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72-668: Ellhorn is a mountain in Switzerland on the Rätikon mountain range on the Central Eastern Alps , located on the border with Liechtenstein . It has an elevation 758 metres (2,487 ft) above sea level. The mountain was historically part of Liechtenstein, in the municipality of Balzers . In the 1930s, Swiss military planners became concerned that the territory made fortifications in Fläsch vulnerable. This concern

144-428: A biotemperature below 1.5 °C (34.7 °F). Mountain environments are particularly sensitive to anthropogenic climate change and are currently undergoing alterations unprecedented in last 10,000 years. The effect of global warming on mountain regions (relative to lowlands) is still an active area of study. Observational studies show that highlands are warming faster than nearby lowlands, but when compared globally,

216-423: A central trough of molten, flowing lava. Partially collapsed lava tubes are visible as chains of pit craters, and broad lava fans formed by lava emerging from intact, subsurface tubes are also common. In places along the volcano's base, solidified lava flows can be seen spilling out into the surrounding plains, forming broad aprons, and burying the basal escarpment. Crater counts from high-resolution images taken by

288-466: A depth of about 32 km (105,000 ft) below the caldera floor. Crater size-frequency distributions on the caldera floors indicate the calderas range in age from 350 Mya to about 150 Mya. All probably formed within 100 million years of each other. It is possible that the magma chambers within Olympus Mons received new magma from the mantle after the caldera floors formed, leading to

360-500: A feature unique among the shield volcanoes of Mars, which may have been created by enormous flank landslides . Olympus Mons covers an area of about 300,000 km (120,000 sq mi), which is approximately the size of Italy or the Philippines , and it is supported by a 70 km (43 mi) thick lithosphere . The extraordinary size of Olympus Mons is likely because Mars lacks mobile tectonic plates . Unlike on Earth,

432-464: 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

504-430: A number of wrinkle ridges located at the basal escarpment. Why opposite sides of the mountain should show different styles of deformation may lie in how large shield volcanoes grow laterally and in how variations within the volcanic substrate have affected the mountain's final shape. Large shield volcanoes grow not only by adding material to their flanks as erupted lava, but also by spreading laterally at their bases. As

576-648: 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 (12,389.2 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

648-418: A volcano grows in size, the stress field underneath the volcano changes from compressional to extensional. A subterranean rift may develop at the base of the volcano, causing the underlying crust to spread apart. If the volcano rests on sediments containing mechanically weak layers (e.g., beds of water-saturated clay), detachment zones ( décollements ) may develop in the weak layers. The extensional stresses in

720-471: A whole, 24% of the Earth's land mass is mountainous. 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

792-452: 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 mountain-based societies. More recently, tourism has become more important to

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864-571: 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). The tallest mountain including submarine terrain is Mauna Kea in Hawaii from its underwater base at 9,330 m (30,610 ft) and some scientists consider it to be

936-478: 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

1008-419: Is a set of outdoor activities that involves ascending mountains . Mountaineering-related activities include traditional outdoor climbing , skiing , and traversing via ferratas that have become sports in their own right. Indoor climbing , sport climbing , and bouldering are also considered variants of mountaineering by some, but are part of a wide group of mountain sports . Mountains often play

1080-482: Is about 600 km (370 mi) wide. Because the mountain is so large, with complex structure at its edges, allocating a height to it is difficult. Olympus Mons stands 21 km (13 mi) above the Mars global datum , and its local relief, from the foot of the cliffs which form its northwest margin to its peak, is over 21 km (13 mi) (a little over twice the height of Mauna Kea as measured from its base on

1152-488: Is expansive and does not drop off in density with height as sharply as Earth's. The composition of Olympus Mons is approximately 44% silicates , 17.5% iron oxides (which give the planet its red coloration), 7% aluminium , 6% magnesium , 6% calcium , and particularly high proportions of sulfur dioxide with 7%. These results point to the surface being largely composed of basalts and other mafic rocks, which would have erupted as low viscosity lava flows and hence lead to

1224-556: 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. 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

1296-457: 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

1368-525: Is the largest mountain on Earth in terms of base area (about 2,000 sq mi or 5,200 km ) and volume (about 18,000 cu mi or 75,000 km ). Mount Kilimanjaro is the largest non-shield volcano in terms of both base area (245 sq mi or 635 km ) and volume (1,150 cu mi or 4,793 km ). Mount Logan is the largest non-volcanic mountain in base area (120 sq mi or 311 km ). The highest mountains above sea level are also not those with peaks farthest from

1440-606: Is the youngest of the large volcanoes on Mars, having formed during the Martian Hesperian Period with eruptions continuing well into the Amazonian Period . It has been known to astronomers since the late 19th century as the albedo feature Nix Olympica (Latin for "Olympic Snow"), and its mountainous nature was suspected well before space probes confirmed it as a mountain. Two impact craters on Olympus Mons have been assigned provisional names by

1512-526: The Andes , Central Asia, and Africa. 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

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1584-649: The Basin and Range Province of Western North America. These areas often occur when the regional stress is extensional and the crust is thinned. 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

1656-468: The Catskills , are formed from the erosion of an uplifted plateau. 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

1728-559: The International Astronomical Union : the 15.6-kilometre-diameter (9.7 mi) Karzok crater and the 10.4-kilometre-diameter (6.5 mi) Pangboche crater . They are two of several suspected source areas for shergottites , the most abundant class of Martian meteorites . As a shield volcano , Olympus Mons resembles the shape of the large volcanoes making up the Hawaiian Islands . The edifice

1800-587: The Mars Express orbiter in 2004 indicate that lava flows on the northwestern flank of Olympus Mons range in age from 115 million years old (Mya) to only 2 Mya. These ages are very recent in geological terms, suggesting that the mountain may still be volcanically active, though in a very quiescent and episodic fashion. The caldera complex at the peak of the volcano is made of at least six overlapping calderas and caldera segments (pictured). Calderas are formed by roof collapse following depletion and withdrawal of

1872-405: The 19th century. The astronomer Patrick Moore pointed out that Schiaparelli (1835–1910) "had found that his Nodus Gordis and Olympic Snow [Nix Olympica] were almost the only features to be seen" during dust storms, and "guessed correctly that they must be high". The Mariner 9 spacecraft arrived in orbit around Mars in 1971 during a global dust-storm. The first objects to become visible as

1944-621: 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. Heights of mountains are typically measured above sea level . Using this metric, Mount Everest

2016-457: The Tharsis rise, which presented a higher-friction zone at the volcano's base. Friction was higher in that direction because the sediments were thinner and probably consisted of coarser grained material resistant to sliding. The competent and rugged basement rocks of Tharsis acted as an additional source of friction. This inhibition of southeasterly basal spreading in Olympus Mons could account for

2088-455: The US. 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

2160-622: 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

2232-581: The adjacent elevation, is impressive or notable." Whether a landform is called a mountain may depend on local usage. 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

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2304-805: The area to include the Ellhorn mountain. 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 (980  ft ) 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

2376-553: 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 to form 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

2448-429: 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

2520-461: The atmospheric pressure at the summit of Mount Everest is 32,000 pascals, or about 32% of Earth's sea level pressure. Even so, high-altitude orographic clouds frequently drift over the Olympus Mons summit, and airborne Martian dust is still present. Although the average Martian surface atmospheric pressure is less than one percent of Earth's, the much lower gravity of Mars increases the atmosphere's scale height ; in other words, Mars's atmosphere

2592-467: The base of Olympus Mons and is thought to be due to the volcano's immense weight pressing down on the Martian crust. The depth of this depression is greater on the northwest side of the mountain than on the southeast side. Olympus Mons is partially surrounded by a region of distinctive grooved or corrugated terrain known as the Olympus Mons aureole. The aureole consists of several large lobes. Northwest of

2664-524: 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. Olympus Mons Olympus Mons

2736-459: 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

2808-534: 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

2880-476: 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 are caused by faults in

2952-458: The crust of Mars remains fixed over a stationary hotspot , and a volcano can continue to discharge lava until it reaches an enormous height. Being a shield volcano, Olympus Mons has a very gently sloping profile. The average slope on the volcano's flanks is only 5%. Slopes are steepest near the middle part of the flanks and grow shallower toward the base, giving the flanks a concave upward profile. Its flanks are shallower and extend farther from

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3024-513: 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 kind of landscape can be seen in East Africa , the Vosges and Rhine valley, and

3096-548: The definition since the 1970s. Any similar landform lower than this height was considered a hill. However, today, the United States 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: Using these definitions, mountains cover 33% of Eurasia, 19% of South America, 24% of North America, and 14% of Africa. As

3168-408: The detachment zones can produce giant landslides and normal faults on the volcano's flanks, leading to the formation of a basal escarpment. Further from the volcano, these detachment zones can express themselves as a succession of overlapping, gravity driven thrust faults. This mechanism has long been cited as an explanation of the Olympus Mons aureole deposits (discussed below). Olympus Mons lies at

3240-460: The dry season and in semiarid areas such as in central Asia. Alpine ecosystems can 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. The colder climate on mountains affects

3312-409: The dust began to settle, the tops of the Tharsis volcanoes, demonstrated that the altitude of these features greatly exceeded that of any mountain found on Earth, as astronomers expected. Observations of the planet from Mariner 9 confirmed that Nix Olympica was a volcano. Ultimately, astronomers adopted the name Olympus Mons for the albedo feature known as Nix Olympica. Olympus Mons is located between

3384-523: The economies of mountain communities, with developments focused around attractions such as national parks and ski resorts . Approximately 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 natural boundaries between polities. Mountaineering , mountain climbing, or alpinism

3456-708: The edge of the Tharsis bulge, an ancient vast volcanic plateau likely formed by the end of the Noachian Period . During the Hesperian , when Olympus Mons began to form, the volcano was located on a shallow slope that descended from the high in Tharsis into the northern lowland basins. Over time, these basins received large volumes of sediment eroded from Tharsis and the southern highlands. The sediments likely contained abundant Noachian-aged phyllosilicates (clays) formed during an early period on Mars when surface water

3528-428: The effect disappears. Precipitation in highland areas is not increasing as quickly as in lowland areas. Climate modeling give mixed signals about whether a particular highland area will have increased or decreased precipitation. Climate change has started to affect the physical and ecological systems of mountains. In recent decades mountain ice caps and glaciers have experienced accelerating ice loss. The melting of

3600-433: 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 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

3672-498: 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. Patterns of river discharge will also be significantly affected by climate change, which in turn will have 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

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3744-450: The inflation of each chamber and uplift of parts of the volcano summit. Olympus Mons is structurally and topographically asymmetrical. The longer, more shallow northwestern flank displays extensional features, such as large slumps and normal faults . In contrast, the volcano's steeper southeastern side has features indicating compression, including step-like terraces in the volcano's mid-flank region (interpreted as thrust faults ) and

3816-528: The loss of territory, with either a transfer of Swiss land elsewhere or greater banking cooperation between the two countries. The transfer faced resistance from the residents in Balzers, and was not supported by Franz Joseph II , the ruling Prince of Liechtenstein . In addition to unofficial objections from Nazi Germany, the lack of support forced Hoop to end negotiations with Switzerland. Following World War II , Switzerland once again pressed Liechtenstein for

3888-421: The low gradients on the surface of the planet. Olympus Mons is the result of many thousands of highly fluid, basaltic lava flows that poured from volcanic vents over a long period of time (the Hawaiian Islands exemplify similar shield volcanoes on a smaller scale – see Mauna Kea ). Like the basalt volcanoes on Earth, Martian basaltic volcanoes are capable of erupting enormous quantities of ash . Due to

3960-487: The northwestern edge of the Tharsis region and the eastern edge of Amazonis Planitia . It stands about 1,200 km (750 mi) from the other three large Martian shield volcanoes, collectively called the Tharsis Montes ( Arsia Mons , Pavonis Mons , and Ascraeus Mons ). The Tharsis Montes are slightly smaller than Olympus Mons. A wide, annular depression or moat about 2 km (1.2 mi) deep surrounds

4032-538: The ocean floor). The total elevation change from the plains of Amazonis Planitia , over 1,000 km (620 mi) to the northwest, to the summit approaches 26 km (16 mi). The summit of the mountain has six nested calderas (collapsed craters) forming an irregular depression 60 km (37 mi) × 80 km (50 mi) across and up to 3.2 km (2.0 mi) deep. The volcano's outer edge consists of an escarpment , or cliff, up to 8 km (5.0 mi) tall (although obscured by lava flows in places),

4104-520: 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 United States Board on Geographic Names defined a mountain as being 1,000 feet (305 m) or taller, but has abandoned

4176-527: 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

4248-418: The reduced gravity of Mars compared to Earth, there are lesser buoyant forces on the magma rising out of the crust. In addition, the magma chambers are thought to be much larger and deeper than the ones found on Earth. The flanks of Olympus Mons are made up of innumerable lava flows and channels. Many of the flows have levees along their margins (pictured). The cooler, outer margins of the flow solidify, leaving

4320-513: The structural and topographic asymmetry of the mountain. Numerical models of particle dynamics involving lateral differences in friction along the base of Olympus Mons have been shown to reproduce the volcano's present shape and asymmetry fairly well. It has been speculated that the detachment along the weak layers was aided by the presence of high-pressure water in the sediment pore spaces, which would have interesting astrobiological implications. If water-saturated zones still exist in sediments under

4392-412: The subsurface magma chamber after an eruption. Each caldera thus represents a separate pulse of volcanic activity on the mountain. The largest and oldest caldera segment appears to have formed as a single, large lava lake. Using geometric relationships of caldera dimensions from laboratory models, scientists have estimated that the magma chamber associated with the largest caldera on Olympus Mons lies at

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4464-411: The summit in the northwestern direction than they do to the southeast. The volcano's shape and profile have been likened to a "circus tent" held up by a single pole that is shifted off center. Due to the size and shallow slopes of Olympus Mons, an observer standing on the Martian surface would be unable to view the entire profile of the volcano, even from a great distance. The curvature of the planet and

4536-514: 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

4608-477: 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)

4680-481: The tallest on earth. 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

4752-473: 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 rainforest . 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

4824-602: The transfer of Ellhorn. Switzerland threatened to, among other things, end the customs union between the two countries which had existed since 1924. Despite the community in Balzers again objecting in November 1948, the transfer was approved by the Landtag of Liechtenstein the following month and finalised in 1949. In exchange for the transfer, Switzerland agreed to forgive much of Liechtenstein's debt incurred during World War II. In 1952, Switzerland expanded its fortifications in

4896-453: The volcano itself would obscure such a synoptic view. Similarly, an observer near the summit would be unaware of standing on a very high mountain, as the slope of the volcano would extend far beyond the horizon, a mere 3 kilometers away. The typical atmospheric pressure at the top of Olympus Mons is 72 pascals , about 12% of the average Martian surface pressure of 600 pascals. Both are exceedingly low by terrestrial standards; by comparison,

4968-414: The volcano, the aureole extends a distance of up to 750 km (470 mi) and is known as Lycus Sulci ( 24°36′N 219°00′E  /  24.600°N 219.000°E  / 24.600; 219.000 ). East of Olympus Mons, the aureole is partially covered by lava flows, but where it is exposed it goes by different names ( Gigas Sulci , for example). The origin of the aureole remains debated, but it

5040-419: The volcano, they would likely have been kept warm by a high geothermal gradient and residual heat from the volcano's magma chamber. Potential springs or seeps around the volcano would offer many possibilities for detecting microbial life. Olympus Mons and a few other volcanoes in the Tharsis region stand high enough to reach above the frequent Martian dust-storms recorded by telescopic observers as early as

5112-416: Was abundant, and were thickest in the northwest where basin depth was greatest. As the volcano grew through lateral spreading, low-friction detachment zones preferentially developed in the thicker sediment layers to the northwest, creating the basal escarpment and widespread lobes of aureole material ( Lycus Sulci ). Spreading also occurred to the southeast; however, it was more constrained in that direction by

5184-599: Was heightened by perceptions that Liechtenstein was susceptible to annexation into Nazi Germany in the wake of the Anschluss of Austria . In 1938, the Swiss Federal Council began negotiations with Liechtenstein to cede the Ellhorn mountain to them. Though Josef Hoop , the Prime Minister of Liechtenstein , was supportive of the transfer, he argued that the country should be fairly compensated for

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