The mountain gives its name to its range, theMont Blanc massif, which straddles parts of France, Italy, and Switzerland. Mont Blanc'ssummit lies on thewatershed line between the valleys ofFerret andVeny inItaly, and the valleys of Montjoie, andArve inFrance. Ownership of the summit area has long been disputed between France and Italy.
Mont Blanc and adjacent mountains in the massif are predominantly formed from a large intrusion ofgranite (termed abatholith) which was forced up through a basement layer ofgneiss andmica schists during theVariscan mountain-forming event of the latePalaeozoic 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 moreintrusive nature, whereas to the northeast it changes to being moretectonic. The granites are mostly very-coarse grained, ranging in type from microgranites toporphyroid 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 laterAlpine 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 thelandscape into its present-day form.[5]
The first systematic account of the minerals of the Mont Blanc area was published in 1873 byVenance 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.[6] 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.[7][8][9][10]
Located on the watershed between theRhône and thePo, 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 theSwiss Alps.[11]: 26
The climate is cold and temperate (Köppen climate classificationCfb),[12] 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 −20 °C (−4 °F). 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.[11]: 24
There is, however, significant variation inprecipitation with altitude. For example, the village of Chamonix below Mont Blanc is at an elevation of approximately 1,030 m (3,380 ft). It receives around 1,020 mm (40 in) of annual precipitation, whilst the Col du Midi, which is at 3,500 m (11,500 ft) above sea level, receives significantly more, totalling 3,100 mm (122 in). However, at an even higher altitude (near the summit of Mont Blanc), precipitation is considerably less, with only around 1,100 mm (43 in) recorded, despite the latter measurements being taken at the height of 4,300 m (14,100 ft).[13]: 23
Pierre Martel's 1744 map and sketch of the Chamonix valley contains what is considered the first printed appearance of the name "Mont Blanc".[14]
In 1760, Swiss naturalistHorace-Bénédict de Saussure began to go toChamonix to observe Mont Blanc.[15] He tried to summit it with theCourmayeur mountain guide Jean-Laurent Jordaney, a native ofPré-Saint-Didier, who accompanied De Saussure since 1774 on the Miage Glacier and Mont Crammont.
The first recorded ascent of Mont Blanc (at the time neither within Italy nor France) was on 8 August 1786 byJacques Balmat and the doctorMichel Paccard. This climb, initiated byHorace-Bénédict de Saussure, who rewarded the successful ascent, traditionally marks the start of modern mountaineering.[16] The first woman to reach the summit wasMarie Paradis in 1808.
At the scale of theMont Blanc massif, the border between Italy and France passes along most of the main Alpine watershed, from theAiguille des Glaciers toMont Dolent, where it reaches the border with Switzerland. However, its precise location near the summits of Mont Blanc and nearbyDôme du Goûter is disputed.[17][18][19] 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 (distinct) disputed areas is approximately 65 hectares (160 acres) on Mont Blanc and ten hectares (25 acres) on Dôme du Goûter.[20]
View of the southern side of Mont Blanc (big summit on the left) fromAiguille Rouge
Citing theTreaty of Paris (1796), 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.[22]
After the Napoleonic Wars, theCongress 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 theSecond Italian War of Independence, it was replaced by a new legal act. Thisact was signed inTurin on 24 March 1860 byNapoleon III andVictor Emmanuel II of Savoy, and deals with the annexation ofSavoy (following the French neutrality for the plebiscites held in Tuscany, Modena, Parma and Romagna to join the Kingdom of Sardinia, against the Pope's will). 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 theSavoyard state.[23]
The 1860 act is still legally valid for both the French and Italian governments.[23] 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.[24][25]
Modern Swiss mapping, published by theFederal Office of Topography, plots a region of disputed territory (statut de territoire contesté) 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 (watershed) between France and Italy, thus sharing their summits equally between both states. However, a second interpretation places both summits, as well as that ofMont Blanc de Courmayeur (although much less clearly in the latter case), solely within France.[20]
1832 Map of the Kingdom of Sardinia showing an administrative border passing through the summit of Mont Blanc. This was the same map annexed to the 1860 treaty to determine the current border between France and Italy.
Captain Mieulet map of 1865 placing the international border south of the watershed[24]
A Sardinian Atlas map of 1869 showing the international border on the watershed[27]
In 1890,Pierre Janssen, anastronomer 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 twelve metres (39 ft) below the ice. In 1891, the Swiss surveyor Imfeld dug two 23-metre (75 ft) horizontal tunnels twelve metres (39 ft) 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 −43 °C (−45 °F) 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 (two years after Janssen's death), a crevasse started opening under the observatory. It was abandoned. Eventually the building fell, and only the tower could be savedin extremis.[28]
In 1946, a drilling project was initiated to carve a tunnel through the mountain. The Mont Blanc tunnel would connectChamonix, France, andCourmayeur, Italy, and become one of the major transalpine transport routes between the two countries. In 1965, the tunnel opened to vehicle traffic with a length of 11,611 metres (7.215 mi).[32]
In 1999, a transport truck caught fire in the tunnel beneath the mountain. In total, 39 people were killed when the fire raged out of control. The tunnel was renovated in the aftermath to increase driver safety. Renovations include computerised detection equipment, extra security bays, a parallel escape shaft, and a fire station in the middle of the tunnel. The escape shafts also have clean air flowing through them via vents. Any people in the security bays now have live video contact to communicate with the control centre. A remote site for cargo safety inspection was created on each side: Aosta in Italy and Passy-Le Fayet in France. Here all trucks are inspected before entering the tunnel. These remote sites are also used asstaging areas to control commercial traffic during peak hours. The renovated tunnel reopened three years after the disaster.[33]
The summit of Mont Blanc is a thick, perennial ice-and-snow dome whose thickness varies. Therefore, no exact and permanent summit elevation can be determined, though accurate measurements have been made on specific dates.Its official elevation was 4,807 m (15,771 ft) for a long time. In 2002, theIGN and expert surveyors, with the aid ofGPS technology, measured it to be 4,807.40 m (15,772 ft 4 in).
View from the Glacier des Bossons, May 2021
After the2003 heatwave in Europe, a team of scientists remeasured 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 theIGN, seven expert surveyors, four mountain guides fromChamonix andSaint-Gervais and four students from various institutes in France. This team noted that the elevation was 4,808.45 m (15,775 ft 9 in), and the peak had shifted to a point 75 cm (30 in) away from where it had been in 2002.
After these results were published, more than 500 points were measured to assess the effects ofclimate change and the mountain's height fluctuations at different points. Since then, the mountain's elevation has been measured every two years.
The summit was measured again in 2005, and the results were published on 16 December 2005. The height was found to be 4,808.75 m (15,776 ft 9 in), 30 cm (12 in) more than the previously recorded height. The rock summit was found to be at 4,792 m (15,722 ft), some 40 m (130 ft) west of the ice-covered summit.[34]
In 2007, the summit was measured at 4,807.9 m (15,774 ft) and in 2009 at 4,807.45 m (15,772 ft).[35]In 2013, the summit was measured at 4,810.02 m (15,781 ft) and in 2015 at 4,808.73 m (15,777 ft).[36]From the summit of Mont Blanc on a clear day, theJura, theVosges, theBlack Forest, and theMassif Central mountain ranges can be seen, as well as the principal summits of the Alps.
Mont Blanc seen from the Rébuffat platform on Aiguille du MidiView from Vallee Blanche of Glacier du Géant andDent du Géant, looking down Glacier du Tacul towards the Mer de Glace, with Aiguille du Moine, les Drus and Aiguille Verte in centre-left
Several classic climbing routes lead to the summit of Mont Blanc:[37][38]
The most popular route is theGoûter Route, also known as theVoie Des Cristalliers or theVoie Royale. Starting fromSaint-Gervais-les-Bains, theTramway du Mont-Blanc (TMB) is taken to get to theGare du Nid d'Aigle. The ascent begins in the direction of theRefuge de Tête Rousse, crossing theGrand Couloir orGoûter Corridor, considered dangerous because of frequent rockfalls, leading to theGoûter Hut for night shelter. The next day the route leads to theDôme du Goûter, past the emergency Vallot cabin and l'Arête des Bosses.
The historic itinerary via theGrands Mulets Hut, or the old normal route on the French side, which is most frequently traversed in winter by ski, or in summer to descend to Chamonix.
The normal Italian itinerary is calledLa route des Aiguilles Grises. After crossing theMiage Glacier, climbers spend the night at theGonella refuge. The next day, one proceeds through the Col des Aiguilles Grises and the Dôme du Goûter, concluding at L'arête des Bosses (Bosses ridge).
The Miage – Bionnassay – Mont Blanc crossing is usually done in three days. It has been described asa truly magical expedition of ice and snow arêtes at great altitude.[39]: 199 The route begins from Contamines-Montjoie, with the night spent in theConscrits Hut. The following day, the Dômes de Miages is crossed and the night is spent at the Durier cabin. The third day proceeds overl'Aiguille de Bionnassay and the Dôme du Goûter, finally reaching the summit of Mont Blanc via the Bosses ridge.
Aerial view of Mont Blanc from 9,000 meters above sea level
Nowadays, the summit is ascended by an average of 20,000 mountaineer tourists each year. It could be considered a technically easy yet arduous ascent for someone well-trained and acclimatised to the altitude. From l'Aiguille du Midi (where the cable car stops), Mont Blanc seems quite close, being 1,000 m (3,300 ft) higher. But while the peak looks deceptively close, the La Voie des 3 Monts route (known to be more technical and challenging than other more commonly used routes) requires more ascent over two other 4,000 m (13,000 ft) mountains,Mont Blanc du Tacul andMont Maudit, before the final section of the climb is reached. The last 1,000 m (3,300 ft) push to the summit is undertaken.
Each year climbing deaths occur on Mont Blanc. On the busiest weekends, normally around August, the local rescue service performs an average of 12 missions, mostly directed to aid people in trouble on one of the normal routes of the mountain. Some routes require knowledge of high-altitude mountaineering and a guide (or at least an experienced mountaineer), and all require proper equipment. All routes are long and arduous, involving delicate passages and the hazard of rockfall or avalanche. Climbers may also sufferaltitude sickness, occasionally life-threatening, particularly if they are not properlyacclimatised.[40][41]
A 1994 estimate suggests there had been 6,000 to 8,000 alpinist fatalities in total, more than on any other mountain.[39]: 208 These numbers exclude the fatalities ofAir India Flight 245 andAir India Flight 101, two planes that crashed into Mont Blanc. Despiteunsubstantiated claims recurring in media that "some estimates put the fatality rate at an average of 100 hikers a year",[42] actual reported annual numbers at least since the 1990s are between 10 and 20: in 2017, fourteen people died out of 20,000 summit attempts, and two remained missing; with 15 in 2018 as of August.[43]
A French study on the especially risky "Goûter couloir, on the normal route on Mont Blanc" and necessary rescue operations found that, between 1990 and 2011, there were 74 deaths "between the Tête Rousse refuge (3,187 m) and the Goûter refuge (3,830 m)". There were 17 more in 2012–15, none in 2016, and 11 in 2017.[44]
The recent temperature rises and heatwaves, such as those of the summers of 2015 and 2018, have significantly impacted many climbing routes across the Alps, including those on Mont Blanc. For example, in 2015, the Grand Mulets route, previously popular in the 20th century, was blocked by virtually impenetrable crevasse fields, and theGoûter Hut was closed by municipal decree for some days because of a very high rockfall danger, with some stranded climbers evacuated by helicopter.[45]
In 2016 acrevasse opened at high altitude, also indicating previously unobserved glacial movements. The new crevasse forms an obstacle to be scaled by climbing parties on the final part of the itinerary to the top shared by the popularGoûter Route and the Grand Mulets Route.[46][47]
1990:TheSwiss Pierre-André Gobet, leaving fromChamonix, completed the ascent and descent in 5 hours, 10 minutes and 14 seconds.
30 May 2003 (2003-05-30):Stéphane Brosse andPierre Gignoux tried to beat the record by ski-walking. They went up in 4 hours and 7 minutes and came back down in 1 hour and 8 minutes. In total, they did the ascent and descent in 5 hours and 15 minutes.
13 August 2003 (2003-08-13):Seven French paraglider pilots landed on the summit. They reached a peak altitude of 5,200 m (17,100 ft), thanks to the hot weather conditions, which provided strong hot air currents. Five had left from Planpraz, one fromRochebrune atMegève and the last one fromSamoëns.
8 June 2007 (2007-06-08):Danish artistMarco Evaristti draped the peak of Mont Blanc with red fabric, along with a 20 ft (6.1 m) pole with a flag reading "Pink State". He had been arrested and detained earlier on 6 June for attempting to paint a pass leading up to the summit red. He aimed to raise awareness of environmental degradation.[50]
13 September 2007 (2007-09-13):A group of 20 people set up a hot tub at the summit.[51]
19 August 2012 (2012-08-19):Fifty paraglider pilots landed on the summit, beating the previous record of seven top landing pilots, set in 2003. This included the second-ever tandem landing on the summit.[52]
11 July 2013:Kilian Jornet beat the fastest overall time for ascent and descent with 4 hours, 57 minutes and 40 seconds.[53][54]
21 June 2018:Emelie Forsberg set a women's fastest known time up and down from Chamonix with 7 hours 53 minutes and 12 seconds, improving her previous record of 8 hours 10 minutes from 2013.[55]
17 June 2023:Hillary Gerardi set a new women's fastest known time with 7 hours, 27 minutes and 39 seconds, taking a longer but safer route via the Arête Nord due to serac fall.[56]
In July 2014, an American entrepreneur and travellerPatrick Sweeney attempted to break the record with his nine-year-old son and 11-year-old daughter. They were caught inan avalanche, escaped death and decided not to pursue their attempt.[57][58]
In August 2014, an unknownAustrian climber with his 5-year-old son were intercepted bymountain gendarmes at 3,200 m (10,500 ft) and forced to turn back.[59]
On 5 August 2017, 9-year-oldHungarian twins and their mother were rescued from 3,800 m (12,500 ft) by helicopter while their father and family friend continued their summit attempt.[60]
La Terre, son visage, is a documentary by Jean-Luc Prévost and published by Édition Société national de télévision française, released in 1984. It is part of theHaroun Tazieff raconte sa terre, vol. 1 series. In it he talks about the west–east crossing of Mont Blanc.
La Roue (The Wheel, 1923) is a 273-minute film byAbel Gance depicting rail operations, workers, and families in south-eastern France, including the Mont Blanc area.
The Tripods (1985/86) BBC TV adapatation of the first two novels in John Christopher’s Tripods trilogy (The White Mountains,The City of Gold and Lead), which ran for 25 episodes over two seasons. The main characters are journeying to Mont Blanc where a group of humans free of the Tripods’ subjugation live.
The Mont Blanc massif is being put forward as a potentialWorld Heritage Site because of its uniqueness and cultural importance considered the birthplace and symbol of modern mountaineering.[61] It would require the three governments of Italy, France and Switzerland to requestUNESCO for it to be listed.[62]
Mont Blanc is one of the most visited tourist destinations in the world. For this reason, some view it as threatened.[63] Pro-Mont Blanc (an international collective of associations for the protection of Mont Blanc) published in 2002 the bookLe versant noir du mont Blanc (The black hillside of Mont Blanc), which exposes current and future problems in conserving the site.[64]
In 2007, Europe's two highest toilets (at 4,260 metres, 13,976 feet) were taken by helicopter to the top of Mont Blanc. They are also serviced by helicopter. They will serve 30,000 skiers and hikers annually, helping to alleviate the discharge of urine and faeces that spreads down the mountain face with the spring thaw.[65]
Global warming has begun to melt glaciers and cause avalanches on Mont Blanc, creating more dangerous climbing conditions.[66]
^AlthoughMount Elbrus is normally considered the tallest mountain in continental Europe, the latter continent is part of theEurasian land mass, which culminates at Mount Everest (highest col between Mont Blanc and Mount Everest: 113 m[1]Archived 21 February 2016 at theWayback Machine; highest col between Mount Elbrus and Mount Everest: 901 m[2]Archived 21 February 2016 at theWayback Machine).
^the prominence of 4,696 m for Mont Blanc is taken from the "Ultras Project" (peaklist.orgArchived 9 January 2019 at theWayback Machine), "List compiled 2004 by Petter Bjørstad, Jonathan de Ferranti, Eberhard Jurgalski, Vasja Kavcic and Aaron Maizlish".See alsolist of Alpine peaks by prominence.
^Reynaud, Louis (1993). Williams, Richard S.; Ferrigno, Jane G. (eds.)."The French Alps"(PDF).Satellite Image Atlas of Glaciers of the World. Professional Paper 1386. U.S.Geological Survey.Archived(PDF) from the original on 23 April 2021. Retrieved18 January 2016.
^"Monte Bianco, la Francia "invade" il confine italiano: si rischia il caso diplomatico" [Mont Blanc, France "invades" the Italian border: diplomatic case at risk].La Repubblica (in Italian). 23 July 2019.Archived from the original on 30 November 2021. Retrieved25 January 2022.Un'ordinanza francese 'invade' il territorio del Monte Bianco che l'Italia considera come proprio e il caso rischia di riaprire il contenzioso, mai risolto, sui confini tra i due Paesi ed avere complessi sviluppi giudiziari. [A French order 'invades' the Mont Blanc territory that Italy considers as its own and the case risks reopening the dispute, never resolved, of the borders between the two countries with complex judicial developments.]
^"Monte Bianco, cresce la tensione tra Italia e Francia: Macron vuole la vetta" [Mont Blanc, the tension between Italy and France is growing: Macron wants the summit].La Repubblica (in Italian). 21 October 2020.Archived from the original on 25 January 2022. Retrieved25 January 2022.L'ultimo motivo di attrito: due leggi a favore della biodiversità violano la sovranità italiana sul proprio territorio. Di Maio protesta formalmente: "Forte disappunto" [The last reason for friction: two laws in favor of biodiversity violate Italian sovereignty over its territory. Di Maio formally protests: "Strong disappointment"]
^"Parliamentary questions: Answer given by Ms Johansson on behalf of the European Commission". European Parliament. 3 March 2021.Archived from the original on 25 January 2022. Retrieved25 January 2022.The Commission is aware of the ongoing dispute between Italy and France regarding their common border in the Mont Blanc area, particularly in the area of the Torino Hut, and would welcome a swift — and for both parties satisfactory — settlement.
^"Scontro Italia-Francia sul Monte Bianco" [Italy-France clash on Mont Blanc].Swissinfo (in Italian). 4 October 2019.Archived from the original on 25 January 2022. Retrieved25 January 2022.La cartografia ufficiale italiana, in uso alle Forze Nato e riconosciuta a livello internazionale, si basa sulla Convenzione del 1861... [The official Italian cartography, in use by the NATO forces and internationally recognized, is based on the 1861 Convention...]
^The map is based on measurements taken in 1856 before the convention of 7 March 1861 and is identical to the map attached to the Treaty of Turin. SeeIGN
^abHelmut Dumler and Willi P. Burkhardt,The High Mountains of the Alps, London: Diadem, 1994
^Muza, SR; Fulco, CS; Cymerman, A (2004)."Altitude Acclimatization Guide".US Army Research Inst. Of Environmental Medicine Thermal and Mountain Medicine Division Technical Report (USARIEM-TN-04-05). Archived from the original on 23 April 2009. Retrieved5 March 2009.
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