Crammont.
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 rewarded the successful ascent, traditionally marks the start of modern mountaineering. The first woman to reach the summit was Marie Paradis in 1808.
Ownership of the summit
At the scale of the Mont Blanc massif, the border between Italy and France passes along most of the main Alpine watershed, from the Aiguille des Glaciers to Mont Dolent, where it reaches the border with Switzerland. However, its precise location near the summits of Mont Blanc and nearby Dôme du Goûter is disputed. Italian officials claim the border follows the watershed, splitting both summits between Italy and France. In contrast, French officials claim the border avoids the two summits, placing them entirely with France. The size of these two disputed areas is approximately on Mont Blanc and on Dôme du Goûter.In 1723, the Duke of Savoy, Victor Amadeus II, acquired the Kingdom of Sardinia. The resulting state of Sardinia was to become preeminent in the Italian unification.
Citing the Treaty of Paris, France claims that the historical border of Savoy and Piedmont diverged from the watershed line, fully encompassing the summit of Mont Blanc within Savoy and consequently, within French territory.
After the Napoleonic Wars, the Congress of Vienna restored the King of Sardinia in Savoy, Nice, and Piedmont, his traditional territories, overruling the 1796 Treaty of Paris. Forty-five years later, after the Second Italian War of Independence, it was replaced by a new 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 Savoy. A demarcation agreement, signed on 7 March 1861, defined the new border. With the formation of Italy, for the first time, Mont Blanc was located on the border of France and Italy, along the old border between the department of Savoy and that of Piedmont, formerly belonging to the Savoyard state.
The 1860 act is still legally valid for both the French and Italian governments. Italy claims, that the border was moved by France in 1865, when surveys carried out by a cartographer of the French army, Captain JJ Mieulet, incorporated the summit into French territory, making the state border deviate from the watershed line, and giving rise to the differences with the maps published in Italy in the same period.
Modern Swiss mapping, published by the Federal Office of Topography, plots a region of disputed territory around the summits of both Mont Blanc and the Dôme du Goûter. One of its interpretations of the French-Italian border places both summits straddling a line running directly along the geographic ridgeline between France and Italy, thus sharing their summits equally between both states. However, a second interpretation places both summits, as well as that of Mont Blanc de Courmayeur, solely within France.
NATO maps take data from the Italian national mapping agency, the Istituto Geografico Militare, which is based upon past treaties in force.
Vallot
Janssen observatory
In 1890, Pierre Janssen, an astronomer and the director of the Meudon astrophysical observatory, considered the construction of an observatory at the summit of Mont Blanc. Gustave Eiffel agreed to take on the project, provided he could build on a rock foundation if found at a depth of less than below the ice. In 1891, the Swiss surveyor Imfeld dug two horizontal tunnels below the ice summit but found nothing solid. Consequently, the Eiffel project was abandoned.Despite this, the observatory was built in 1893. During the cold wave of January 1893, a temperature of was recorded on Mont 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, a crevasse started opening under the observatory. It was abandoned. Eventually the building fell, and only the tower could be saved in extremis.