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85-593: The relatively isolated but easily accessible summit of the Tour Ronde has a reputation for providing mountaineers with one of the finest viewpoints within the Mont Blanc range , and offers an ideal place for observing the sun rising on Mont Blanc itself. To the north it offers extensive views over the wide and heavily crevassed Géant Glacier ( French : Glacier du Géant ) and the Vallée Blanche towards

170-749: A body on the Glacier du Talèfre, close to the Couvercle Hut. It was identified as that of a young Chamonix guide who had been caught in a winter storm during a solo ascent of the Nant Blanc face of the Aiguille Verte in 1982 and was assumed to have fallen into a crevasse. In 2013, a box of valuable gemstones was found by a climber on the Bossons Glacier. It had re-emerged, having been carried 3,048 metres (10,000 ft) downhill from

255-483: A code of practice put in place which requires an annual declaration of all finds to be made. It also gives a right for the Chamonix crystal museum (Musée des Cristaux) to have first option to acquire specimens of significance for its collections. To further protect the scientific value of material collected, all specimens offered for sale must be labelled with details of where they were found. The crystal museum opened to

340-477: A distance of up to 800 metres. An EU Interreg –funded project was established to undertake research. Known as PERMAdataROC, its aims were to "improve our understanding of the relationship between permafrost degradation and slope instabilities by quantifying the occurrence and magnitude of rock falls from high-mountain rock walls". Seven sites in the Mont Blanc Massif were selected, with the east face of

425-709: A meagre harvest of rye and oats . Some farmers in the valley of Chamonix joined their counterparts from the neighbouring valleys of Maurienne , Beaufortain and Tarentaise and crossed the Alps into southern Germany, Austria and northern Italy to sell their products and bring back goods for sale in local markets. In 1741, the Chamouny valley and its glaciers on the north side of the massif were discovered and written about by two aristocratic travelling Englishmen, named William Windham and Richard Pococke . The descriptions of their exploits were published across Europe, bringing

510-579: A number of articles on the flora around the Mont Blanc area, including a list of the flowering plants, ferns mosses and lichens found at les Grands Mulets and elsewhere in the massif around Chamonix and the Aosta Valley. High up in the middle of the Glacier de Talèfre, completely surrounded by ice, and due south of Les Droites, lies a large triangular region of steep mountainside containing an unusual mixture of high-alpine vegetation. Known as

595-553: A significant impact on the environment and on human activity. In 1892, a large body of water which had accumulated under the surface of the Tête Rousse Glacier , burst suddenly on the night of 11 July. It released 200,000 cubic metres (7,100,000 cu ft) of water and ice which flowed down the mountainside, killing 175 people in Saint-Gervais. The recent rediscovery of a further build-up of water deep within

680-700: A small population of albino marmots within Val Ferret). Eurasian lynx have been reintroduced into the French Alps and, although present around the Mont Blanc massif, are extremely unlikely to be encountered. Over 80 different bird species have been recorded on the Italian side of the massif from within Val Ferret, including 63 nesting species and nine regional or national rarities. The following birds have been recorded in different habitats right across

765-585: A study was launched to monitor potentially unstable rock faces and to assess changes over time. Previous techniques had used aerial photography and digital elevation modelling (DEM) , but were deemed not to be sufficiently accurate to monitor change because of the vertical viewpoint and shadowing effects, plus the general coarse nature of their results. By 2005 the newly-evolving technique of Light Detection and Ranging, known as LiDAR , permitted highly detailed laser scanning of high mountain rock faces, measuring many thousands of separate points every second, and from

850-407: A wide range of spatial and temporal scales, from minutes to years and from dislodging mineral grains to fracturing boulders . It is most pronounced in high- altitude and high-latitude areas and is especially associated with alpine , periglacial , subpolar maritime , and polar climates , but may occur anywhere at sub- freezing temperatures (between −3 and −8 °C (27 and 18 °F)) if water

935-436: A year die across its mountains and, occasionally, bodies have been lost and entombed in its glaciers for decades. Access into the mountains is facilitated by cable cars , mountain railways and mountain huts which offer overnight refuge to climbers and skiers. The long-distance Tour du Mont Blanc hiking trail circumnavigates the whole massif in an 11-day trek of 170 kilometres (110 mi). The Mont Blanc Tunnel connects

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1020-417: Is able to displace or fracture rock. At a temperature of -22 °C, ice growth is known to be able to generate pressures of up to 207 MPa , more than enough to fracture any rock. For frost weathering to occur by volumetric expansion, the rock must have almost no air that can be compressed to compensate for the expansion of ice, which means it has to be water-saturated and frozen quickly from all sides so that

1105-447: Is also used for an annual mountain ultramarathon , with top competitors expected to complete the whole route in less than 21 hours. The main mountain passes, or cols , that connect different valleys and towns around the Mont Blanc massif are: The Mont Blanc massif includes eleven independent and six subsidiary summits over 4,000 metres (13,123 ft) in height. These (including Mont Blanc) are shared between Italy and France only,

1190-581: Is distributed fairly evenly over all months of the year, and mostly originates from a westerly airflow. There is, however, significant variation in precipitation with altitude. For example, Chamonix has an elevation of approximately 1,030 metres (3,380 ft) and receives around 1,020 mm (40 in) of annual precipitation, whilst the Col du Midi, which is at 3,500 metres (11,500 ft) above sea level, receives significantly more, totalling 3,100 mm (122 in). However, at an even higher altitude (near to

1275-404: Is further influenced by the different aspects of the faces, by the geology, and by the influence of man on the lower and middle slopes where forest clearance has created open grassland . The native forest habitats are essential for the survival of many species, with the key conifer species including larch, pine, stone pine and red pine. Over a thousand plant species have been recorded across

1360-439: Is known today that at least 68 separate mineral species occur across the whole range of the Mont Blanc massif. In order to preserve the mineralogical heritage of Mont Blanc, in 2008 the commune of Chamonix banned all mineral-hunting activities and collection of specimens without a prior permit being issued by the mayor 's office. Use of explosives , heavy machinery or helicopters for removing material were also banned, and

1445-505: Is located at 2,173 m (7,129 ft) above sea level, and is the highest botanical garden in Europe. It contains around 800 plant species and covers an area of 7,000 square metres (75,000 sq ft). It was originally created in 1987 just as a tourist attraction but, with the subsequent designation of the adjacent Pavillon du Mont Frety as a protected area, it has since increased in scientific importance. It can be reached either from

1530-401: Is located has been occupied by humans for at least 70,000 years, although, as now—and because of the great height and glaciated nature of the mountains—only the lower parts of the valleys around its perimeter would have been inhabited or used as routes of communication. The Romans, who occupied the region 2,000 years ago, used the main valleys around the massif for military purposes. They gave

1615-552: Is often the most important weathering process for exposed rock in many areas. Similar processes can act on asphalt pavements, contributing to various forms of cracking and other distresses, which, when combined with traffic and the intrusion of water, accelerate rutting, the formation of potholes , and other forms of pavement roughness. The traditional explanation for frost weathering was volumetric expansion of freezing water. When water freezes to ice , its volume increases by nine percent. Under specific circumstances, this expansion

1700-411: Is present. Certain frost-susceptible soils expand or heave upon freezing as a result of water migrating via capillary action to grow ice lenses near the freezing front. This same phenomenon occurs within pore spaces of rocks. The ice accumulations grow larger as they attract liquid water from the surrounding pores. The ice crystal growth weakens the rocks which, in time, break up. It is caused by

1785-401: Is significantly less than that in either Courmayeur or Chamonix. The massif contains a very rich variety of biodiversity as a result of the huge height range and different habitats found between the valleys and the highest summits. Mild temperatures occur at altitudes between 600 and 1,000 metres (2,000 and 3,300 ft), whereas arctic conditions occur from 2,500 metres (8,200 ft) up to

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1870-494: The Aiguille d'Argentière , the Aiguille du Chardonnet and the Aiguille du Tour , before dropping down to the Col de Balme. The Swiss – Italian border runs southwest from Mont Dolent, down to the twin passes of Col Ferret. The massif contains 11 main summits over 4,000 metres (13,123 ft) in altitude, as well as numerous subsidiary points above this height. Crowning the massif is Mont Blanc (4,808 metres (15,774 ft)),

1955-687: The Aiguille du Midi , whilst looking westwards it provides very extensive views towards Mont Maudit and the full sweep of the Brenva Face of Mont Blanc and the Peuterey Ridge. Writing about the first ascensionist's impression of the view from the summit of the Tour Ronde, one author quoted Douglas Freshfield in volume 6 of The Alpine Journal (1874), thus: He wrote of this at the time that no other view had left upon his mind "a recollection of such overpowering magnificence". The Tour Ronde can be most easily reached within about 1.5 hours from

2040-568: The Alps , located mostly in France and Italy , but also straddling Switzerland at its northeastern end. It contains eleven major independent summits, each over 4,000 metres (13,123 ft) in height. It is named after Mont Blanc (4,808 metres (15,774 ft)), the highest point in western Europe and the European Union . Because of its considerable overall altitude, a large proportion of

2125-559: The Grandes Jorasses , Rochefort Ridge , Dent du Géant , Mont Maudit , Mont Blanc and its western satellite, the Aiguille de Bionnassay . From here the border turns southwards over the Dômes de Miage and Aiguille de Tré la Tête before dropping down to the Col de la Seigne. North of Mont Dolent the border between France and Switzerland meanders roughly north-northwestwards along a ridge-line of slightly lower peaks, including

2210-508: The Jardin de Talèfre , its name derives from the rich assemblage of plants which occur at great altitude there (between 2,650 and 3,000 m (8,690 and 9,840 ft)). Described as "one of the loftiest patches of vegetation in Europe upon an islet of rock in the midst of a wilderness of snow and ice", it is higher than the adjacent ground by tens of metres and, as a result, was spared glacial scouring and subsequent loss of its vegetation during

2295-1030: The Little Ice Age (between 1300 and 1850). Nevertheless, it would at that time still have been surrounded by ice on all three sides, as evidenced by the three glacial moraines found there today. Species recorded there include: Achillea nana ; Alchemilla pentaphylla ; Arenaria biflora  [ de ] ; Arenaria serpyllifolia ; Cardamine alpina ; Draba frigida ; Empetrum nigrum ; Epilobium alpinum ; Helictotrichon versicolor  [ pl ] ; Homogyne alpina ; Jacobaea incana ; Juncus trifidus ; Kalmia procumbens ; Poa laxa  [ pl ] ; Potentilla frigida  [ de ] ; Ranunculus glacialis ; Ranunculus pyrenaeus  [ de ] ; Saxifraga aspera ; Saxifraga bryoides ; Saxifraga oppositifolia ; Sedum alpestre  [ es ] ; Sibbaldia procumbens and Trifolium alpinum . The Saussurea Alpine Botanical Garden above Courmayeur

2380-777: The Torino Hut near Pointe Helbronner , where mountaineers spend the night before leaving, usually well before dawn, to ascend the summit early the next day. Alternate and longer routes can be made from the Refuge des Cosmiques at the Col du Midi via a passage across the head of the Vallee Blanche and the Géant Glacier (or from Chamonix via the Aiguille du Midi and the Vallée Blanche Aerial Tramway ). Pointe Helbronner can also be reached from

2465-415: The freeze-thaw cycle of water, with maximum occurrence during warm summers. In 2015 a huge rockfall on the Tour Ronde's east face was captured on film by climbers, demonstrating that instability in this mountain area remains at a significant level. Mont Blanc massif The Mont Blanc massif ( French : Massif du Mont-Blanc ; Italian : Massiccio del Monte Bianco ) is a mountain range in

2550-586: The massif is covered by glaciers , which include the Mer de Glace and the Miage Glacier  – the longest glaciers in France and Italy, respectively. The massif forms a watershed between the vast catchments of the rivers Rhône and Po , and a tripoint between France, Italy and Switzerland; it also marks the border between two climate regions by separating the northern and western Alps from

2635-739: The massif lies mostly within Italy and is bounded by the Val Veny and Val Ferret whose watercourses meet just above Courmayeur . From Courmayeur these waters flow southwards as the Dora Baltea towards Aosta , eventually joining the Po. However, the extreme western end of the southern side of the massif does lie within France and is bounded by the Vallée des Glaciers (which connects to the Val Veny over

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2720-586: The silver age of alpinism (1865–82) that the majority of the main summits of the massif were first attained. Members of the England-based Alpine Club were instrumental in many of the first ascents, usually accompanied by guides from Chamonix or Courmayeur, such as Michel Croz , Michel Payot and Émile Rey , as well as the Swiss guide, Christian Almer . Across the massif there are now more than two thousand different mountaineering routes to

2805-441: The 1980s, held to be the predominant process behind frost weathering. This view was challenged in 1985 and 1986 publications by Walder and Hallet. Nowadays researchers such as Matsuoka and Murton consider the "conditions necessary for frost weathering by volumetric expansion" as unusual. However the bulk of recent literature demonstrates that that ice segregation is capable of providing quantitative models for common phenomena while

2890-593: The 5th century AD, they had left completely. The areas left behind were occupied in the western part by the Burgundian tribes from what is today France, whilst the Alemanni tribes from Germany moved into eastern parts, resulting in the linguistic divide found today across the Alps. For many centuries thereafter, the settlements around the Mont Blanc massif comprised a rural population of peasant mountain farmers, living off animal husbandry , supplemented with

2975-433: The Chamonix valley by Charles Albert of Sardinia for reconstructing the towns of Sallanches and Cluses , both of which had at that time just been destroyed by fires. The massif has been an important source of mineral specimens for crystal -hunters for over 250 years. The mountaineer and explorer, Edward Whymper , noted that the basin of the Glacier de Talèfre was "considered good hunting-ground for crystals", and that

3060-455: The French town of Chamonix on the northern side with the Italian town of Courmayeur in the south. The high mountains have provided many opportunities for scientific research, including neutrino measurements within the tunnel and impact of climate change on its highest slopes. Recent rises in average temperatures have led to significant glacial retreat across the massif and an awareness of

3145-560: The Italian side on foot or via cablecar from Courmayeur . Other even longer start or finish points include the Requin Hut above Montenvers, reached by a long but impressive glacier trek. The mountain provides many routes of ascent, and of varying difficulty and danger, as well as opportunities for possible new routes of mixed climbing. Classic mountaineering routes on the Tour Ronde include: Other new mixed climbing ascents routes have also been achieved in recent years although, because of

3230-549: The Miage Glacier and the Brenva Glacier, are very heavily covered in rock debris. The massif is itself defined by broad valleys which formed along fault lines and which have subsequently been shaped by ice during the last glacial period of the ice age. During the mid-19th century the granite of the Mont Blanc massif was an important source of stone for buildings; one hundred Italian stonemasons were brought to

3315-657: The Miage Glacier is Italy's longest glacier and also the largest debris-covered glacier in Europe. Other large glaciers include the Argentière Glacier (9 km (5.6 mi)), the Saleina Glacier (6 km (3.7 mi)), Trient Glacier (4 km (2.5 mi)), the Bossons Glacier ( c. 4 km (2.5 mi)) and the Brenva Glacier. Whilst these glaciers appear to show similar fluctuations in length, research shows that each glacier of

3400-599: The Mont Blanc massif has its own individual and distinctive response time to changes in snowfall and climate. The Bossons Glacier is known to respond first, then the Argentière and the Trient Glaciers respond four to seven years later, with the Mer de Glace reacting last —between eleven and fifteen years after changes are first observed in the movement of ice in the Bossons Glacier. Even the smallest glaciers can have

3485-496: The Mont Blanc massif, all of which can be easily reached or viewed. Glaciers cover 170 square kilometres (66 sq mi) of the massif, of which 110 km (42 sq mi) fall within France. The Mer de Glace is the largest glacier in the western Alps , and the second largest in Europe. It has a total length of 12 km (7.5 mi) from highest snowfield to terminus and an area of 35–40 km (14–15 sq mi). At around 10 km (6 mi) in length,

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3570-471: The Mont Blanc massif: Seven of the massif's largest indigenous mammal species are housed in the Merlet Animal Park near Les Houches, including ibex, chamois, marmot, fallow and roe deer . Located 600 metres (2,000 ft) above the village, the park was founded in 1968 and contains eighty animal species from mountain habitats around the world. The region in which the Mont Blanc massif

3655-533: The Rocher Rouges, high up on Mont Blanc, during an expedition organised by Joseph Hamel  [ de ] . Forty years later the remains of two of them were discovered, re-exposed within fissures in the Bossons glacier. They were 3,000 metres (9,800 ft) lower down from the point where they were lost; the corpse of the third guide was discovered the following year. In 2014, a group of climbers found

3740-482: The Tour Ronde being the first to be analysed. Measurements were taken in July 2005 and again in July 2006. An area of the east face of 67,400 m was laser-scanned, creating 22 overlapping computer images, with measurements accurate to between 3 and 5 cm. Careful computer analysis revealed that in the twelve-month period between scans, the measured area had lost 536 m³ of rock. This is comparable to an erosion rate across

3825-642: The Tour of Mont Blanc. When Savoy was eventually annexed to France in 1860, Napoleon III and Empress Eugénie visited the region to mark the event and undertook to enhance road access leading to the end of the Arve valley. The 19th century saw considerable economic development which turned the small agricultural town of Chamonix into a base for tourists, with luxurious hotels and mountain lodges being built to accommodate them. A trade in selling local items to visiting foreigners soon developed. Crystals collected from across

3910-436: The accumulated steeps; Amongst many other notable visitors were: Goethe (1779); Chateaubriand (1805); Madame de Staël ; Victor Hugo ; Louis Pasteur and Franz Liszt (1836), plus two successive wives of Napoleon Bonaparte : Joséphine de Beauharnais (1810) and Marie Louise of Austria (1814). In 1849, John Ruskin spent a month in Chamonix, from where he painted some of the massif's mountains before undertaking

3995-448: The earth's crust lifted up schist , gneiss and limestone rocks. These were destined to form the base of the Alps range, and this period of upheaval ended 300   million years ago. Granite intrusions and associated metamorphic rocks formed the base of the mountains we now call the Mont Blanc massif as well as the nearby Aiguilles Rouges . But these rocks were then heavily eroded away, eventually being ground down and inundated by

4080-523: The entire measured area of the face of 8.4 mm per year – a figure significantly greater than those found in rock walls of high-altitude permafrost in Switzerland and Greenland. The project concluded that the higher rock fall rate exhibited on the Tour Ronde and elsewhere in the Mont Blanc massif was linked to the degradation in permafrost which would have held the mountain together more effectively, but which now exposed it to greater weathering through

4165-423: The expansion of ice when water freezes, putting considerable stress on the walls of containment. This is actually a very common process in all humid, temperate areas where there is exposed rock, especially porous rocks like sandstone . Sand can often be found just under the faces of exposed sandstone where individual grains have been popped off, one by one. This process is often termed frost spalling. In fact, this

4250-409: The following species of flowering plants amongst rocky debris around permanent snow fields and the highest alpine glaciers: Achillea nana  [ fr ] ; Achillea atrata ; Gentiana nivalis ; Juncus trifidus ; Ranunculus glacialis ; Saxifraga biflora  [ de ] and Saxifraga oppositifolia . In the mid-1800s, Venance Payot , a Chamonix naturalist , published

4335-423: The glacier is now a cause of serious concern. The inexorable downward movement and melting of glaciers can result in objects lost within them reappearing many years later. The first recorded account of a body reappearing from a glacier in the Mont Blanc range was made by Viscount Edmond de Catelin in 1861. It concerned three alpine guides who were buried in a crevasse during an avalanche on 20 August 1820 near

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4420-519: The glaciers and mountains were "discovered" by the outside world in the 18th century. Word of these impressive sights began to spread, and Mont Blanc was first climbed in 1786, marking the start of the sport of mountaineering. The region is now a major tourist destination, drawing in over six   million visitors per year. It provides a wide range of opportunities for outdoor recreation and activities such as sight-seeing, hiking , rock climbing , mountaineering and skiing . Around one hundred people

4505-596: The highest in Switzerland being the Aiguille d'Argentière. The massif is amongst the three major subranges of the Alps having the highest concentration of four-thousanders, together with the Pennine Alps and the Bernese Alps . The first ascent of Mont Blanc in 1786 by Jacques Balmat and Michel Paccard initiated the sport of alpine mountaineering, and it was during the golden age of alpinism (1854–65) and

4590-414: The highest mountain in the Alps and in western Europe. From the summit of Mont Blanc to the Arve near Chamonix there is a 3,800 metres (12,500 ft) drop in altitude over a distance of just 8 kilometres (5.0 mi). Because of its great elevation, much of the massif is snow- and ice-covered, and has been deeply dissected by glaciers. The Mer de Glace is the longest glacier in the range as well as

4675-432: The highest point at 4,808 metres (15,774 ft). Whilst the Mont Blanc massif does not contain any species that are endemic to it, there are many rare and legally protected species found within its four major habitat zones. These are the: montane forests , sub-alpine, alpine and nival zones . The major habitats are coniferous forests , moors , rock and talus slopes , plus glacial moraines . The biological richness

4760-911: The landscape ground down and shaped the mountains and the valleys as seen today. Both the Mont Blanc massif, and the Aiguilles Rouges range to its north, now form part of the external zone of the Alps, effectively being the outermost layers of rock. The central granites make up Mont Blanc, the steep slopes of the Drus , the Grandes Jorasses and the Dent du Géant, and at the highest points are topped by schists, which are visible in places such as Grands Montets and near Mont Blanc's summit. The granite mountains around Chamonix have been eroded into steep needle-shaped peaks (known as aiguilles ). Known locally as protogine , these rocks are lower in

4845-478: The longest in France and the second longest in the Alps. The debris-covered Miage Glacier on the southern side of the massif is the longest in Italy. The summit of Mont Blanc is an ice cap whose thickness varies from year to year. The entire massif can be circumnavigated by the Tour du Mont Blanc , a walking route of approximately 170 kilometres (110 mi). It usually takes around 11 days to complete, but

4930-562: The massif lies mostly within France, and is bounded by the valley of the Arve , containing the towns of Argentière , Chamonix and Les Houches . To the west it is bounded by the Val Montjoie, containing Les Contamines-Montjoie and the river Le Bon Nant which flows northwards to a confluence with the Arve near Saint-Gervais-les-Bains , and onwards to the Rhône . The southern side of

5015-425: The massif were much in demand, as were locally produced goods such as horn trinkets and honey. Frost weathering Frost weathering is a collective term for several mechanical weathering processes induced by stresses created by the freezing of water into ice . The term serves as an umbrella term for a variety of processes, such as frost shattering, frost wedging, and cryofracturing. The process may act on

5100-418: The massif's great overall height, a considerable proportion is permanently glaciated or snow-covered and is exposed to extremely cold conditions. Even on the high passes of the Tour du Mont Blanc, around 2,000 to 2,500 m (6,600 to 8,200 ft), summer temperatures can be between 5 and 15 °C (41 and 59 °F), but feeling much colder because of wind chill in windy or wet conditions. Precipitation

5185-403: The massif, from the valley bottoms right up to 3,800 m (12,500 ft) where the alpine chrysanthemum ( Leucanthemopsis alpina  [ fr ] ) can be found at a record-breaking height. Early explorers, such as Alexander von Humboldt in 1807, observed a number of notable species in the mountains around Mont Blanc at altitudes above 3,100 metres (10,200 feet). This was well above

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5270-621: The mid-way station of the Skyway Monte Bianco , or on foot from La Palud within two hours and an ascent of 800 m (2,600 ft). The botanical garden derives its name from the genus of mountain flowers, Saussurea (Saw-worts) which itself was named after Horace-Bénédict de Saussure , whose enthusiasm for scientific research in the mountains led to the first ascent of Mont Blanc in 1786. The mountains around Mont Blanc are home to many mammal species, including ibex, chamois , deer, mountain hare and alpine marmot (including

5355-400: The mineral biotite mica and richer in quartz than the granites commonly found elsewhere. A large part of the massif is covered by ice fields and is cut by numerous glaciers, mostly flowing northwestwards on the French side; southeastwards on the Italian side and eastwards on the Swiss side. With much steeper slopes on the Italian side, many glaciers drop very sharply and some, such as

5440-425: The modern Tour du Mont Blanc walking trail still follow the route of a Roman road along the Col du Bonhomme and the Col de la Seigne. The Romans occupied Martigny to the north of the massif, and their influence spread out well beyond the Alps into much of northern Europe. As a result of aggressive pressure from tribes in the north, the imperial forces of Rome were gradually withdrawn from the alpine regions until, by

5525-462: The months of November and April. The best weather for mountaineering or hiking occurs between late June to early October but, being the highest part of the Alps, the Mont Blanc massif can create its 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

5610-404: The mountain's popularity and accessibility, it can be difficult to determine whether the routes are actually new or not. In 2005 the Tour Ronde became the first high mountain ever to be subject to extremely detailed laser-scanning and monitoring. Amid growing concern in recent decades that climate change had been increasing the incidence of severe rock-fall and loss of permafrost at high altitude,

5695-416: The mountains of the Mont Blanc range to the attention of a wide audience for the first time. In 1760, Horace-Bénédict de Saussure offered a large financial prize to the first people who successfully ascended Mont Blanc. The summit was finally attained on 8 August 1786 by two Chamonix men, the guide Jacques Balmat and Dr. Michel Paccard . The decades that followed saw the gradual opening up of Chamonix to

5780-730: The name Alpes Penninae , or Poeninae , to the highest parts of the Alps—which extended from Mont Blanc to Monte Rosa . They took over Aosta from the Salassi Celtic tribe in 25 AD and engineered roads which extended northwards into Europe via the Great St Bernard Pass and the Little St Bernard Pass . Courmayeur, on the southern side of the massif, began to develop as a stop-off along their trans-alpine trading routes between Italy and France. Parts of

5865-419: The need for better environmental protection, including a call for World Heritage Site status. The Mont Blanc massif is 46 kilometres (29 mi) long and lies in a southwest to northeasterly direction across the borders of France ( Haute-Savoie and Savoie ), Italy ( Aosta Valley ) and Switzerland (western Valais ). At its widest point the massif is 20 km (12 mi) across. The northwestern side of

5950-547: The northern end of the massif is drained by the Trient , also joining the Rhône near Martigny. The borders of all three countries converge at a tripoint near the summit of Mont Dolent at an altitude of 3,820 metres (12,533 ft). From here the French – Italian border runs southwestwards along a ridge of high summits on the southern side of the massif, many of which are over 4,000 metres (13,123 ft) in height, including

6035-558: The northern side of the Swiss Alps . The climate of the Mont Blanc massif is cold and temperate ( Köppen climate classification Cfb ), and is greatly influenced by altitude. The main valley settlements around the perimeter of the massif are at an altitude ranging between 600 and 1,200 metres (2,000 and 3,900 ft). Daytime valley temperatures in July and August may range up to 25 °C (77 °F), sometimes reaching 30 °C (86 °F). The greatest snowfall occurs between

6120-497: The permanent snow line, but on rocks that were so steep that little snow could rest. These arctic-alpine species included: Androsace carnea  [ es ] ; Androsace chamaejasme  [ de ] ; Arabis caerulea  [ de ] ; Cardamine bellidifolia ; Draba hirta ; Saxifraga androsacea  [ es ] and Silene acaulis (occurring down to 1,500 m (4,900 ft)). Between 2,500 and 3,100 m (8,200 and 10,200 ft), Humboldt noted

6205-457: The pore water that breaks the rock, the result is called hydrofracture. Hydrofracturing is favoured by large interconnected pores or large hydraulic gradients in the rock. If there are small pores, a very quick freezing of water in parts of the rock may expel water, and if the water is expelled faster than it can migrate, pressure may rise, fracturing the rock. Since research in physical weathering begun around 1900, volumetric expansion was, until

6290-488: The public in 2006 and tells the story of the early crystal-hunters (known as cristalliers ). Many specimens collected from across the massif are displayed there. Located on the watershed between the Rhône and the Po , the Mont Blanc massif 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

6375-616: The sea, so allowing sedimentary rocks to form. Then, once again, this part of the Earth's crust was uplifted as a result of the collision of continental plates . The huge mountain ranges of today's Alps began to form. This happened towards the end of the Tertiary period, 15   million years ago. Finally, came the Quaternary era, when successive ice ages saw vast glaciers advance, retreat, and then advance again. Their movement across

6460-436: The site of one of two Air India plane crashes. These occurred at almost identical locations high up near the summit of Mont Blanc: one in 1950 ( Air India Flight 245 ), and one in 1966 ( Air India Flight 101 ). Debris from these crashes is still commonly found on the glacier below. The Mont Blanc massif consists predominantly of ancient granite rocks. The Alps have their origins 770   million years ago when upheaval of

6545-512: The slopes below les Courtes had yielded many large specimens. He recounted that in 1745 a guide had stated he had collected over 300 pounds (136 kg) of specimens there in just three hours. 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

6630-514: The southern Alps. The mountains of the massif consist mostly of granite and gneiss rocks and at high altitudes the vegetation is an arctic-alpine flora. The valleys that delimit the massif were used as communication routes by the Romans until they left around the 5th century AD. The region remained of some military importance through to the mid-20th century. A peasant farming economy operated within these valleys for many centuries until

6715-589: 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 a height of 4,300 metres (14,100 ft). In the mountains further south of the Mont Blanc range, annual precipitation is significantly less than at equivalent altitudes within the massif. For example, the valleys in the Pelvoux massif at around 1,000 metres (3,300 ft) receive only around 600 to 700 mm (24 to 28 in) of precipitation per year, which

6800-421: The summits, ranging greatly in both length and difficulty. These attract climbers from all over the world who, unlike the early ascensionists, now have access to numerous climbing guidebooks, modern safety equipment, good information on climbing routes and technical difficulty, as well as weather forecasts and mountain accommodation and food. A wide range of glaciers and glacial structures can be found across

6885-461: The water does not migrate away and the pressure is exerted on the rock. These conditions are considered unusual, restricting it to a process of importance within a few centimeters of a rock's surface and on larger existing water-filled joints in a process called ice wedging . Not all volumetric expansion is caused by the pressure of the freezing water; it can be caused by stresses in water that remains unfrozen. When ice growth induces stresses in

6970-476: The watershed of the col de la Seigne), and its waters flow southwards towards the Isère and onwards to the Rhône. The northernmost section of the massif falls within Switzerland, and is bounded to the east by a separate valley, confusingly also called Val Ferret , and which separates it from the Pennine Alps . Its watercourse, la Dranse de Ferret , flows northwards to join the Rhône at Martigny . The west side of

7055-464: The world, as well as the rest of the Mont Blanc massif. The many published accounts of climbs and impressive sights amongst or around the mountain range attracted numerous wealthy and notable visitors, for whom a visit to marvel at the Sea of Ice (the Mer de Glace) became a fashionable thing to experience. In July 1816, Mary Shelley and Percy Bysshe Shelley toured the Alps and visited Chamouni (as it

7140-428: Was inspired by the river Arve, the snow-covered summits, the chaotic glaciers and the forests that he experienced during their visit. Far, far above, piercing the infinite sky, Mont Blanc appears—still, snowy, and serene— Its subject mountains their unearthly forms Pile around it, ice and rock; broad vales between Of frozen floods, unfathomable deeps, Blue as the overhanging heaven, that spread And wind among

7225-544: Was then known), as well as the Mer de Glace and the Bossons Glacier. They jointly published their accounts and letters in a work entitled: History of a Six Weeks' Tour through a part of France, Switzerland, Germany, and Holland; with Letters Descriptive of a Sail Round the Lake of Geneva and of the Glaciers of Chamouni . The book concludes with Mont Blanc , a 144-line poem by Percy Shelley, written whilst in Chamonix and which

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