Misplaced Pages

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79-411: The prominence of a peak is the least drop in height necessary in order to get from the summit to any higher terrain. This can be calculated for a given peak in the following manner: for every path connecting the peak to higher terrain, find the lowest point on the path; the key col (or highest saddle , or linking col , or link ) is defined as the highest of these points, along all connecting paths;

158-450: A topographic map . However, when the key col is far away, or when one wants to calculate the prominence of many peaks at once, software can apply surface network modeling to a digital elevation model to find exact or approximate key cols. Since topographic maps typically show elevation using contour lines , the exact elevation is typically bounded by an upper and lower contour, and not specified exactly. Prominence calculations may use

237-420: A "closer" peak than the encirclement parent (if there is one), which is still "better" than the peak in question. The differences lie in what criteria are used to define "closer" and "better." The (prominence) parent peak of peak A can be found by dividing the island or region in question into territories, by tracing the two hydrographic runoffs, one in each direction, downwards from the key col of every peak that

316-493: A "hierarchy" of peaks going back to the highest point on the island. One such chain in Britain would read: Billinge Hill → Winter Hill → Hail Storm Hill → Boulsworth Hill → Kinder Scout → Cross Fell → Helvellyn → Scafell Pike → Snowdon → Ben Nevis . At each stage in the chain, both height and prominence increase. Line parentage, also called height parentage, is similar to prominence parentage, but it requires

395-460: 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 1,030 m (3,380 ft). It receives around 1,020 mm (40 in) of annual precipitation, whilst the Col du Midi, which

474-420: A criterion for inclusion in the list, or cutoff . John and Anne Nuttall's The Mountains of England and Wales uses a cutoff of 15 m (about 50 ft), and Alan Dawson's list of Marilyns uses 150 m (about 500 ft). (Dawson's list and the term "Marilyn" are limited to Britain and Ireland). In the contiguous United States, the famous list of " fourteeners " (14,000 foot / 4268 m peaks) uses

553-509: A cutoff of 300 ft / 91 m (with some exceptions). Also in the U.S., 2000 ft (610 m) of prominence has become an informal threshold that signifies that a peak has major stature. Lists with a high topographic prominence cutoff tend to favor isolated peaks or those that are the highest point of their massif ; a low value, such as the Nuttalls', results in a list with many summits that may be viewed by some as insignificant. While

632-480: A distance of 13,655 km (8,485 miles). The key col for the South Summit of Mount Everest is about 100 m (330 feet) distant. A way to visualize prominence is to imagine raising sea level so the parent peak and subject peak are two separate islands. Then lower it until a tiny land bridge forms between the two islands. This land bridge is the key col of the subject peak, and the peak's prominence

711-407: A great deal of information about the peak's position. In general, the analysis of parents and lineages is intimately linked to studying the topology of watersheds . Alteration of the landscape by humans and presence of water features can give rise to issues in the choice of location and height of a summit or col. In Britain, extensive discussion has resulted in a protocol that has been adopted by

790-462: 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 suffer altitude sickness , occasionally life-threatening, particularly if they are not properly acclimatised . A 1994 estimate suggests there had been 6,000 to 8,000 alpinist fatalities in total, more than on any other mountain. These numbers exclude

869-485: A hierarchy which defines some peaks as subpeaks of others. For example, in Figure ;1, the middle peak is a subpeak of the right peak, which is a subpeak of the left peak, which is the highest point on its landmass. In that example, there is no controversy about the hierarchy; in practice, there are different definitions of parent. These different definitions follow. Also known as prominence island parentage , this

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948-413: A highest submerged col of about 40 m, or only 8888 m below the peak of Everest. As a result, Mauna Kea's prominence might be subjectively more impressive than Everest's, and some authorities have called it the tallest mountain from peak to underwater base. Dry prominence is also useful for measuring submerged seamounts . Seamounts have a dry topographic prominence, a topographic isolation , and

1027-597: A large intrusion of granite (termed a batholith ) 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

1106-507: A negative topographic elevation . Prominence values are accurate to perhaps 100m owing to uncertainties in ocean sounding depths. Col A col in geomorphology is the lowest point on a mountain ridge between two peaks . It may also be called a gap or pass . Particularly rugged and forbidding cols in the terrain are usually referred to as notches . They are generally unsuitable as mountain passes , but are occasionally crossed by mule tracks or climbers' routes. Derived from

1185-409: A prominence cutoff criterion. The height parent is the closest peak to peak A (along all ridges connected to A) that has a greater height than A, and satisfies some prominence criteria. The disadvantage of this concept is that it goes against the intuition that a parent peak should always be more significant than its child. However it can be used to build an entire lineage for a peak which contains

1264-437: A prominence-ranked list is that it needs no cutoff since a peak with high prominence is automatically an independent peak. It is common to define a peak's parent as a particular peak in the higher terrain connected to the peak by the key col. If there are many higher peaks there are various ways of defining which one is the parent, not necessarily based on geological or geomorphological factors. The "parent" relationship defines

1343-666: A second interpretation places both summits, as well as that of Mont Blanc de Courmayeur (although much less clearly in the latter case), 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. In 1890, Pierre Janssen , an astronomer and the director of the Meudon astrophysical observatory, considered

1422-474: A sufficient degree of prominence are regarded as independent mountains. For example, the world's second-highest mountain is K2 (height 8,611 m, prominence 4,017 m). While Mount Everest 's South Summit (height 8,749 m, prominence 11 m) is taller than K2, it is not considered an independent mountain because it is a sub-summit of the main summit (which has a height and prominence of 8,848 m). Many lists of mountains use topographic prominence as

1501-484: Is Aconcagua (6,960 m), in Argentina , and its prominence is 6,138 m. (To further illustrate the rising-sea model of prominence, if sea level rose 56 m, North and South America would be separate continents and Denali would be 6138 m, its current prominence, above sea level. At a slightly lower level, the continents would still be connected and the high point of the combined landmass would be Aconcagua,

1580-642: Is approximately 65 hectares (160 acres) on Mont Blanc and ten hectares (25 acres) 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 (1796), France claims that the historical border of Savoy and Piedmont diverged from the watershed line, fully encompassing

1659-418: 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). The Mont Blanc was the highest mountain of

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1738-441: Is becoming preferred. There are two varieties of topographic prominence: wet prominence and dry prominence. Wet prominence is the standard topographic prominence discussed in this article. Wet prominence assumes that the surface of the earth includes all permanent water, snow, and ice features. Thus, the wet prominence of the highest summit of an ocean island or landmass is always equal to the summit's elevation. Dry prominence, on

1817-470: Is being put forward as a potential World Heritage Site because of its uniqueness and cultural importance considered the birthplace and symbol of modern mountaineering. It would require the three governments of Italy, France and Switzerland to request UNESCO for it to be listed. Mont Blanc is one of the most visited tourist destinations in the world. For this reason, some view it as threatened. Pro-Mont Blanc (an international collective of associations for

1896-406: Is defined as follows. In Figure 2 the key col of peak A is at the meeting place of two closed contours, one encircling A (and no higher peaks) and the other containing at least one higher peak. The encirclement parent of A is the highest peak that is inside this other contour. In terms of the falling-sea model, the two contours together bound an "island", with two pieces connected by an isthmus at

1975-465: Is equal to its wet prominence (4205 m) plus the depth of its highest submerged col (about 5125 m). Totaling 9330 m, this is greater than any mountain apart from Everest. The dry prominence of Aconcagua is equal to its wet prominence (6960 m) plus the depth of the highest submerged col of the Bering Strait (about 40 m), or about 7000 m. It is worth noting Mauna Kea

2054-559: Is equal to its wet prominence plus the depth of its highest submerged col. Because Earth has no higher summit than Mount Everest , Everest's prominence is either undefined or its height from the lowest contour line. In a dry Earth, the lowest contour line would be the deepest hydrologic feature, the Challenger Deep , at 10,924 m depth. Everest's dry prominence would be this depth plus Everest's wet prominence of 8848 m, totaling 19,772 m. The dry prominence of Mauna Kea

2133-458: 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,

2212-451: Is its elevation from that key col. Prominence is interesting to many mountaineers because it is an objective measurement that is strongly correlated with the subjective significance of a summit. Peaks with low prominence are either subsidiary tops of some higher summit or relatively insignificant independent summits. Peaks with high prominence tend to be the highest points around and are likely to have extraordinary views. Only summits with

2291-404: Is more prominent than peak A. The parent is the peak whose territory peak A is in. For hills with low prominence in Britain, a definition of "parent Marilyn " is sometimes used to classify low hills ("Marilyn" being a British term for a hill with a prominence of at least 150 m). This is found by dividing the region of Britain in question into territories, one for each Marilyn . The parent Marilyn

2370-457: Is not used because there is no obvious choice of cutoff. This choice of method might at first seem arbitrary, but it provides every hill with a clear and unambiguous parent peak that is taller and more prominent than the hill itself, while also being connected to it (via ridge lines). The parent of a low hill will also usually be nearby; this becomes less likely as the hill's height and prominence increase. Using prominence parentage, one may produce

2449-590: Is relatively close to its submerged key col in the Pacific Ocean, and the corresponding contour line that surrounds Mauna Kea is a relatively compact area of the ocean floor. Whereas a contour line around Everest that is lower than 9330m from Everest's peak would surround most of the major continents of the Earth. Even just surrounding Afro-Eurasia would run a contour line through the Bering Straight, with

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2528-616: Is the second-most prominent mountain in Europe, after Mount Elbrus , and the 11th most prominent mountain in the world. It gives its name to 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

2607-694: Is the Marilyn whose territory the hill's summit is in. If the hill is on an island (in Britain) whose highest point is less than 150 m, it has no parent Marilyn. Prominence parentage is the only definition used in the British Isles because encirclement parentage breaks down when the key col approaches sea level. Using the encirclement definition, the parent of almost any small hill in a low-lying coastal area would be Ben Nevis , an unhelpful and confusing outcome. Meanwhile, "height" parentage (see below)

2686-470: 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

2765-542: The 2003 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 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 4,808.45 m (15,775 ft 9 in), and

2844-705: The Frankish Empire under Charlemagne and the highest mountain of the Holy Roman Empire until 1792. 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 (at

2923-642: 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

3002-655: The key col ) is effectively a measure of a mountain's topographic prominence . Cols lie on the line of the watershed between two mountains , often on a prominent ridge or arête . For example, the highest col in Austria, the Obere Glocknerscharte ("Upper Glockner Col", 3,766  m (AA) ) lies between the Kleinglockner ( 3,783 m above sea level (AA) ) and Grossglockner ( 3,798 m above sea level (AA) ) mountains, giving

3081-492: 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

3160-431: The "father" of India's nuclear programme. In 1946, a drilling project was initiated to carve a tunnel through the mountain. The Mont Blanc tunnel would connect Chamonix , France, and Courmayeur , 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). In 1999, a transport truck caught fire in

3239-636: 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 the Gouter Hut was closed by municipal decree for some days because of a very high rockfall danger, with some stranded climbers evacuated by helicopter. In 2016 a crevasse opened at high altitude, also indicating previously unobserved glacial movements. The new crevasse forms an obstacle to be scaled by climbing parties on

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3318-459: 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

3397-408: The French col ("collar, neck") from Latin collum , "neck", the term tends to be associated more with mountain than hill ranges. The distinction with other names for breaks in mountain ridges such as saddle , wind gap or notch is not sharply defined and may vary from place to place. Many double summits are separated by prominent cols. The height of a summit above its highest col (called

3476-674: The Kleinglockner a minimum prominence of 17 metres. Mont Blanc Mont Blanc ( BrE : / ˌ m ɒ̃ ˈ b l ɒ̃ ( k )/ ; AmE : / ˌ m ɒ n ( t ) ˈ b l ɑː ŋ k / ) is the highest mountain in the Alps and Western Europe , and the highest mountain in Europe outside the Caucasus Mountains , rising 4,805.59 m (15,766 ft) above sea level, located on the Franco-Italian border . It

3555-477: 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 and Mont Maudit , before

3634-618: The annexation of Savoy (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

3713-408: The child peak. For example, one common use of the concept of parent is to make clear the location of a peak. If we say that Peak A has Mont Blanc for a parent, we would expect to find Peak A somewhere close to Mont Blanc. This is not always the case for the various concepts of parent, and is least likely to be the case for encirclement parentage. Figure 3 shows a schematic range of peaks with

3792-410: The color underlying the minor peaks indicating the encirclement parent. In this case the encirclement parent of M is H whereas an intuitive view might be that L was the parent. Indeed, if col "k" were slightly lower, L would be the true encirclement parent. The encirclement parent is the highest possible parent for a peak; all other definitions indicate a (possibly different) peak on the combined island,

3871-454: 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,

3950-488: The disadvantage in using the encirclement parent. A hill in a low-lying area like the Netherlands will often be a direct child of Mount Everest , with its prominence about the same as its height and its key col placed at or near the foot of the hill, well below, for instance, the 113-meter-high key col of Mont Blanc . When the key col for a peak is close to the peak itself, prominence is easily computed by hand using

4029-457: The disaster. 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, the IGN and expert surveyors, with the aid of GPS technology, measured it to be 4,807.40 m (15,772 ft 4 in). After

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4108-475: The encirclement parent.) While it is natural for Aconcagua to be the parent of Denali, since Denali is a major peak, consider the following situation: Peak A is a small hill on the coast of Alaska, with elevation 100 m and key col 50 m. Then the encirclement parent of Peak A is also Aconcagua, even though there will be many peaks closer to Peak A which are much higher and more prominent than Peak A (for example, Denali). This illustrates

4187-562: 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. The recent temperature rises and heatwaves, such as those of the summers of 2015 and 2018, have significantly impacted many climbing routes across

4266-459: The fatalities of Air India Flight 245 and Air India Flight 101 , two planes that crashed into Mont Blanc. Despite unsubstantiated claims recurring in media that "some estimates put the fatality rate at an average of 100 hikers a year", 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. A French study on

4345-821: The final part of the itinerary to the top shared by the popular Goûter Route and the Grand Mulets Route. In July 2014, an American entrepreneur and traveller Patrick Sweeney attempted to break the record with his nine-year-old son and 11-year-old daughter. They were caught in an avalanche , escaped death and decided not to pursue their attempt. In August 2014, an unknown Austrian climber with his 5-year-old son were intercepted by mountain gendarmes at 3,200 m (10,500 ft) and forced to turn back. On 5 August 2017, 9-year-old Hungarian 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. The Mont Blanc massif

4424-425: 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

4503-489: The high contour (giving in a pessimistic estimate), the low contour (giving an optimistic estimate), their mean (giving a "midrange" or "rise" prominence) or an interpolated value (customary in Britain). The choice of method depends largely on the preference of the author and historical precedent. Pessimistic prominence, (and sometimes optimistic prominence) were for many years used in USA and international lists, but mean prominence

4582-453: The key col. The encirclement parent is the highest point on this entire island. For example, the encirclement parent of Mont Blanc , the highest peak in the Alps , is Mount Everest . Mont Blanc's key col is a piece of low ground near Lake Onega in northwestern Russia (at 113 m (371 ft) elevation), on the divide between lands draining into the Baltic and Caspian Seas . This is

4661-563: 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 saved in extremis . The mountain was the scene of two fatal air crashes; Air India Flight 245 in 1950 and Air India Flight 101 in 1966. Both planes were approaching Geneva Airport and the pilots miscalculated their descent; 48 and 117 people, respectively, died. The passengers on flight 101 included nuclear scientist Homi J. Bhabha , known as

4740-597: 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 (distinct) disputed areas

4819-433: The main sources of prominence data in Britain and Ireland. Other sources of data commonly ignore human-made alterations, but this convention is not universally agreed upon; for example, some authors discount modern structures but allow ancient ones. Another disagreement concerns mountaintop removal , though for high-prominence peaks (and for low-prominence subpeaks with intact summits), the difference in prominence values for

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4898-420: The meeting place of two 113 m (371 ft) contours, one of them encircling Mont Blanc; the other contour encircles Mount Everest. This example demonstrates that the encirclement parent can be very far away from the peak in question when the key col is low. This means that, while simple to define, the encirclement parent often does not satisfy the intuitive requirement that the parent peak should be close to

4977-402: The other hand, ignores water, snow, and ice features and assumes that the surface of the earth is defined by the solid bottom of those features. The dry prominence of a summit is equal to its wet prominence unless the summit is the highest point of a landmass or island, or its key col is covered by snow or ice. If its highest surface col is on water, snow, or ice, the dry prominence of that summit

5056-443: 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 of climate 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

5135-441: The prominence is the difference between the elevation of the peak and the elevation of its key col. On a given landmass, the highest peak's prominence will be identical to its elevation. An alternative equivalent definition is that the prominence is the height of the peak's summit above the lowest contour line encircling it, but containing no higher summit within it; see Figure 1. The parent peak may be either close or far from

5214-423: 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 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

5293-645: The same period. Modern Swiss mapping, published by the Federal 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,

5372-405: 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 as staging areas to control commercial traffic during peak hours. The renovated tunnel reopened three years after

5451-522: The subject peak. The summit of Mount Everest is the parent peak of Aconcagua in Argentina at a distance of 17,755 km (11,032 miles), as well as the parent of the South Summit of Mount Everest at a distance of 360 m (1200 feet). The key col may also be close to the subject peak or far from it. The key col for Aconcagua, if sea level is disregarded, is the Bering Strait at

5530-709: The summit area has long been disputed between France and Italy. The Mont Blanc massif is popular for outdoor activities like hiking , climbing , trail running and winter sports like 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

5609-678: The summit of Mont Blanc on a clear day, the Jura , the Vosges , the Black Forest , and the Massif Central mountain ranges can be seen, as well as the principal summits of the Alps. Several classic climbing routes lead to the summit of Mont Blanc: 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

5688-829: 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

5767-429: The time neither within Italy nor France) 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. At the scale of the Mont Blanc massif , the border between Italy and France passes along most of

5846-401: 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

5925-500: The two conventions is typically relatively small. The key col and parent peak are often close to the sub-peak but this is not always the case, especially when the key col is relatively low. It is only with the advent of computer programs and geographical databases that thorough analysis has become possible. For example, the key col of Denali in Alaska (6,194 m) is a 56 m col near Lake Nicaragua . Denali's encirclement parent

6004-449: The use of prominence as a cutoff to form a list of peaks ranked by elevation is standard and is the most common use of the concept, it is also possible to use prominence as a mountain measure in itself. This generates lists of peaks ranked by prominence , which are qualitatively different from lists ranked by elevation. Such lists tend to emphasize isolated high peaks, such as range or island high points and stratovolcanoes . One advantage of

6083-653: The wider range of the Mont Blanc massif. 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 ( Köppen climate classification Cfb ), and

6162-497: 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. 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). 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). From

6241-455: 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 11.6 km ( 7 + 1 ⁄ 4  mi) Mont Blanc Tunnel , constructed between 1957 and 1965, runs beneath the mountain and is a major transalpine transport route. Mont Blanc and adjacent mountains in the massif are predominately formed from

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