Seven Summits

From Wikipedia, the free encyclopedia

https://en.wikipedia.org/wiki/Seven_Summits 

The Seven Summits are the highest mountains of each of the seven traditional continents. Climbing to the summit of all of them is regarded as a mountaineering challenge, first achieved on 30 April 1985 by Richard Bass. Climbing the Seven Summits and additionally reaching the North and South poles has been dubbed the Explorers Grand Slam.

Definition

The Seven Summits are composed of each of the highest mountain peaks on each of the continents. Different lists include slight variations, but generally the same core is maintained. The seven summits depend on the definition used for a continent – in particular the location of the border of that continent. This results in two major points of variation. The first one is Mont Blanc versus Mount Elbrus for Europe, which depends on whether the crest of the Greater Caucasus Mountains is taken to define the Greater Caucasus watershed which marks the continental boundary between Asia and Europe for the region between the Black and Caspian seas; this classification would place Mount Elbrus in Asia instead of Europe. The second one is Puncak Jaya (also known as "Carstensz Pyramid") versus Mount Kosciuszko for the continent of Australia, which depends on whether one includes the Sahul Shelf or only mainland Australia as the continent. This also gives rise to another list called the "Eight Summits", which includes both Puncak Jaya and Mount Kosciuszko along with the six summits on the other continents.

This creates several possible versions of the seven summits:

• Everest, Aconcagua, Denali, Kilimanjaro, Vinson, Elbrus, Mount Wilhelm (Continent)
• Everest, Aconcagua, Denali, Kilimanjaro, Vinson, Elbrus, Kosciuszko (the Bass version)
• Everest, Aconcagua, Denali, Kilimanjaro, Vinson, Elbrus, Puncak Jaya (the Messner version)
• Everest, Aconcagua, Denali, Kilimanjaro, Vinson, Mont Blanc, Mount Wilhelm (the Wilhelm version)
• Everest, Aconcagua, Denali, Kilimanjaro, Vinson, Mont Blanc, Kosciuszko (the 1950s explorer Hackett version)
• Everest, Aconcagua, Denali, Kilimanjaro, Vinson, Mont Blanc, Puncak Jaya
• Everest, Aconcagua, Denali, Kilimanjaro, Vinson, Mauna Kea, Puncak Jaya / Kosciuszko (the tectonic version)

The concept Richard Bass and his climbing partner Frank Wells were pursuing was to be the first to stand atop the highest mountain on each continent. They pursued this goal as they defined it, climbing Aconcagua for South America, McKinley (now Denali) for North America, Kilimanjaro for Africa, Elbrus for Europe, Vinson for Antarctica, Kosciuszko for Australia, and finally Everest for Asia.

Definition using tectonic plates

Tectonic plates (see list of tectonic plates)

Using the largest tectonic plates, Asia and Europe could be grouped as Eurasia, and the very large Pacific Plate would have Mauna Kea as its highest mountain. Puncak Jaya is actually on the Maoke Plate, while Mount Wilhelm is on the Woodlark Plate, both of which are usually grouped with the larger Australian Plate. If not, then Mount Kosciuszko would revert to being the highest of that plate (see also list of highest points of Oceanian countries).

• African Plate – Kilimanjaro
• Antarctic Plate – Vinson
• Australian Plate – Puncak Jaya / Kosciuszko
• Eurasian Plate – Mount Everest
• North American Plate – Denali
• Pacific Plate – Mauna Kea
• South American Plate – Aconcagua

Australia

Mount Wilhelm

The highest mountain in mainland Australia is Mount Kosciuszko, 2,228 metres (7,310 ft) above sea level. However, the highest mountain on the Australian continent, which includes Australia and New Guinea, is Puncak Jaya, 4,884 m (16,024 ft) above sea level, in the Indonesian province of Papua and on the island of New Guinea, which shares the Sahul continental shelf with Australia. Mount Kosciuszko is easier to climb, being a four-hour, grade 3 return walk from the nearest car park, while Puncak Jaya is classed as a mountaineering expedition.

Some sources claim Mount Wilhelm (4,509 m (14,793 ft)) in Papua New Guinea's Bismarck Range (on the island of New Guinea, like Puncak Jaya) as the highest mountain on the Australian continent, on account of Indonesia being a part of Asia (see list of Southeast Asian mountains, which includes Puncak Jaya and other mountains in Western New Guinea, Indonesia). However, such a definition is political, not geophysical, and would mean that the western part of New Guinea changed continents in 1969.

In terms of Australia as a country, Mawson Peak (2,745 m (9,006 ft)) is higher than Kosciuszko. However, it is not located in Oceania, but on Heard Island, a small offshore island in the southern Indian Ocean. If excluding the island of New Guinea, then Aoraki / Mount Cook on the South Island of New Zealand is the highest mountain in Australasia at 3,724 m (12,218 ft).

Sources that list Mount Wilhelm as highest point in Oceania or show boundaries putting Puncak Jaya in Asia include: the United Nations, 7 Continent Summits, World Atlas, the CIA World Factbook, Canada Atlas, and Papua New Guinea PNG Trekking.

Europe

Mont Blanc summit

The generally accepted highest summit in Europe is Mount Elbrus (5,642 m or 18,510 ft) in the Caucasus, appearing on both the Bass and Messner lists. However, because the location of the boundary between Asia and Europe is not universally agreed upon, its inclusion in Europe is disputed: if the Kuma–Manych Depression is used as the geological border between Asia and Europe, the Caucasus and Elbrus lie wholly in Asia. If the Greater Caucasus watershed is used instead, Elbrus' peaks are wholly in Europe, albeit close to the border with Asia. Mont Blanc (4,810 m or 15,781 ft), lying on the border between France and Italy in the Graian Alps, is seen by some to be the highest mountain in Europe.

North America

Denali is the highest mountain peak in North America. The Caribbean Plate and the Panama Plate, both of which share geological processes with the North American continent, have their own highest mountain peaks:

• North America – Denali (6,194 m or 20,322 ft)
• Caribbean Plate – Acatenango Volcano (3,976 m or 13,045 ft)
• Panama Plate – Mount Chirripó (3,819 m or 12,530 ft)

South America

Chimborazo, farthest peak from the center of Earth and probably the greatest of the North Andes Plate

Aconcagua is the highest mountain peak in South America. The Altiplano Plate and the North Andes Plate, both of which share geological processes with the South American continent, have their own highest mountain peaks:

• South America – Aconcagua (6,961 m or 22,838 ft)
• Altiplano Plate – probably Nevado Sajama (6,542 m or 21,463 ft)
• North Andes Plate – Chimborazo (6,263 m or 20,548 ft)

The Bass and Messner lists

The first Seven Summits list as postulated by Bass (the Bass or Kosciusko list) chose the highest mountain of mainland Australia, Mount Kosciuszko (2,228 m or 7,310 ft), to represent the Australian continent's highest summit. Reinhold Messner postulated another list (the Messner or Carstensz list), replacing Mount Kosciuszko with Indonesia's Puncak Jaya, or Carstensz Pyramid (4,884 m or 16,024 ft). Neither the Bass nor the Messner list includes Mont Blanc. From a mountaineering point of view, the Messner list is the more challenging one. Climbing Carstensz Pyramid has the character of an expedition, whereas the ascent of Kosciuszko is an easy hike. Indeed, Patrick Morrow used this argument to defend his choice to adhere to the Messner list, "Being a climber first and a collector second, I felt strongly that Carstensz Pyramid, the highest mountain in Australasia ... was a true mountaineer’s objective."

Seven Summits (sorted by elevation)

Photograph	Peak	Bass list	Messner list	Hackett list	Elevation	Prominence	Continent	Mountain Range	Country	First ascent
	Mount Everest	✔	✔	✔	8,849 m (29,032 ft)	8,849 m (29,032 ft)	Asia	Himalayas	China Nepal	1953
	Aconcagua	✔	✔	✔	6,961 m (22,838 ft)	6,961 m (22,838 ft)	South America	Andes	Argentina	1897
	Denali	✔	✔	✔	6,194 m (20,322 ft)	6,144 m (20,157 ft)	North America	Alaska Range	United States	1913
	Kilimanjaro	✔	✔	✔	5,895 m (19,341 ft)	5,885 m (19,308 ft)	Africa	–	Tanzania	1889
	Mount Elbrus	✔	✔		5,642 m (18,510 ft)	4,741 m (15,554 ft)	Europe	Caucasus Mountains	Russia	1874
	Mount Vinson	✔	✔	✔	4,892 m (16,050 ft)	4,892 m (16,050 ft)	Antarctica	Sentinel Range	–	1966
	Puncak Jaya		✔		4,884 m (16,024 ft)	4,884 m (16,024 ft)	Australia	Sudirman Range	Indonesia	1962
	Mont Blanc			✔	4,810 m (15,781 ft)	4,696 m (15,407 ft)	Europe	Alps	France Italy	Unknown
	Mount Kosciuszko	✔		✔	2,228 m (7,310 ft)	2,228 m (7,310 ft)	Australia	Great Dividing Range	Australia	Unknown

Comparison of the heights of the Seven Summits with the eight-thousanders and the Seven Second Summits.

Comparison of the highest peaks of each continents

Mountaineering challenge

The mountaineering challenge to climb the Seven Summits is traditionally based on either the Bass or the Messner list. (It is assumed that most of the mountaineers who have completed the Seven Summits would have climbed Mont Blanc as well.) As of January 2010, approximately 275 climbers climbed all seven of the peaks from either the Bass or the Messner list; about 30% of those have climbed all of the eight peaks required to complete both lists.

History

Everest

In 1956, William D. Hackett (1918–1999), an American mountaineer, reached the top of five continents. He climbed Denali (then known as Mount McKinley) (1947), Aconcagua (1949), Kilimanjaro (1950), Kosciuszko (1956) and Mont Blanc (1956). In that time, Mont Blanc was considered to be the highest mountain of the European continent. Hackett made an attempt to climb Mount Vinson and obtained a permit for Mount Everest in 1960, but due to several circumstances (frostbite, lack of funds, etc.), he never made it to more than five summits.

In 1970, the Japanese mountaineer and adventurer Naomi Uemura (1941-1984) was the first person to reach five of the Seven Summits including Mount Everest. He climbed Mont Blanc (1966), Kilimanjaro (1966), Aconcagua (1968), Mount Everest (1970 solo) and Denali (1970 solo). After the first solo trip to the North Pole (1978), he planned to go on his own to Antarctica to climb Mount Vinson. In preparation for the Antarctica expedition, he did a solo winter ascent of Denali (1984). On the descent he disappeared in a winter storm.

In 1978, the Italian mountaineer Reinhold Messner was the first person to reach six of the Seven Summits (1971 Puncak Jaya, 1974 Aconcagua, 1976 Mount McKinley (now Denali), 1978 Kilimanjaro, 1978 Mount Everest). For Messner, Carstensz Pyramid (Puncak Jaya) was the highest peak in Australia (Messner list), but in 1983, he climbed Mount Kosciuszko to also satisfy the other geographic definition of Australia. In the same year, Messner climbed Mount Elbrus and declared that it was the true highest peak of Europe. This definition was quickly accepted by others in the mountaineering community. Finally in 1986, he climbed Mount Vinson. At that time, he was only the fifth person to reach the Seven Summits.

Mount Kosciuszko summit

In 1985, Richard Bass, a businessman and amateur mountaineer, was the first man to climb all Seven Summits. In only one year, 1983, he climbed six peaks: Aconcagua, Denali, Kilimanjaro, Mount Elbrus, Mount Vinson and Mount Kosciuszko. All of these climbs he did together with his companion Frank Wells and different mountain guides. Beginning in 1983, Bass and Wells made various guided attempts to climb Mount Everest, the highest and most difficult peak in the list. On 30 April 1985, Bass reached the summit of Mount Everest in a party without Wells, guided by the American professional mountaineer David Breashears. He then co-authored the book Seven Summits, which covered the undertaking. Later in 1985, American mountaineer Gerry Roach became the second person to climb the Seven Summits.

In 1986, the Canadian mountaineer Patrick Morrow became the first man to climb the Seven Summits in the Carstensz version (Messner list). He climbed Denali (1977), Aconcagua (1981), Mount Everest (1982), Kilimanjaro (1983), Mount Kosciuszko (1983), Mount Vinson (1985), Mount Elbrus (1985) and finally the Puncak Jaya (Carstensz Pyramid) on May 7, 1986. Morrow was also the first to complete both lists (Bass and Messner).

In 1990, Rob Hall and Gary Ball became the first to complete the "Seven Summits" in seven months. Using the Bass list, they started with Everest on 10 May 1990, and finished with Vinson on 12 December 1990, hours before the seven-month deadline.

In 1992, Junko Tabei became the first woman to complete the "Seven Summits". Mary "Dolly" Lefever became the first American woman to climb the "Seven Summits" on March 11, 1993, when she climbed Australia's Mount Kosciuszko. Earlier in 1993, she had become the oldest surviving woman to have reached the summit of Mount Everest; she was 47 years old. In January 1996, Chris Haver became the first American to climb and ski all seven summits. Yasuko Namba was famous in her native Japan for becoming the second Japanese woman to reach all of the Seven Summits including Everest, where she died during the storm of May 1996 during her descent.

A climber ascending Mount Vinson

In 2000, Croatian mountaineer Stipe Božić completed the Seven Summits. In May 2002, Susan Ershler and her husband, Phil, became the first married couple to climb the "Seven Summits" together. The first person to complete Seven Summits without the use of supplemental oxygen on Mount Everest is Reinhold Messner. Miroslav Caban is the second climber to finish the project without supplemental oxygen on Everest (finished in 2005 with Carstensz). Ed Viesturs also summitted all peaks without supplemental oxygen. Between 2002 and 2007, Austrian climber Christian Stangl completed the Seven Summits (Messner list), climbing alone and without supplemental oxygen, and reported a record total ascent time from respective base camp to summit of 58 hours and 45 minutes.

On 17 May 2006, Rhys Jones became the youngest person to complete the Seven Summits (Bass list) at the age of exactly 20 years. Notable climbers who had previously been the youngest to complete the Seven Summits include Rob Hall in 1990 and David Keaton in 1995. In May 2007, Samantha Larson completed the seven at the age of 18 years and 220 days (she is still the youngest woman to have climbed the Seven Summits). Johnny Strange finished climbing the summits at the age of 17 years and 161 days in June 2009. On 26 May 2011, at 6:45 Nepali time, Geordie Stewart became the youngest Briton to complete the Seven Summits at the age of 22 years and 21 days. In 2009-10, Indian mountaineer Krushnaa Patil made a bid for the fastest woman to complete the challenge; she fell short of the challenge when, in May 2009, her seventh and final summit bid on Denali was halted by her guide's illness. George Atkinson then became the youngest person in the world to complete the round aged 16 years 362 days. On 24 December 2011, the record was once again beaten, by American Jordan Romero, who completed the challenge at the age of 15 years, 5 months and 12 days by climbing Vinson.

In October 2006, Kit Deslauriers became the first person to have skied down (parts of) all seven peaks (Bass list). Three months later, in January 2007, Swedes Olof Sundström and Martin Letzter completed their Seven Summits skiing project by skiing down (parts of) Carstensz Pyramid, thus becoming the first and only people to have skied both lists.

Indian mountaineer Malli Mastan Babu also had the eminence of setting a Guinness world record by surmounting the Seven Summits in 172 days in 2006. The world record for completion of the Messner and Bass list was 136 days, by Danish climber Henrik Kristiansen in 2008. Kristiansen completed the summits in the following order: Vinson on Jan 21, Aconcagua on Feb 6, Kosciuszko on Feb 13, Kilimanjaro on Mar 1, Carstensz Pyramid on Mar 14, Elbrus on May 8, Everest on May 25, spending just 22 days on the mountain (normally, expeditions take up to two months acclimatizing, laying ropes, etc.) and finally Denali on June 5, beating Ian McKeever's previous record by 20 days. Vern Tejas set the new record for the same, in 134 days. Tejas began with summiting Vinson on 18 January 2010 and ended with summiting Denali on May 31. This was Tejas' ninth time to complete the Bass Seven Summits.

In January 2010, the Spanish climber Carlos Soria Fontán, at the age of 71, completed the seven summits (Messner list) after reaching the summit of Kilimanjaro. He had climbed the first one in 1968. On 23 May 2010, AC Sherpa summited Mount Everest as his last and final conquest of the Seven Summits (Bass list). In doing this, he set a new record by climbing the Seven Summits within 42 climbing days. Additionally, when climbing Mount Kilimanjaro (via Marangu) he summited in just 16 hours and 37 minutes, easily beating the previous record of 18 hours.

As of 24 December 2011, it is reported that only 118 people have climbed the Seven Summits if one assumes "full" completion of the quest requires climbing the "Eight Summits" across both the Bass and Messner lists (climbing both Carstensz Pyramid and Kosciusko in addition to the other six "undisputed" summits such as Everest). 231 persons have climbed the Messner list, while 234 have completed the Bass list. 348 have done either the Bass or Messner list.

In 2013, Vanessa O'Brien became the fastest female to complete the Seven Summits (including Carstensz Pyramid), finishing in 10 months. Cason Crane became the first openly gay man to climb the Seven Summits. On 21 November 2013, Werner Berger (Canada, ex-South African), at the age of 76 years and 129 days, became the oldest person in the world to complete the Seven Summits after a 6-day jungle trek to Carstensz Pyramid. In 2013, Cheryl and Nikki Bart became the first mother-daughter team to complete the Seven Summits.

On 16 December 2014, Tashi and Nungshi Malik became the world's first twins and siblings to complete the Seven Summits (Messner list). Colin O'Brady broke the record for the Messner and Bass lists in 131 days, summiting Vinson on 17 January 2016 and completing with Denali on 27 May 2016.

The youngest person to complete both the Seven Summits and the Volcanic Seven Summits is Satyarup Siddhanta from India. He completed the feat on 15 Jan 2019 after summitting Mt Sidley, Antarctica at the age of 35 years 261 days breaking the record of Daniel Bull from Australia . He was also the first Indian to accomplish the feat and created a Guinness world record.

On 6 January 2018, Chris Bombardier reached the summit of Mount Vinson, becoming the first person with hemophilia to complete the Seven Summits (Messner list). On 23 June 2018, Silvia Vasquez-Lavado reached the summit of Denali, becoming the first openly gay woman to complete the Seven Summits (including Carstensz Pyramid). On 4 January 2019, Arunima Sinha reached the summit of Mount Vinson, becoming the first female amputee to complete the Seven Summits (including Carstensz Pyramid).

Criticism

K2, about 800 feet (240 m) shorter than Everest

Alpinism author Jon Krakauer (1997) wrote in Into Thin Air that it would be a bigger challenge to climb the second-highest peak of each continent, known as the Seven Second Summits – a feat that was not accomplished until January 2013. This discussion had previously been published in an article titled The Second Seven Summits in Rock & Ice Magazine (#77) authored by the mountaineer and Seven Summits completer David Keaton. This is especially true for Asia, as K2 (8,611 m) demands greater technical climbing skills than Everest (8,848 m), while altitude-related factors such as the thinness of the atmosphere, high winds and low temperatures remain much the same. Some of those completing the seven ascents are aware of the magnitude of the challenge. In 2000, in a foreword to Steve Bell et al., Seven Summits, Morrow opined "[t]he only reason Reinhold [Messner] wasn’t the first person to complete the seven was that he was too busy gambolling up the 14 tallest mountains in the world."

Defence

Bill Allen, who completed the Seven Summits twice, said that getting to the summit never gets old. The 8000ers are all in East Asia; Nepal, China, India and Pakistan in a more narrow region of Earth, and many of the climbs are quite dangerous with several climbers dying short of completing all 14. Another problem is that while there are 14 main summits, there are additional sub-peaks over 8000 m. Indeed, in 2013, authorities were considering officially recognizing some additional peaks as 8000ers.

Impact and related climbing list concepts

Kanchenjunga is the world's third highest mountain ("K3"); it tops out less than 100 feet (30 m) shorter than K2.

One idea is to climb shorter peaks rather than the highest such as with the Seven Second Summits and Seven Third Summits. The Explorers Grand Slam includes the Seven Summits and both poles. Like the number one list, the number two and three lists is subject to the Bass vs. Messner geophysical/political dichotomy.

Number twos

• K2
• Ojos del Salado ("Eyes of Salt")
• Mount Logan
• Dykh-Tau ("Jagged Mount")
• Mount Kenya
• Mount Tyree
• Puncak Mandala (formerly "Juliana Peak")
• Mount Townsend

A Seven Second Summits collection was first achieved in January 2013 by Christian Stangl. It is considered to be a more difficult mountaineering challenge than the standard Seven Summits, even if the peaks are lower.

Mountain

From Wikipedia, the free encyclopedia

https://en.wikipedia.org/wiki/Mountain 

 

Mount Everest, Earth's highest mountain

A mountain is an elevated portion of the Earth's crust, generally with steep sides that show significant exposed bedrock. Although definitions vary, a mountain may differ from a plateau in having a limited summit area, and is usually higher than a hill, typically rising at least 300 metres (1,000 feet) above the surrounding land. A few mountains are isolated summits, but most occur in mountain ranges.

Mountains are formed through tectonic forces, erosion, or volcanism, which act on time scales of up to tens of millions of years. Once mountain building ceases, mountains are slowly leveled through the action of weathering, through slumping and other forms of mass wasting, as well as through erosion by rivers and glaciers.

High elevations on mountains produce colder climates than at sea level at similar latitude. These colder climates strongly affect the ecosystems of mountains: different elevations have different plants and animals. Because of the less hospitable terrain and climate, mountains tend to be used less for agriculture and more for resource extraction, such as mining and logging, along with recreation, such as mountain climbing and skiing.

The highest mountain on Earth is Mount Everest in the Himalayas of Asia, whose summit is 8,850 m (29,035 ft) above mean sea level. The highest known mountain on any planet in the Solar System is Olympus Mons on Mars at 21,171 m (69,459 ft).

Mount Kilimanjaro in Tanzania, Africa's highest mountain

Definition

Mount Elbrus, the highest mountain in Europe

 

Puncak Jaya in Indonesia, the highest mountain in Oceania

There is no universally accepted definition of a mountain. Elevation, volume, relief, steepness, spacing and continuity have been used as criteria for defining a mountain. In the Oxford English Dictionary a mountain is defined as "a natural elevation of the earth surface rising more or less abruptly from the surrounding level and attaining an altitude which, relatively to the adjacent elevation, is impressive or notable."

Whether a landform is called a mountain may depend on local usage. Mount Scott outside Lawton, Oklahoma, US, is only 251 m (823 ft) from its base to its highest point. John Whittow's Dictionary of Physical Geography states "Some authorities regard eminences above 600 metres (1,969 ft) as mountains, those below being referred to as hills."

In the United Kingdom and the Republic of Ireland, a mountain is usually defined as any summit at least 2,000 feet (610 m) high, which accords with the official UK government's definition that a mountain, for the purposes of access, is a summit of 2,000 feet (610 m) or higher. In addition, some definitions also include a topographical prominence requirement, such as that the mountain rises 300 metres (984 ft) above the surrounding terrain. At one time the US Board on Geographic Names defined a mountain as being 1,000 feet (305 m) or taller, but has abandoned the definition since the 1970s. Any similar landform lower than this height was considered a hill. However, today, the US Geological Survey concludes that these terms do not have technical definitions in the US.

The UN Environmental Programme's definition of "mountainous environment" includes any of the following:

• Class 1: Elevation greater than 4,500 m (14,764 ft).
• Class 2: Elevation between 3,500 m (11,483 ft) and 4,500 m (14,764 ft).
• Class 3: Elevation between 2,500 m (8,202 ft) and 3,500 m (11,483 ft).
• Class 4: Elevation between 1,500 m (4,921 ft) and 2,500 m (8,202 ft), with a slope greater than 2 degrees.
• Class 5: Elevation between 1,000 m (3,281 ft) and 1,500 m (4,921 ft), with a slope greater than 5 degrees and/or 300 m (984 ft) elevation range within 7 km (4.3 mi).
• Class 6: Elevation between 300 m (984 ft) and 1,000 m (3,281 ft), with a 300 m (984 ft) elevation range within 7 km (4.3 mi).
• Class 7: Isolated inner basins and plateaus less than 25 km² (9.7 sq mi) in area that are completely surrounded by Class 1 to 6 mountains, but do not themselves meet criteria for Class 1 to 6 mountains.

Using these definitions, mountains cover 33% of Eurasia, 19% of South America, 24% of North America, and 14% of Africa. As a whole, 24% of the Earth's land mass is mountainous.

Geology

Main articles: Mountain formation and List of mountain types

There are three main types of mountains: volcanic, fold, and block. All three types are formed from plate tectonics: when portions of the Earth's crust move, crumple, and dive. Compressional forces, isostatic uplift and intrusion of igneous matter forces surface rock upward, creating a landform higher than the surrounding features. The height of the feature makes it either a hill or, if higher and steeper, a mountain. Major mountains tend to occur in long linear arcs, indicating tectonic plate boundaries and activity.

Volcanoes

Main article: Volcano

 

Fuji volcano

Volcanoes are formed when a plate is pushed below another plate, or at a mid-ocean ridge or hotspot. At a depth of around 100 km (60 mi), melting occurs in rock above the slab (due to the addition of water), and forms magma that reaches the surface. When the magma reaches the surface, it often builds a volcanic mountain, such as a shield volcano or a stratovolcano. Examples of volcanoes include Mount Fuji in Japan and Mount Pinatubo in the Philippines. The magma does not have to reach the surface in order to create a mountain: magma that solidifies below ground can still form dome mountains, such as Navajo Mountain in the US.

Fold mountains

Main article: Fold mountains

 

Illustration of mountains that developed on a fold that has been thrust

Fold mountains occur when two plates collide: shortening occurs along thrust faults and the crust is overthickened. Since the less dense continental crust "floats" on the denser mantle rocks beneath, the weight of any crustal material forced upward to form hills, plateaus or mountains must be balanced by the buoyancy force of a much greater volume forced downward into the mantle. Thus the continental crust is normally much thicker under mountains, compared to lower lying areas. Rock can fold either symmetrically or asymmetrically. The upfolds are anticlines and the downfolds are synclines: in asymmetric folding there may also be recumbent and overturned folds. The Balkan Mountains and the Jura Mountains are examples of fold mountains.

Block mountains

Main article: Block mountains

 

Pirin Mountain, Bulgaria, part of the fault-block Rila-Rhodope massif

Block mountains are caused by faults in the crust: a plane where rocks have moved past each other. When rocks on one side of a fault rise relative to the other, it can form a mountain. The uplifted blocks are block mountains or horsts. The intervening dropped blocks are termed graben: these can be small or form extensive rift valley systems. This form of landscape can be seen in East Africa, the Vosges and Rhine valley, and the Basin and Range Province of Western North America. These areas often occur when the regional stress is extensional and the crust is thinned.

Erosion

Main article: Erosion

 

The Catskills in Upstate New York represent an eroded plateau.

During and following uplift, mountains are subjected to the agents of erosion (water, wind, ice, and gravity) which gradually wear the uplifted area down. Erosion causes the surface of mountains to be younger than the rocks that form the mountains themselves. Glacial processes produce characteristic landforms, such as pyramidal peaks, knife-edge arêtes, and bowl-shaped cirques that can contain lakes. Plateau mountains, such as the Catskills, are formed from the erosion of an uplifted plateau.

Climate

Main article: Alpine climate

 

The northern Urals at high latitude and elevation have an alpine climate and barren ground.

Climate in the mountains becomes colder at high elevations, due to an interaction between radiation and convection. Sunlight in the visible spectrum hits the ground and heats it. The ground then heats the air at the surface. If radiation were the only way to transfer heat from the ground to space, the greenhouse effect of gases in the atmosphere would keep the ground at roughly 333 K (60 °C; 140 °F), and the temperature would decay exponentially with height.

However, when air is hot, it tends to expand, which lowers its density. Thus, hot air tends to rise and transfer heat upward. This is the process of convection. Convection comes to equilibrium when a parcel of air at a given altitude has the same density as its surroundings. Air is a poor conductor of heat, so a parcel of air will rise and fall without exchanging heat. This is known as an adiabatic process, which has a characteristic pressure-temperature dependence. As the pressure gets lower, the temperature decreases. The rate of decrease of temperature with elevation is known as the adiabatic lapse rate, which is approximately 9.8 °C per kilometre (or 5.4 °F (3.0 °C) per 1000 feet) of altitude.

The presence of water in the atmosphere complicates the process of convection. Water vapor contains latent heat of vaporization. As air rises and cools, it eventually becomes saturated and cannot hold its quantity of water vapor. The water vapor condenses (forming clouds), and releases heat, which changes the lapse rate from the dry adiabatic lapse rate to the moist adiabatic lapse rate (5.5 °C per kilometre or 3 °F (1.7 °C) per 1000 feet) The actual lapse rate can vary by altitude and by location. Therefore, moving up 100 m (330 ft) on a mountain is roughly equivalent to moving 80 kilometres (45 miles or 0.75° of latitude) towards the nearest pole. This relationship is only approximate, however, since local factors such as proximity to oceans (such as the Arctic Ocean) can drastically modify the climate. As the altitude increases, the main form of precipitation becomes snow and the winds increase.

The effect of the climate on the ecology at an elevation can be largely captured through a combination of amount of precipitation, and the biotemperature, as described by Leslie Holdridge in 1947. Biotemperature is the mean temperature; all temperatures below 0 °C (32 °F) are considered to be 0 °C. When the temperature is below 0 °C, plants are dormant, so the exact temperature is unimportant. The peaks of mountains with permanent snow can have a biotemperature below 1.5 °C (34.7 °F).

Climate change

Mountain environments are particularly sensitive to anthropogenic climate change and are currently undergoing alterations unprecedented in last 10,000 years. In recent decades mountain ice caps and glaciers have experienced accelerating ice loss. The melting of the glaciers, permafrost and snow has caused underlying surfaces to become increasingly unstable. Landslip hazards have increased in both number and magnitude due to climate change.

Alpine ecosystems can also thus be particularly climatically sensitive. Many mid-latitude mountains act as cold climate refugia, with the ecosystems occupying small environmental niches. As well as the direct influence that the change in climate can have on an ecosystem, there is also the indirect one on the soils from changes in stability and soil development.

Patterns of river discharge are also significantly affected by climate change, which in turn has significant impacts on communities that rely on water fed from alpine sources. Nearly half of mountain areas provide essential or supportive water resources for mainly urban populations, in particular during the dry season and in semiarid areas such as in central Asia.

Ecology

Main article: Montane ecology

 

An alpine mire in the Swiss Alps

The colder climate on mountains affects the plants and animals residing on mountains. A particular set of plants and animals tend to be adapted to a relatively narrow range of climate. Thus, ecosystems tend to lie along elevation bands of roughly constant climate. This is called altitudinal zonation. In regions with dry climates, the tendency of mountains to have higher precipitation as well as lower temperatures also provides for varying conditions, which enhances zonation.

Some plants and animals found in altitudinal zones tend to become isolated since the conditions above and below a particular zone will be inhospitable and thus constrain their movements or dispersal. These isolated ecological systems are known as sky islands.

Altitudinal zones tend to follow a typical pattern. At the highest elevations, trees cannot grow, and whatever life may be present will be of the alpine type, resembling tundra. Just below the tree line, one may find subalpine forests of needleleaf trees, which can withstand cold, dry conditions. Below that, montane forests grow. In the temperate portions of the earth, those forests tend to be needleleaf trees, while in the tropics, they can be broadleaf trees growing in a rain forest.

Mountains and humans

See also: List of highest cities in the world

The highest known permanently tolerable altitude is at 5,950 metres (19,520 ft). At very high altitudes, the decreasing atmospheric pressure means that less oxygen is available for breathing, and there is less protection against solar radiation (UV). Above 8,000 metres (26,000 ft) elevation, there is not enough oxygen to support human life. This is sometimes referred to as the "death zone". The summits of Mount Everest and K2 are in the death zone.

Mountain societies and economies

Mountains are generally less preferable for human habitation than lowlands, because of harsh weather and little level ground suitable for agriculture. While 7% of the land area of Earth is above 2,500 metres (8,200 ft), only 140 million people live above that altitude and only 20-30 million people above 3,000 metres (9,800 ft) elevation. About half of mountain dwellers live in the Andes, Central Asia, and Africa.

The city of La Paz reaches up to 4,000 metres (13,000 ft) in elevation.

With limited access to infrastructure, only a handful of human communities exist above 4,000 metres (13,000 ft) of elevation. Many are small and have heavily specialized economies, often relying on industries such as agriculture, mining, and tourism. An example of such a specialized town is La Rinconada, Peru, a gold-mining town and the highest elevation human habitation at 5,100 metres (16,700 ft). A counterexample is El Alto, Bolivia, at 4,150 metres (13,620 ft), which has a highly diverse service and manufacturing economy and a population of nearly 1 million.

Traditional mountain societies rely on agriculture, with higher risk of crop failure than at lower elevations. Minerals often occur in mountains, with mining being an important component of the economics of some montane societies. More recently, tourism supports mountain communities, with some intensive development around attractions such as national parks or ski resorts. About 80% of mountain people live below the poverty line.

Most of the world's rivers are fed from mountain sources, with snow acting as a storage mechanism for downstream users. More than half of humanity depends on mountains for water.

In geopolitics mountains are often seen as preferable "natural boundaries" between polities.

Mountaineering

Main article: Mountaineering

 

Mountaineers climbing in South Tyrol

Mountain climbing, or alpinism is the sport, hobby or profession of hiking, skiing, and climbing mountains. While mountaineering began as attempts to reach the highest point of unclimbed big mountains it has branched into specializations that address different aspects of the mountain and consists of three areas: rock-craft, snow-craft and skiing, depending on whether the route chosen is over rock, snow or ice. All require experience, athletic ability, and technical knowledge of the terrain to maintain safety.

Mountains as sacred places

Main article: Sacred mountains

Mountains often play a significant role in religion. There are for example a number of sacred mountains within Greece such as Mount Olympus which was held to be the home of the gods. In Japanese culture, the 3,776.24 m (12,389 ft) volcano of Mount Fuji is also held to be sacred with tens of thousands of Japanese ascending it each year. Mount Kailash, in the Tibet Autonomous Region of China, is considered to be sacred in four religions: Hinduism, Bon, Buddhism, and Jainism. In Ireland, pilgrimages are made up the 952 metres (3,123 ft) Mount Brandon by Irish Catholics. The Himalayan peak of Nanda Devi is associated with the Hindu goddesses Nanda and Sunanda; it has been off-limits to climbers since 1983. Mount Ararat is a sacred mountain, as it is believed to be the landing place of Noah's Ark. In Europe and especially in the Alps, summit crosses are often erected on the tops of prominent mountains.

Superlatives

Main article: List of highest mountains

 

Chimborazo, Ecuador. The point on Earth's surface farthest from its centre.

Heights of mountains are typically measured above sea level. Using this metric, Mount Everest is the highest mountain on Earth, at 8,848 metres (29,029 ft). There are at least 100 mountains with heights of over 7,200 metres (23,622 ft) above sea level, all of which are located in central and southern Asia. The highest mountains above sea level are generally not the highest above the surrounding terrain. There is no precise definition of surrounding base, but Denali, Mount Kilimanjaro and Nanga Parbat are possible candidates for the tallest mountain on land by this measure. The bases of mountain islands are below sea level, and given this consideration Mauna Kea (4,207 m (13,802 ft) above sea level) is the world's tallest mountain and volcano, rising about 10,203 m (33,474 ft) from the Pacific Ocean floor.

The highest mountains are not generally the most voluminous. Mauna Loa (4,169 m or 13,678 ft) is the largest mountain on Earth in terms of base area (about 2,000 sq mi or 5,200 km²) and volume (about 18,000 cu mi or 75,000 km³). Mount Kilimanjaro is the largest non-shield volcano in terms of both base area (245 sq mi or 635 km²) and volume (1,150 cu mi or 4,793 km³). Mount Logan is the largest non-volcanic mountain in base area (120 sq mi or 311 km²).

The highest mountains above sea level are also not those with peaks farthest from the centre of the Earth, because the figure of the Earth is not spherical. Sea level closer to the equator is several miles farther from the centre of the Earth. The summit of Chimborazo, Ecuador's tallest mountain, is usually considered to be the farthest point from the Earth's centre, although the southern summit of Peru's tallest mountain, Huascarán, is another contender. Both have elevations above sea level more than 2 kilometres (6,600 ft) less than that of Everest.