Misplaced Pages

#436563

24-450: The glacier is located on the northwestern slopes of the Aiguille du Goûter , on the northern side of Mont Blanc and 11 km upstream of the town of Saint-Gervais. It lies at an altitude of 3,300 metres (10,800 ft), descending to a height of 3,100 metres (10,200 ft), and is predominantly avalanche-fed from snows falling from the steep slopes of Aiguille du Goûter above. As at 2007,

48-407: A 3-metre-high (10 ft) tube led back some 85 metres (280 ft) and at a 36° angle to an even larger second cavity, up to 40 metres (130 ft) high and 50 metres (160 ft) wide. Maps drawn up shortly afterwards confirmed a depression in the centre of the glacier. It was estimated that 100,000 cubic metres (81 acre⋅ft) of liquid water had drained away during the glacier's collapse, plus

72-433: A further 100,000 cubic metres (130,000 cu yd) of broken ice. Together with the soil and rock broken away by the force of the rushing water, Vallot estimated that a weight of 500,000,000 kilograms (500,000 t; 550,000 short tons) of material had borne down on the villages. He also warned that a repeat of water build-up was quite likely to occur, and that this would become more dangerous as time went on. He advocated

96-462: A repeat of the 1892 outburst flood which would impact upon those living in the valley below. The Mont Blanc glacier flood was a devastating outburst flood that occurred on 11 July 1892. The disaster took place at night-time when the Tête Rousse Glacier suddenly released 200,000 cubic metres (160 acre⋅ft) of water from large pockets of water which had accumulated within the structure of

120-469: Is a rack and adhesion railway, using the Strub design to overcome a height difference of 1,792 m (5,879 ft). The line has an average gradient of 15% and a maximum gradient of 24%. Some 85% of the line is equipped with rack rail, with adhesion being used at the foot of the line and at intermediate crossing stations . The line is electrified using an overhead line at 11 kV and 50 Hz AC . The line

144-612: Is a mountain in the Mont Blanc massif of Haute-Savoie , France . This Haute-Savoie geographical article is a stub . You can help Misplaced Pages by expanding it . Mont Blanc Tramway The Mont Blanc tramway or Tramway du Mont-Blanc ( TMB ) is a mountain railway line in the Haute-Savoie department of France . It is the highest in France and the fourth highest in Europe . It

168-548: Is also the only railway in France reaching over 2,000 metres above sea level. The extensive views of Mont Blanc and adjacent mountains of the Mont Blanc massif provided by the tramway make it popular with tourists. Also, mountaineers and hikers use the tramway because its stops provide the jumping off points for many trails, as well as giving access to the Refuge Nid d'Aigle close to the terminus of railway. The normal alpine mountaineering route to climb Mont Blanc starts at

192-612: Is operated by the Compagnie du Mont-Blanc  [ fr ] which also manages the Montenvers Railway and many ski lifts in the Mont Blanc region. The first section of the line, to the Col de Voza , was opened in 1907. The line reached its current terminus in August 1914 when work was suspended, because of World War I , and never resumed. The line was worked by steam locomotives until it

216-534: The glaciologist and Director of the Mont Blanc Observatory at the time of the incident, published detailed accounts of his investigations into the Catastrophy of Saint Gervais . Measurements and photographs taken shortly afterwards showed that part of the glacier's snout ( terminus ) had been torn away, revealing a cavity 40 metres (130 ft) in diameter and 20 metres (66 ft) above its base. From this

240-579: The Tramway and the nearby Nid d'Aigle mountain refuge was closed for safety reasons for the rest of the operational season. This was due to concerns of a repeat of a potentially catastrophic flood from release of a vast quantity of water that had built up within an intraglacial pocket within the Tête Rousse glacier lying directly above it. When the line was electrified in 1956, three electric multiple units were purchased named Marie , Jeanne and Anne after

264-577: The accepted explanation was that proposed by Joseph Vallot. It was believed that meltwater had drained through the glacier and become trapped as an intraglacial cavity, i.e. as an underground lake within a crevasse which itself had then become enlarged and widened by the water. However, recent re-analysis of historic photographs, accounts and contemporary meteorological precipitation data and field measurements, including radar analysis and magnetic resonance imaging, has presented an alternative and more plausible mechanism in which meltwater collected much closer to

SECTION 10

#1732854768437

288-493: The eventual outburst flood in 1892. In July 2010 a pocket containing 50,000 cubic metres (41 acre⋅ft) of water was detected in a glacial pocket, and some 48,000 cubic metres (39 acre⋅ft) of water were pumped out. A siren warning system was installed to aid evacuation of those at risk in the valley below, and evacuation plan was put in place. The final section of the Mont Blanc Tramway from St Gervais to Nid d'Aigle

312-423: The gendarmerie were mobilised, and an evacuation plan put into effect, involving the townspeople of St Gervais, Sallanches and Passy Domancy gathering at pre-arranged assembly points. Inspection of the glacier revealed that no collapse had taken place and the warning notice was lifted at 4:30am the same night. Studies revealed that between 35,000 and 50,000 cubic metres (28 and 41 acre⋅ft) of water were present in

336-425: The glacier had a total area of 0.08 square kilometres (0.031 sq mi; 20 acres) and a maximum thickness of 75 metres (246 ft)metres. The glacier is frequently crossed by mountaineers on their way to the Tête Rousse mountaineering hut , which stands at the side of the glacier at an altitude of 3,167 metres (10,390 ft). It is also crossed by many more climbers attempting the 'normal' route of ascent to

360-576: The glacier. By 2014 another build-up of a water pocket was discovered, and the Mayor of St. Gervais reported that, since its rediscovery, a total of 6 million euros had been spent in monitoring and pumping out water from the Tête Rousse glacier to protect the 3,000 inhabitants in the valley below. 45°51′21″N 6°49′09″E  /  45.8559°N 6.8193°E  / 45.8559; 6.8193 Aiguille du Go%C3%BBter Aiguille du Goûter (3,863 m)

384-501: The glacier. On 17 August 2012 part of the glacier's surface collapsed inwards. This created a large hole through which a glacial lake could be seen. Paths across the glacier were diverted, including that used to reach the Gouter Hut and thence the summit of Mont Blanc. At 1:47am on 29 July 2013 during a heavy storm, the alarm system on the glacier triggered, alerting the authorities to a serious flood risk. 95 firefighters and 70 soldiers of

408-474: The glacier. The collapse of the glacier and sudden release of water completely destroyed the hamlet of Bionnay and flooded the bath house in the town of Saint-Gervais , reaching as far as the hamlet of Le Fayet. Contemporary accounts show that over 200 people lost their lives in the villages. Everything in the path of the rushing water, mud and boulders was swept away, leaving behind some 800,000 cubic metres (1,000,000 cu yd) of sediment. Joseph Vallot ,

432-435: The highest railways in Europe and the second-highest when considering only open-air railways . The Nid d'Aigle and Mont Lachat (2,074 m (6,804 ft)), the two highest stations of the line, are the only railway stations over 2,000 metres in France. Both are well over the tree line . The line is 12.4 km (7.7 mi) long and has a rail gauge of 1,000 mm ( 3 ft  3 + 3 ⁄ 8  in ). It

456-470: The summit of Mont Blanc via the Goûter route. The Tête Rousse Glacier lies just above the considerably much larger Glacier de Bionnassay, yet the build-up of large water pockets within this small glacier continues to pose a very serious risk to life to this day, and has been the subject of much research and disaster planning, with considerable investment in risk-reduction measures. The main risk to life comes from

480-423: The surface (as a supraglacial lake ) in a period when the glacier had a negative mass balance (i.e. was experiencing year-on-year melting and retreat). Prior to 1878 the glacier would not have been well-visited, so any surface lake could have gone unnoticed, and after 1878 the glacier experienced a positive mass balance (i.e. year-on-year accumulation of snow and ice) which would have hidden the lake from view until

504-676: The tramway's terminus, Nid d'Aigle , and proceeds either to an overnight stop at the Tête Rousse Hut , or at the higher Goûter Hut . The line runs from a connection with the SNCF at Saint-Gervais-les-Bains Le Fayet station to the Nid d'Aigle station near the Bionnassay Glacier at an altitude of 2,372 m (7,782 ft). The initial intention was for the line to reach the much higher Aiguille du Goûter . Nevertheless, it remains one of

SECTION 20

#1732854768437

528-412: The use of explosives to ensure a permanent flow of meltwater away from the glacier. In 1904 a second water pocket was discovered within the glacier, and a hole was drilled to drain away 22,000 cubic metres (18 acre⋅ft). Opinions have differed as to the precise mechanism by which water had built up in such quantity and then had suddenly been released with such devastating consequences. For many years

552-472: Was closed for safety reasons for the rest of the operational season, as was the adjacent Nid d'Aigle mountain refuge . In 2011 water levels within the glacier were predicted to refill the glacial cavity before summer, and a further 25,000 cubic metres (20 acre⋅ft) of water was drained away. Further research was carried out to study and monitor the origin of the water. In 2012 results of research were presented showing that two water pockets existed within

576-418: Was electrified in 1956. The line is worked by three motor coaches which are named Anne , Marie and Jeanne . These were the names of the three daughters of the line's owner at the time of electrification. The journey time is one hour from Fayet to Bellevue with four or five trips operating per day. The Mont Blanc Tramway is featured in the film Malabar Princess . In late July 2010 the last section of

#436563