mountain

Share on Facebook Share on Twitter Email
(moun'tən) pronunciation
n.
  1. (Abbr. Mt. or Mtn.) A natural elevation of the earth's surface having considerable mass, generally steep sides, and a height greater than that of a hill.
    1. A large heap: a mountain of laundry.
    2. A huge quantity: a mountain of trouble.

[Middle English mountaine, from Old French montaigne, muntaigne, from Vulgar Latin *montānea, from feminine of *montāneus, of a mountain, from Latin montānus, from mōns, mont-, mountain.]

mountainy moun'tain·y adj.


K2 (Mount Godwin Austen), in the Karakoram Range, viewed from the Gilgit-Baltistan district of the
(click to enlarge)
K2 (Mount Godwin Austen), in the Karakoram Range, viewed from the Gilgit-Baltistan district of the
Landform that rises well above its surroundings, generally exhibiting steep slopes, a relatively confined summit area, and considerable local relief (inequalities of elevation). Mountains are considered larger than hills, but the term has no standardized geologic meaning. Mountains are formed by the folding, faulting, or upwarping of the Earth's surface due to the movement of plates ( plate tectonics) or by the emplacement of volcanic rock onto the surface. For example, the Himalayan Mountains where India meets the Eurasian Plate were formed by a collision between plates that caused extreme compressional folding and the uplifting of large areas. The mountain ranges around the Pacific basin are attributed to the sinking of one plate beneath another. plateau.

For more information on mountain, visit Britannica.com.

Concept

Among the most striking of geologic features are mountains, created by several types of tectonic forces, including collisions between continental masses. Mountains have long had an impact on the human psyche, for instance by virtue of their association with the divine in the Greek myths, the Bible, and other religious or cultural traditions. One does not need to be a geologist to know what a mountain is; indeed there is no precise definition of mountain, though in most cases the distinction between a mountain and a hill is fairly obvious. On the other hand, the defining characteristics of a volcano are more apparent. Created by violent tectonic forces, a volcano usually is considered a mountain, and almost certainly is one after it erupts, pouring out molten rock and other substances from deep in the earth.

How It Works

Plate Tectonics

Earth is constantly moving, driven by forces beneath its surface. The interior of Earth itself is divided into three major sections: the crust, mantle, and core. The lithosphere is the upper layer of Earth's interior, including the crust and the brittle portion at the top of the mantle. Tectonism is the deformation of the lithosphere, and the term tectonics refers to the study of this deformation. Most notable among examples of tectonic deformation is mountain building, or orogenesis, discussed later in this essay.

The planet's crust is not all of one piece: it is composed of numerous plates, which are steadily moving in relation to one another. This movement is responsible for all manner of phenomena, including earthquakes, volcanoes, and mountain building. All these ideas and many more are encompassed in the concept of plate tectonics, which is the name for a branch of geologic and geophysical study and of a dominant principle often described as "the unifying theory of geology" (see Plate Tectonics).

Contents Under Pressure

Tectonism results from the release and redistribution of energy from Earth's interior. This energy is either gravitational, and thus a function of the enormous mass at the planet's core, or thermal, resulting from the heat generated by radioactive decay. Differences in mass and heat within the planet's interior, known as pressure gradients, result in the deformation of rocks, placing many forms of stress and strain on them.

In scientific terms, stress is any attempt to deform an object, and strain is a change in dimension resulting from stress. Rocks experience stress in the form of tension, compression, and shear. Tension acts to stretch a material, whereas compression is a form of stress produced by the action of equal and opposite forces, whose effect is to reduce the length of a material. (Compression is a form of pressure.) Shear results from equal and opposite forces that do not act along the same plane. If a thick, hardbound book is lying flat, and one pushes the front cover from the side so that the covers and pages are no longer in alignment, is an example of shear.

Rocks manifest the strain resulting from these stresses by warping, sliding, or breaking. They may even flow, as though they were liquids, or melt and thus truly become liquid. As a result, Earth's interior may manifest faults, or fractures in rocks, as well as folds, or bends in the rock structure. The effects can be seen on the surface in the form of subsidence, which is a depression in the crust; or uplift, the raising of crustal materials. Earthquakes and volcanic eruptions also may result.

Orogenesis

There are two basic types of tectonism: epeirogenesis and orogenesis. The first takes its namefrom the Greek words epeiros, meaning "mainland," and genesis, or "origin." Epeirogenesis, which takes the form of either uplift or subsidence, is a chiefly vertical form of movement and plays little role in either plate tectonics or mountain building.

Orogenesis, on the other hand, is mountain building, as the prefix oros ("mountain") shows. Orogenesis involves the formation of mountain ranges by means of folding, faulting, and volcanic activity—lateral movements as opposed to vertical ones. Geologists typically use the term orogenesis, instead of just "mountain building," when discussing the formation of large belts of mountains from tectonic processes.

Plate Margins

Plates may converge (move toward one another), diverge (move away from one another), or experience transform motion, meaning that they slide against one another. Convergence usually is associated with subduction, in which one plate is forced down into the mantle and eventually undergoes partial melting. This typically occurs in the ocean, creating a depression known as an oceanic trench.

There are three types of plate margins, or boundaries between plates, depending on the two types of crusts that interact: oceanic with oceanic, continental with continental, or continental with oceanic. Any of these margins may be involved in mountain formation. Orogenic belts, or mountain belts, typically are situated in subduction zones at convergent plate boundaries and consist of two types.

The first type occurs when igneous material (i.e., rock from volcanoes) forms on the upper plate of a subduction zone, causing the surface to rise. This can take place either in the oceanic crust, in which case the mountains formed are called island arcs, or along continental-oceanic margins. The Aleutian Islands are an example of an island arc, while the Andes range represent mountains formed by the subduction of an oceanic plate under a continental one.

The second type of mountain belt occurs when continental plates converge or collide. When continental plates converge, one plate may "try" to subduct the other, but ultimately the buoyancy of the lower plate (which floats, as it were, on the lithosphere) pushes it upward. The result is the creation of a wide, unusually thick or "tall" belt. An example is the Himalayas, the world's tallest mountain range, which is still being pushed upward as the result of a collision between India and Asia that happened some 30 million years ago. (See Plate Tectonics for more about continental drift and collisions between plates.)

Real-Life Applications

What Is a Mountain?

In the 1995 film The Englishman Who Went Up a Hill But Came Down a Mountain, the British actor Hugh Grant plays an English cartographer, or mapmaker, sent in 1917 by his government to measure what is purportedly "the first mountain inside Wales." He quickly determines that according to standards approved by His Majesty, the "mountain" in question is, in fact, a hill. Much of the film's plot thereafter revolves around attempts on the part of the villagers to rescue their beloved mountain from denigration as a "hill," a fate they prevent by piling enough rocks and dirt onto the top to make it meet specifications.

This comedy aptly illustrates the somewhat arbitrary standards by which people define mountains. The British naturalist Roderick Peattie (1891-1955), in his 1936 book Mountain Geography, maintained that mountains are distinguished by their impressive appearance, their individuality, and their impact on the human imagination. This sort of qualitative definition, while it is certainly intriguing, is of little value to science; fortunately, however, more quantitative standards exist.

In Britain and the United States, a mountain typically is defined as a landform with an elevation of 985 ft. (300 m) above sea level. This was the standard applied in The Englishman, but the Welsh villagers would have had a hard time raising their "hill" to meet the standards used in continental Europe: 2,950 ft. (900 m) above sea level. This seems to be a more useful standard, because the British and American one would take in high plains and other nonmountainous regions of relatively great altitude. On the other hand, there are landforms in Scotland that rise only a few hundred meters above sea level, but their morphologic characteristics or shape seem to qualify them as mountains. Not only are their slopes steep, but the presence of glaciers and snow-capped peaks, with their attendant severe weather and rocky, inhospitable soil, also seem to indicate the topography associated with mountains.

Mountain Geomorphology

One area of the geologic sciences especially concerned with the study of mountains is geomorphology, devoted to the investigation of land-forms. Geomorphologists studying mountains must draw on a wide variety of disciplines, including geology, climatology, biology, hydrology, and even anthropology, because, as discussed at the conclusion of this essay, mountains have played a significant role in the shaping of human social groups.

From the standpoint of geology and plate tectonics, mountain geomorphology embraces a complex of characteristic formations, not all of which are necessarily present in a given orogen, or mountain. These include forelands and fore-deeps along the plains; foreland fold-and-thrust belts, which more or less correspond to "foothills" in layperson's terminology; and a crystalline core zone, composed of several types of rock, that is the mountain itself.

Environmental Zones

Mountain geomorphology classifies various environmental zones, from lowest to highest altitude. Near the bottom are flood plains, river terraces, and alluvial fans, all areas heavily affected by rivers flowing from higher elevations. (In fact, many of the world's greatest rivers flow from mountains, examples being the Himalayan Ganges and Indus rivers in Asia and the Andean Amazon in South America.) Farming villages may be found as high as the 9,845-ft. to 13,125-ft. range (3,000-4,000 m), an area known as a submontane, or forested region.

The tree line typically lies at an altitude of 14,765 ft. (4,500 m). Above this point, there is little human activity but plenty of geologic activity, including rock slides, glacial flow, and, at very high altitudes, avalanches. From the tree line upward, the altitude levels that mark a particular region are differentiated for the Arctic and tropical zones, with much lower altitudes in the Arctic mountains. For instance, the tree line lies at about 330 ft. (100 m) in the much colder Arctic zone.

Above the tree line is the subalpine, or montane, region. The mean slope angle of the mountain is less steep here than it is at lower or higher elevations: in the submontane, or forested region, below the tree line, the slope is about 30°, and above the subalpine, in the high alpine, the slope can become as sharp at 65°. In the subalpine, however, it is only about 20°, and because grass (if not trees) grows in this region, it is suited for grazing.

It may seem surprising to hear of shepherds bringing sheep to graze at altitudes of 16,400 ft. (5,000 m), as occurs in tropical zones. This does not necessarily mean that people live at such altitudes; more often than not, mountain dwellers have their settlements at lower elevations, and shepherds simply take their flocks up into the heights for grazing. Yet the ancient Bolivian city of Tiahuanaco, which flourished in about A.D. 600—some four centuries before the rise of the Inca—lay at an almost inconceivable altitude of 13,125 ft. (4,000 m), or about 2.5 times the elevation of Denver, Colorado, America's Mile-High City.

Classifying Mountains

There are several ways to classify mountains and groups of mountains. Mountain belts, as described earlier, typically are grouped according to formation process and types of plates: island arcs, continental arcs (formed with the subduction of an oceanic plate by a continental plate), and collisional mountain belts. Sometimes a mountain arises in isolation, an example being Kilimanjaro in Tanzania, Africa. Another example is Stone Mountain outside Atlanta, an exposed pluton, or a mass of crystalline igneous rock that forms deep in Earth's crust and rises. Many volcanoes, which we discuss later, arise individually, but mountains are most likely to appear in conjunction with other mountains. One such grouping, though far from the only one, is a mountain range, which can be defined as a relatively localized series of peaks and ridges.

Ranges, Chains, and Masses

Some of the world's most famous mountain ranges include the Himalayas, Karakoram Range, and Pamirs in central Asia; the Alps and Urals in Europe; the Atlas Mountains in Africa; the Andes in South America; and the Cascade Range, Sierra Nevada, Rocky Mountains, and Appalachians as well as their associated ranges in North America. Ranges affiliated with the Appalachians, for instance, include the Great Smokies in the south and the Adirondacks, Alleghenies, and Poconos in the north.

Several of the examples given here illustrate the fact that ranges are not the largest groupings of mountains. Sometimes series of ranges stretch across a continent for great distances in what are called mountain chains, an example of which is the Mediterranean chain of Balkans, Apennines, and Pyrenees that stretches across southern Europe.

There also may be irregular groupings of mountains, which lack the broad linear sweep of mountain ranges or chains and which are known as mountain masses. The mountains surrounding the Tibetan plateau represent an example of a mountain mass. Finally, ranges, chains, and masses of mountains may be combined to form vast mountain systems. An impressive example is the Alpine-Himalayan system, which unites parts of the Eurasian, Arabian, African, and Indo-Australian continental plates.

Other Types of Mountain

There are certain special types of orogeny, as when ocean crust subducts continental crust—something that is not supposed to happen but occasionally does. This rare variety of subduction is called obduction, and the mountains produced are called ophiolites. Examples include the uplands near Troodos in Cyprus and the Taconic Mountains in upstate New York.

Fault-block mountains appear when two continental masses push against each other and the upper portion of a continental plate splits from the deeper rocks. A portion of the upper crust, usually several miles thick, begins to move slowly across the continent. Ultimately it runs into another mass, creating a ramp. This can result in unusually singular mountains, such as Chief Mountain in Montana, which slid across open prairie on a thrust sheet.

Under the ocean is the longest mountain chain on Earth, the mid-ocean ridge system, which runs down the center of the Atlantic Ocean and continues through the Indian and Pacific oceans. Lava continuously erupts along this ridge, releasing geothermal energy and opening up new strips of ocean floor. This brings us to a special kind of mountain, typically resulting from the sort of dramatic plate tectonic processes that also produce earthquakes: volcanoes.

Volcanoes

Most volcanoes are mountains, and for this reason, it is appropriate to discuss them together; however, a volcano is not necessarily a mountain. A volcano may be defined as a natural opening in Earth's surface through which molten (liquid), solid, and gaseous material erupts. The word volcano also is used to describe the cone of erupted material that builds up around the opening or fissure. Because these cones are often quite impressive in height, they frequently are associated with mountains.

Though volcanic activity has been the case of death and destruction, it is essential to the planet's survival. Volcanic activity is the principal process through which chemical elements, minerals, and other compounds from Earth's interior reach its surface. These substances, such as carbon dioxide, have played a major role in the development of the planet's atmosphere, waters, and soils. Even today, soil in volcanic areas is among the richest on Earth. Volcanoes provide additional benefits in their release of geothermal energy, used for heating and other purposes in such countries as Iceland, Italy, Hungary, and New Zealand (see Energy and Earth). In addition, volcanic activity beneath the oceans promises to supply almost limitless geothermal energy, once the technology for its extraction becomes available.

Formation of Volcanoes

As noted earlier, land volcanoes are formed in coastal areas where continental and oceanic plates converge. As the oceanic plate is subducted and pushed farther and farther beneath the continental surface, the buildup of heat and pressure results in the melting of rock. This molten rock, or magma, tends to rise toward the surface and collect in magma reservoirs. Pressure buildup in the magma reservoir ultimately pushes the magma upward through cracks in Earth's crust, creating a volcano.

Volcanoes also form underwater, in which case they are called seamounts. Convergence of oceanic plates causes one plate to sink beneath the other, creating an oceanic trench; as a result, magma rises from the subducted plate to fashion volcanoes. If the plates diverge, magma seeps upward at the ridge or margin between plates, producing more seafloor. This process, known as seafloor spreading, leads to the creation of volcanoes on either side of the ridge.

In some places a plate slides over a stationary area of volcanic activity, known as a hot spot. These are extremely hot plumes of magma that well up from the crust, though not on the edge or margin of a plate. A tectonic plate simply drifts across the hot spot, and as it does, the area just above the hot spot experiences volcanic activity. Hot spots exist in Hawaii, Iceland, Samoa, Bermuda, and America's Yellowstone National Park.

Classifying Volcanoes

Volcanoes can be classified in terms of their volcanic activity, in which case they are labeled as active (currently erupting), dormant (not currently erupting but likely to do so in the future), or extinct. In the case of an extinct volcano, no eruption has been noted in recorded history, and it is likely that the volcano has ceased to erupt permanently.

In terms of shape, volcanoes fall into four categories: cinder cones, composite cones, shield volcanoes, and lava domes. These types are distinguished not only by morphologic characteristics but also by typical sizes and even angles of slope. For instance, cinder cones, built of lava fragments, have slopes of 30° to 40°, and are seldom more than 1,640 ft. (500 m) in height.

Composite cones, or stratovolcanoes, are made up of alternating layers of lava (cooled magma), ash, and rock. (The prefix strato refers to these layers.) They may slope as little as 5° at the base and as much as 30° at the summit. Stratovolcanoes may grow to be as tall as 2-3 mi. (3.2-4.8 km) before collapsing and are characterized by a sharp, dramatic shape. Examples include Fuji, a revered mountain that often serves as a symbol of Japan, and Washington state's Mount Saint Helens.

A shield volcano, which may be a solitary formation and often is located over a hot spot, is built from lava flows that pile one on top of another. With a slope as little as 2° at the base and no more than 10° at the summit, shield volcanoes are much wider than stratovolcanoes, but sometimes they can be impressively tall. Such is the case with Mauna Loa in Hawaii, which at 13,680 ft. (4,170 m) above sea level is the world's largest active volcano. Likewise, Mount Kilimanjaro, though long ago gone dormant, is the tallest mountain in Africa.

Finally, there are lava domes, which are made of solid lava that has been pushed upward. Closely related is a volcanic neck, which often forms from a cinder cone. In the case of a volcanic neck, lava rises and erupts, leaving a mountain that looks like a giant gravel heap. Once it has become extinct, the lava inside the volcano begins to solidify. Over time the rock on the exterior wears away, leaving only a vent filled with solidified lava, usually in a funnel shape. A dramatic example of this appears at Shiprock, New Mexico.

Volcanic Eruptions

Volcanoes frequently are classified by the different ways in which they erupt. These types of eruption, in turn, result from differences in the material being disgorged from the volcano. When the magma is low in gas and silica (silicon dioxide, found in sand and rocks), the volcano erupts in a relatively gentle way. Its lava is thin and spreads quickly. Gas and silica-rich magma, on the other hand, brings about a violent explosion that yields tarlike magma.

There are four basic forms or phases of volcanic eruption: Hawaiian, Strombolian, Vulcanian, and Peleean. The Hawaiian phase is simply a fountain-like gush of runny lava, without any explosions. The Strombolian phase (named after a volcano on a small island off the Italian peninsula) involves thick lava and mild explosions. In a Vulcanian phase, magma has blocked the volcanic vent, and only after an explosion is the magma released, with the result that tons of solid material and gases are hurled into the sky. Most violent of all is the Peleean, named after Mount Pelée on Martinique in the Caribbean (discussed later). In the Peleean phase, the volcano disgorges thick lava, clouds of gas, and fine ash, all at formidable velocities.

Accompanying a volcanic eruption in many cases are fierce rains, the result of the expulsion of steam from the volcano, after which the steam condenses in the atmosphere to form clouds. Gases thrown into the atmosphere are often volatile and may include hydrogen sulfide, fluorine, carbon dioxide, and radon. All are detrimental to human beings when present in sufficient quantity, and radon is radioactive.

Not surprisingly, the eruption of a volcano completely changes the morphologic characteristics of the landform. During the eruption a crater is formed, and out of this flows magma and ash, which cool to form the cone. In some cases, the magma chamber collapses just after the eruption, forming a caldera, or a large, bowl-shaped crater. These caldera (the plural as well as singular form) may fill with water, as was the case at Oregon's Crater Lake.

Infamous Volcanic Disasters

Volcanoes result from some of the same tectonic forces as earthquakes (see Seismology), and, not surprisingly, they often have resulted in enormous death and destruction. Some remarkable examples include:

  • Vesuvius, Italy, A.D. 79 and 1631: Situated along the Bay of Naples in southern Italy, Vesuvius has erupted more than 50 times during the past two millennia. Its most famous eruption occurred in A.D. 79, when the Roman Empire was near the height of its power. The first-century eruption buried the nearby towns of Pompeii and Herculaneum, where bodies and buildings were preserved virtually intact until excavation of the area in 1748. Another eruption, in 1631, killed some 4,000 people.
  • Krakatau, Indonesia, A.D. 535 (?) and 1883: The most famous eruption of Krakatau occurred in 1883, resulting in the loss of some 36,000 lives. The explosion, which was heard 3,000 mi. away, threw 70-lb. (32-kg) boulders as far as 50 mi. (80 km). It also produced a tsunami, or tidal wave, 130 ft. (40 m) high, which swept away whole villages. In addition, the blast hurled so much dust into the atmosphere that the Moon appeared blue or green for two years. It is also possible that Krakatau erupted in about A.D. 535, causing such a change in the atmosphere that wide areas of the world experienced years without summer. (See Earth Systems for more on this subject.)
  • Tambora, Indonesia, 1815: Another Indonesian volcano, Tambora, killed 12,000 people when it erupted in 1815. As with Krakatau in 535, this eruption was responsible for a year without summer in 1816 (see Earth Systems).
  • Pelée, Martinique, 1902: When Mount Pelée erupted on the Caribbean island of Martinique, it sent tons of poisonous gas and hot ash spilling over the town of Saint-Pierre, killing all but four of its 29,937 residents.
  • Saint Helens, Washington, 1980: Relatively small compared with earlier volcanoes, the Mount Saint Helens blast is still significant because it was so recent and took place in the United States. The eruption sent debris flying upward 1,300 ft. (396 m) and caused darkness over towns as far as 85 mi. (137 km) away. Fifty-seven people died in the eruption and its aftermath.
  • Pinatubo, Philippines, 1991: Dormant for 600 years, Mount Pinatubo began to rumble one day in 1991 and, after a few days, erupted in a cloud that spread ash 6 ft. (1.83 m) deep along a radius of 2 mi. (3.2 km). A U.S. air base 15 mi. (24 km) away was buried. The blast threw 20 million tons (18,144,000 metric tons) of sulfuric acid 12 mi. (19 km) into the stratosphere, and the cloud ultimately covered the entire planet, resulting in moderate cooling for a few weeks.

The Impact of Mountains

Volcanic eruptions are among the most dramatic effects produced by mountains, but they are far from the only ones. Every bit as fascinating are the effects mountains produce on the weather, on the evolution of species, and on human society. In each case, mountains serve as a barrier or separator—between masses of air, clouds, and populations.

Wind pushes air and moisture-filled clouds up mountain slopes, and as the altitude increases, the pressure decreases. As a result, masses of warm, moist air become larger, cooler, and less dense. This phenomenon is known as adiabatic expansion, and it is the same thing that happens when an aerosol can is shaken, reducing the pressure of gases inside and cooling the surface of the can. Under the relatively high-pressure and high-temperature conditions of the flatlands, water exists as a gas, but in the heights of the mountaintops, it cools and condenses, forming clouds.

Rain Shadows

As the clouds rise along the side of the mountain, they begin to release heavy droplets in the form of rain and, at higher altitudes, snow. By the time the cloud crosses the top of the mountain, however, it will have released most of its moisture, and hence the other side of the mountain may be arid. The leeward side, or the side opposite the wind, becomes what is called a rain shadow.

Although they are only 282 mi. (454 km) apart, the cities of Seattle and Spokane, Washington, have radically different weather patterns. Famous for its almost constant rain, Seattle lies on the windward, or wind-facing, side of the Cascade Range, toward the Pacific Ocean. On the leeward side of the Cascades is Spokane, where the weather is typically warm and dry. Though it is only on the other side of the state, Spokane might as well be on the other side of the continent. Indeed, it is associated more closely with the arid expanses of Idaho, whereas Seattle belongs to a stretch of cold, wet Pacific terrain that includes San Francisco and Portland, Oregon.

Much of the western United States consists of deserts formed by rain shadows or, in some cases, double rain shadows. Much of New Mexico, for instance, lies in a double rain shadow created by the Rockies in the west and Mexico's Sierra Madres to the south. In southern California, tall redwoods line the lush windward side of the Sierra Nevadas, while Death Valley and the rest of the Mojave Desert lies in the rain shadow on the eastern side. The Great Basin that covers eastern Oregon, southern Idaho, much of Utah, and almost all of Nevada, likewise is created by the rain shadow of the Sierra Nevada-Cascade chain.

Mountains and Species

One of the most intriguing subjects involved in the study of mountains is their effects on large groups of plants, animals, and humans. Mountains may separate entire species, creating pockets of flora and fauna virtually unknown to the rest of the world. Thus, during the 1990s, huge numbers of species that had never been catalogued were discovered in the mountains of southeast Asia.

The formation of mountains and other landforms may even lead to speciation, a phenomenon in which members of a species become incapable of reproducing with other members, thus creating a new species. When the Colorado River cut open the Grand Canyon, it separated groups of squirrels that lived in the high-altitude pine forest. Over time these populations ceased to interbreed, and today the Kaibab squirrel of the north rim and the Abert squirrel of the south are separate species, no more capable of interbreeding than humans and apes.

Human Societies and Mountains

Although the Appalachians of the eastern United States are hundreds of millions of years old, most ranges are much younger. Most will erode or otherwise cease to exist in a relatively short time (short, that is, by geologic standards), yet to humans throughout the ages, mountains have seemed a symbol of permanence. This is just one aspect of mountains' impact on the human psyche.

In his 1975 study of symbolism in political movements, Utopia and Revolution, Melvin J. Lasky devoted considerable space to the mountain and its association with divinity through figures such as the Greek Olympians and Noah and Moses in the Bible. Clearly, mountains have proved enormously influential on human attitudes, and nowhere is this more obvious than in relation to the people who live in the mountains. Whether the person is a coal miner from Appalachia or a rancher from the Rockies, a Scottish highlander or a Quechua-speaking Peruvian, the mentality is similar, characterized by a combination of hardiness, fierce independence, and disdain for lowland ways.

These characteristics, combined with the harsh weather of the mountains, have made mountain warfare a challenge to lowland invaders. This explains the fact that Switzerland has kept itself free from involvement in European wars since Napoleon's time, and why the independent Scottish Highlands were long a thorn in England's side. It also explains why neither the British nor the Russian empires could manage to control Afghanistan fully during their struggle over that mountainous nation in the late nineteenth and early twentieth centuries.

Britain eventually pulled out of the "Great Game," as this struggle was called, but Russia never really did. Many years later, the Soviets became bogged down in a war in Afghanistan that they could not win. The war, which lasted from 1979 to 1989, helped bring about the end of the Soviet Union and its system of satellite dictatorships. More than a decade later, as the United States launched strikes against Afghanistan in 2001, a superpower once again faced the challenge posed by one of the poorest, most inhospitable nations on Earth.

But the independence of the mountaineer is deceptive; in fact, mountains have little to offer, economically, other than their beauty and the resources deep beneath their surfaces. In other words, they are really of value only to flatland tourists and mining companies. Since few mountain environments offer much promise agriculturally, the people of the mountains are dependent on the flatlands for sustenance. Gorgeous and rugged as they are, such mountainous states as Colorado or Wyoming might be as poor as Afghanistan were it not for the fact that they belong to a larger political unit, the United States.

Where to Learn More

A Geological History of Rib Mountain, Wisconsin (Web site). <http://www.uwmc.uwc.edu/geography/ribmtn/ribmtn.htm>.

Gore, Pamela. "Physical Geology at Georgia Perimeter College" (Web site). <http://www.gpc.peachnet.edu/~pgore/geology/geo101.htm>.

Kraulis, J. A., and John Gault. The Rocky Mountains: Crest of a Continent. New York: Facts on File, 1987.

Michigan Technological University Volcanoes Page (Web site). <http://www.geo.mtu.edu/volcanoes/>.

Oregon Geology—Cascade Mountains (Web site). <http://sarvis.dogami.state.or.us/learnmore/Cascades.HTM>.

Prager, Ellen J., Kate Hutton, Costas Synolakis, et al. Furious Earth: The Science and Nature of Earthquakes, Volcanoes, and Tsunamis. New York: McGraw-Hill, 2000.

Schaer, Jean-Paul, and John Rodgers. The Anatomy of Mountain Ranges. Princeton, NJ: Princeton University Press, 1987.

Sigurdsson, Haraldur. Encyclopedia of Volcanoes. San Diego: Academic Press, 2000.

Silver, Donald M., and Patricia Wynne. Earth: The Ever-Changing Planet. New York: Random House, 1989.

Volcanoes, Glaciers, and Plate Tectonics: The Geology of the Mono Basin (Web site). <http://www.r5.fs.fed.us/inyo/vvc/mono/vg&26pt.htm>.


A feature of the Earth's surface that rises high above its base and has generally steep slopes and a relatively small summit area. Commonly the features designated as mountains have local heights measurable in thousands of feet, lesser features of the same type being called hills, but there are many exceptions. See also Hill and mountain terrain.

Mountains rarely occur as isolated individuals. Instead they are usually found in roughly circular groups or massifs, such as the Olympic Mountains of northwestern Washington, or in elongated ranges, like the Sierra Nevada of California. An array of linked ranges and groups, such as the Rocky Mountains, the Alps, or the Himalayas, is a mountain system. North America, South America, and Eurasia possess extensive cordilleran belts, within which the bulk of their higher mountains occur. See also Cordilleran belt; Massif; Mountain systems.

As a rule, mountains represent portions of the Earth's crust that have been raised above their surroundings by upwarping, folding, or buckling, and have been deeply carved by streams or glaciers into their present surface form. Some individual peaks and massifs have been constructed upon the surface by outpourings of lava or eruptions of volcanic ash. See also Orogeny.


Top

noun

  1. A group of things gathered haphazardly: agglomeration, bank1, cumulus, drift, heap, hill, mass, mess, mound, pile, shock2, stack, tumble. See order/disorder.
  2. A great deal: abundance, mass, much, plenty, profusion, wealth, world. Informal barrel, heap, lot, pack, peck2, pile. Regional power, sight. See big/small/amount.


n

Definition: very large hill
Antonyms: crevasse, valley

Top
mountain, high land mass projecting conspicuously above its surroundings and usually of limited width at its summit. Although isolated mountains are not unusual, mountains commonly form ranges, comprising either a single complex ridge or a series of related ridges. A group of ranges closely related in form, origin, and alignment is a mountain system; an elongated group of systems is a chain; and a complex of ranges, systems, and chains continental in extent is called a cordillera, zone, or belt.

Global Distribution and Impact on Humanity

Most of the great mountain systems now in existence were developed fairly late in geologic history. The greatest mountain masses are in North and South America, including the Andes, Rockies, Sierra Nevada, and Coast Ranges of the United States, Canada, and Alaska; and the Eurasian mountain belt, in which lie the Pyrenees, Atlas, Alps, Balkans, Caucasus, Hindu Kush, Himalayas, and other ranges. Among notable single peaks are Everest, K2 (Godwin-Austen), and Kanchenjunga in Asia; Aconcagua, Chimborazo, and Cotopaxi in South America; McKinley, Logan, and Popocatepetl in North America; Mont Blanc and Elbrus in Europe; Kilimanjaro, Kenya, and Ruwenzori in Africa.

Mountains have important effects upon the climate, population, economy, and state of civilization of the regions in which they occur. By intercepting prevailing winds they cause precipitation; regions on the windward side of a great range thus have plentiful rainfall, while those on its lee side are arid. Mountains are in general thinly populated, not only because the cold climate and rarefied atmosphere of high regions are unfavorable to human life, but also because the higher reaches of mountains are unfit for agriculture. Mountains frequently contain valuable mineral ores, deposited out of solution by water or by gases. Mountains act as natural barriers between countries and peoples; they determine the routes followed by traders, migrants, and invading armies. The difficulties of travel and communication in mountain regions tend to favor political disunity.

The Origins of Mountains

Mountains and mountain ranges have varied origins. Some are the erosional remnants of plateaus; others are cones built up by volcanoes, such as Mt. Rainier in Washington, or domes pushed up by intrusive igneous rock (see rock), such as the Black Hills of South Dakota and the Henry Mts., Utah. Fault-block mountains (see fault) are formed by the raising of huge blocks of the earth's surface relative to the neighboring blocks. The Basin and Range region of Nevada, Arizona, New Mexico, and Utah is one of the most extensive regions of fault-block mountains.

All the great mountain chains of the earth are either fold mountains or complex structures in whose formation folding, faulting, or igneous activity have taken part. The growth of folded or complex mountain ranges is preceded by the accumulation of vast thicknesses of marine sediments. It was first suggested in the late 1800s that these sediments accumulated in elongated troughs, or geosynclines, that were occupied by arms of the sea. While some of the sediment was derived from the interior of the continent, great quantities of sediment were apparently derived from regions now offshore from the continent. For examples, sedimentary rocks of the Appalachian Mts. formed in a vast geosyncline that extended from the Gulf states northeastward through the eastern states and New England, and into E Canada. It is now recognized that great thicknesses of sediment can occur wherever there is subsidence (lowering of the earth's crust).

The best modern analogues of geosynclines appear to be the thick deposits of sediment making up the continental shelves and continental rises (see ocean). Most geologists now believe that the geosynclinal sediments found in mountain ranges were initially deposited under similar conditions. The period of sedimentation is followed by folding and thrust faulting, with most high mountain ranges uplifted vertically subsequent to folding. The movements of the earth's surface that result in the building of mountains are compression, which produces folding, thrust faulting, and possibly some normal faulting; tension, which produces most normal faulting; and vertical uplift. Mountains are subject to continuous erosion during and after uplift. Sharp peaks are formed and are subsequently attacked and leveled. Mountains may be entirely base-leveled, or they may be rejuvenated by new uplifts.

The ultimate cause of mountain-building forces has been a source of controversy, and many hypotheses have been suggested. An old hypothesis held that earth movements were adjustments of the crust of the earth to a shrinking interior that contracted and set up stresses due either to heat loss or gravitational compaction. Another hypothesis suggested that earth movements were primarily isostatic, i.e., adjustments that kept the weights of sections of the crust nearly equal (see continent). A third hypothesis, popular from the early 1960s to today, ascribed mountain-building stresses to convection currents in a hot semiplastic region in the earth's mantle.

According to the plate tectonics theory, the lithosphere is broken into several plates, each consisting of oceanic crust, continental crust, or a combination of both. These plates are in constant motion, sideswiping one another or colliding, and continually changing in size and shape. Where two plates collide, compressional stresses are generated along the margin of the plate containing a continent. Such stresses result in the deformation and uplift of the continental shelf and continental rise sediments into complex folded and faulted mountain chains (see seafloor spreading; continental drift).

Bibliography

See W. M. Bueler, Mountains of the World (1970); K. Hsu, Mountain Building Processes (1986); A. J. Gerrard, Mountain Environments (1990).


Top

A natural elevation of a planetary surface.


Word Tutor:

mountain

Top
pronunciation

IN BRIEF: An elevation higher than a hill.

pronunciation If you found a man at the top of the mountain, he did not fall there. — Unknown, from Albert W. Daw Collection.

LearnThatWord.com is a free vocabulary and spelling program where you only pay for results!

Top
sign description: One fist hits on the back of the other, followed by both open flat hands moving upwards.




Quotes About:

Mountains

Top

Quotes:

"The ordinary man looking at a mountain is like an illiterate person confronted with a Greek manuscript." - Aleister Crowley

"I can't do with mountains at close quarters -- they are always in the way, and they are so stupid, never moving and never doing anything but obtrude themselves." - D. H. Lawrence

"Mountains are to the rest of the body of the earth, what violent muscular action is to the body of man. The muscles and tendons of its anatomy are, in the mountain, brought out with force and convulsive energy, full of expression, passion, and strength." - John Ruskin

"Thou hast a voice, great Mountain, to repeal. Large codes of fraud and woe; not understood by all, but which the wise, and great, and good interpret, or make felt, or deeply feel." - Percy Bysshe Shelley

Climbing the mountain and reaching the top denotes achieving one's goals. Descending the mountain is returning after a success or letting go of insurmountable issues. Looking at the mountain may denote evaluating a major decision.



Rock band

When it comes to heavy rock bands, Mountain definitely qualifies. The group was in the vanguard of hard rock/pre-heavy metal bands from the late 1960s, and Leslie West’s thunderous riffing on guitar was a cornerstone of rock’s original wall of sound. West was the size of a National Football League lineman, and the band no doubt took its moniker as a monument to his impressive stature. Numerous musicians have played under the Mountain banner over the years, but the group at its most essential consists of just three members: West, bassist Felix Pappalardi, and drummer Corky Laing.

West was born Leslie Weinstein on October 22, 1945, in Forest Hills, New York. He is one of many second generation rock ’n rollers whose life was changed by seeing Elvis Presley for the first time. West’s uncle was a writer for the Jackie Gleason Show and took him to see a performance of its summer replacement show hosted by Tommy and Jimmy Dorsey. Presley was a guest on the show and West was transfixed. "I’ve been playing guitar ever since that day," he told Goldmine magazine in 1995. West attended numerous private schools, but a standardized education was not for him. "In school they just weren’t teaching me anything I was interested in, and the teachers were asking me questions I already knew the answers to, and learning dates and all that stuff, it just never appealed to me," he told Goldmine. Instead, he worked as a jeweler for a short time, but mainly spent his time practicing guitar. West’s first band was called the Vagrants, a barely capable Long Island group that specialized in rhythm and blues, and actually recorded the song "Respect" before Aretha Franklin’s famous version. The Vagrants recorded several singles for the Vanguard label, and then for Atco. They were assigned to work with producer Felix Pappalardi, who was then riding high as the producer of famed English power trio Cream.

Pappalardi was born in 1939 in the Bronx, New York, and began learning guitar at the age of four. Determined to devote his life to making music, he attended the High School of Music and Art in Manhattan. After stints in college and the United States Army, he returned to New York and fell headlong into the burgeoning Greenwich Village folk scene. Among the musicians he worked with were John Sebastian (soon to be of the Lovin’ Spoonful), Cass Elliot (future member of the Mamas and the Papas), Richie Havens, and Joan Baez. His early successes as a producer include the Youngbloods’ seminal single "Get Together." His reputation skyrocketed after his work with Cream, whose records Disraeli Gears, Wheels of Fire, and Goodbye he produced and arranged.

West talked about meeting Pappalardi with Goldmine: "Atlantic Records sent him down to produce for the Vagrants. He walked in and I think he had just met Cream. He produced our single, we broke up and then he said, ‘Well, if you guys get something together, give

me a call.’ Later he began working with Cream, and he said if I’d got something together, he would give it a listen, so I called him right away, as soon as he got back from England. He liked it. But then he went in the studio with me and he didn’t like my drummer. So I had to get another drummer; I had a bass player and an organ player. Felix didn’t like the bass player, so his partner suggested he play bass, so he did. That was the beginning of my solo career."

What is often thought of as the first Mountain album is really a Leslie West solo album, which was not incidentally titled Mountain. Pappalardi plays bass on the record, N.D. Smart played drums, and in an attempt to differentiate the sound from that of Cream, Steve Knight was added on keyboards. The lineup from the West album became a band, and they debuted at San Francisco’s Fillmore West in July of 1969. They played a couple of other gigs, and then, by virtue of sharing management with Jimi Hendrix, their fifth show ever was played at Woodstock. "I remember hanging around backstage and Janis Joplin had this gorgeous girlfriend she was hanging out with," West told Goldmine about the famed concert. "I was in awe of everything there. I remember Creedence Clearwater Revival went on and they did one hit after another. I couldn’t believe how many hit singles they had! Our first album I think was just coming out."

Drummer Smart had a falling out with the band after that, and they immediately replaced him with Corky Laing, who had been hanging out with the group, and whose own band had a record produced by Pappalardi’s wife, Gail Collins. Laing was born on January 26, 1948, in Montreal, Canada. With its lineup solidified for a while, they recorded Mountain Climbing, technically the group’s debut, which went gold thanks in large part to the hit single and enduring Mountain classic "Mississippi Queen." The group struck gold again with the album Nantucket Sleighride, which featured a jam-heavy title track. After that album, the group quickly recorded another, the ominously titled Flowers of Evil, and a live disc, The Road Goes Ever On. But by then, drugs and dissension in the ranks had made being in the band unbearable, and the group split up.

Papplardi returned to production work. Knight all but vanished. West and Laing joined with ex-Cream bassist Jack Bruce to form the second-tier supergroup West, Bruce and Laing, which recorded three albums before disbanding. From there, West and Laing soldiered on in a group called Leslie West’s Wild West Show. Pappalardi—who suffered hearing damage from his days as a musician, particularly with Mountain, who always played at top volume—rejoined in 1974. They recorded the album Avalanche, and then broke up again. After that, West resumed his solo career, though Laing continued to work with him. Albums from this period include The Great Fatsby— West was always one to make a joke about his weight at his own expense—with the Leslie West Band. A long fallow period came in the late 70s and early ’80s, during which time West did not record. The inner circle of Mountain was sundered forever in 1983 when Pappalardi’s wife shot and killed him.

West returned in 1985 with a new version of the band that included Laing and bassist Mike Clarke. They recorded the album Go for Your Life in 1986. West’s solo albums Theme and Alligator arrived in the late ’80s. Laing meanwhile led a blues band that featured former Rolling Stones guitarist Mick Taylor.

The ’90s were a return to even more action for West and Laing separately, and in tandem. West has continued to make solo albums, and has even shed some of his famous poundage. He remains in the limelight these days as a musician, but also as a frequent guest on Howard Stern’s syndicated radio show. Laing recently formed the band Cork, featuring former Spin Doctors guitarist Eric Schenkman. Their album Speed ofThoughtwas released in 1999. For years, Laing was also an executive for the Canadian branch of Polygram Records. Mountain continues to tour occasionally, and lineups in the mid-’90s occasionally featured former Jimi Hendrix Experience bassist Noel Redding. "Needless to say, Mountain without Felix is not the original Mountain," Laing told Goldmine. "It’s the other two guys, it’s two-thirds, and we don’t try to fool anybody by that."

Selected discography
Mountain Climbing, Windfall, 1970.
Nantucket Sleighride, Windfall, 1971.
Flowers of Evil, Windfall, 1971.
Mountain Live (The Road Goes Ever On), Windfall, 1972.
Best of Mountain, Windfall, 1973.
Twin Peaks, Columbia, 1973.
Avalanche, Columbia, 1974.
Go for Your Life, Scotti Bros., 1986.
Over the Top, Columbia Legacy, 1995.

Leslie West
Mountain, Windfall, 1969.
The Great Fatsby, Phantom, 1975.
Live, Blues Bureau International, 1993.
Dodgin’the Dirt, Blues Bureau International, 1994.
Blood of the Sun, Raven, 1996.
As Phat as It Gets, Lightyear, 1999.

West, Bruce & Laing
Why Dontcha, Columbia, 1972.
Whatever Turns You On, Columbia, 1973.
Live ‘n’ Kickin’, Columbia.

Corky Laing
(With Cork) Speed of Thought, Lightyear, 1999

Sources
Books
Graff, Gary, and Daniel Durchholz, editors, MusicHound Rock: The Essential Album Guide, Visible Ink Press, 1999.
Romanowski, Patricia, and Holly George-Warren, editors, The Rolling Stone Encyclopedia of Rock and Roll, Fireside/Simon & Schuster, 1995.

Periodicals
Goldmine, 1995.

Online
Leslie West website, http://www.lesliewest.cjb.net (September 2000).

Related in some way to high altitude.

Random House Word Menu:

categories related to 'mountain'

Top
Random House Word Menu by Stephen Glazier
For a list of words related to mountain, see:

Chimborazo, Ecuador, the point farthest from the center of the Earth.
The view of Jeff Davis Peak from the glacier-carved summit of Wheeler Peak, Nevada. Because Boundary Peak, Nevada is partially in California, and is actually a sub-peak of Montgomery Peak, the shorter Wheeler Peak can be considered the tallest mountain in Nevada.
Mountain in Carbon County, Utah
Chomo Lonzo Makalu Mount Everest Tibetan Plateau Rong River Changtse Rongbuk Glacier North Face East Rongbuk Glacier North Col north ridge route Lhotse Nuptse South Col route Gyachung Kang Cho Oyu Press hyperlinks (or button to enlarge image)
The Himalayan mountain range with Mount Everest


A mountain is a large landform that stretches above the surrounding land in a limited area usually in the form of a peak. A mountain is generally steeper than a hill. The adjective montane is used to describe mountainous areas and things associated with them. The study of mountains is called orography. Exogeology deals with planetary mountains, which in that branch of science are usually called montes (singular—mons). The highest mountain on Earth based from sea level is Mount Everest (8,848 m (29,029 ft)) in the Himalayas of Asia. The highest known mountain in the Solar System is Olympus Mons on the planet Mars at 21,171 m (69,459 ft). Mountains and mountain ranges on Earth are typically formed by the movement and/or interaction of lithospheric plates.

Contents

Definition

The biblical Mount Ararat, showing the Khor Virap monastery

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.[1] 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."[1]

Whether a landform is called a mountain may depend on usage among the local people. The highest point in San Francisco, California, is called Mount Davidson, notwithstanding its height of 300 m (980 ft), which makes it ten feet short of the minimum for a mountain by American designations.[citation needed] Similarly, Mount Scott outside Lawton, Oklahoma is only 251 m (823 ft) from its base to its highest point.

Definitions of "mountain" include:[2]

  • Height over base of at least 2,500 m (8,202 ft);
  • Height over base of 1,500 m (4,921 ft).–2,500 m (8,202 ft). with a slope greater than 2 degrees
  • Height over base of 1,000 m (3,281 ft).–1,500 m (4,921 ft). with a slope greater than 5 degrees
  • Local (radius 7,000 m (22,966 ft). elevation greater than 300 m (984 ft)., or 300 m (984 ft)–1,000 m (3,281 ft). if local (radius 7,000 m (22,966 ft). elevation is greater than 300 m (984 ft).

By this definition,[which?] mountains cover 64% of Asia, 25% of Europe, 22% of South America, 17% of Australia, and 3% of Africa. As a whole, 24% of the Earth's land mass is mountainous and 10% of people live in mountainous regions.[3] Most of the world's rivers are fed from mountain sources, and more than half of humanity depends on mountains for water.[4][5]

Characteristics

Tall mountains reach into the colder layers of the atmosphere. They are consequently subject to glaciation, and erosion through frost action. Such processes produce the peak shape. Some mountains have glacial lakes, created by melting glaciers; for example, there are an estimated 3,000 glacial lakes in Bhutan. Mountains can be eroded and weathered, altering their characteristics over time.

Tall mountains have different climatic conditions at the top than at the base, and will thus have altitudinal zonation of ecosystems. At the highest elevations, trees cannot grow, and whatever life may be present will be of the alpine type, resembling tundra.[6] Just below the tree line, one may find subalpine forests of needleleaf trees, which can withstand cold, dry conditions.[7] In regions with dry climates, the tendency of mountains to have higher precipitation as well as lower temperatures also provides for varying conditions, which in turn leads to differing flora and fauna.[6][8] Some plants and animals found in these zones tend to become isolated since the conditions above and below a particular zone will be inhospitable and thus constrain their movements or dispersal. On the other hand, birds, being capable of flight, may take advantage of montane habitats and migrate into a region that would otherwise not provide appropriate habitat.[9] These isolated ecological systems, or microclimates, are known as sky islands.[10]

Mountains are generally colder than their surrounding lowlands due to the way that the sun heats the surface of the Earth. Practically all the heat at the surface of the Earth comes from the sun, in the form of solar energy. The sun's radiation is absorbed by land and sea, whence the heat is transferred into the air. Static air is a poor conductor of heat, so conduction of heat from the ground to the atmosphere is negligible. Heat is mainly transferred into the atmosphere through convection and radiation. The air immediately adjacent to the warmed surface will rise due to its buoyancy, leading to convective circulation, in the form of thermals, within the lowest layer of the atmosphere, the troposphere. When heat radiates from the surface of the earth, it is released as long-wave radiation, which can move freely through gases composed of diatomic molecules (such as the atmosphere's oxygen and nitrogen), but is readily absorbed by triatomic molecules, such as carbon dioxide and water vapor. Since most of the atmosphere's quantity of such triatomic gases is contained within the troposphere, this portion of the atmosphere is readily heated by the earth's radiation. The tropopause forms a blanket of air keeping the surface warm. This is the Greenhouse Effect. The higher the altitude, the less of this blanket there is to keep in the heat. Thus, higher elevations, such as mountains, are colder than surrounding lowlands.[11] Air temperature in the lowest layer of the atmosphere, the troposphere, decreases with gains in altitude. The rate at which the temperature drops with elevation, called the environmental lapse rate, is not constant (it can fluctuate throughout the day or seasonally and also regionally), but a normal lapse rate is 5.5°C per 1,000 m (3.57°F per 1,000 ft).[12][13][14] The temperature continues to drop with increasing altitude, until the tropopause (11,000m or 36,089 ft in the U.S. Standard Atmosphere, where it does not decrease further. However, this is higher than the highest mountaintop.

Mountains are generally less preferable for human habitation than lowlands; the weather is often harsher, and there is little level ground suitable for agriculture. The decreasing atmospheric pressure means that less oxygen is available for breathing, and there is less protection against solar radiation (UV). Acute mountain sickness (caused by hypoxia—a lack of oxygen in the blood) affects over half of lowlanders who spend more than a few hours above 3,500 metres (11,480 ft).

Many mountains and mountain ranges throughout the world have been left in their natural state, and are today primarily used for recreation, while others are used for logging, mining, grazing, or see little use. Some mountains offer spectacular views from their summits, while others are densely wooded. Summit accessibility is affected by height, steepness, latitude, terrain, weather. Roads, ski lifts, or aerial tramways allow access. Hiking, backpacking, mountaineering, rock climbing, ice climbing, downhill skiing, and snowboarding are recreational activities enjoyed on mountains. Mountains that support heavy recreational use (especially downhill skiing) are often the locations of mountain resorts.

Mountains are made up of earth and rock materials. The outermost layer of the Earth or the Earth's crust is composed of seven primary plates. When two plates move or collide each other, vast land areas are uplifted, forming mountains.

Types

Classified by the geological processes that shape them, there are five major types of mountains:

Left to right: Mount Everest, Lhotse and Ama Dablam in the Himalayas
Mount Kinabalu, 4,101 metres (13,455 ft), Malaysia
The Adirondack Mountains of New York are remnants of an eroded plateau.
Fold mountains
Fold mountains are the most common type of mountains. They are formed due to collision of two plates, causing folding of the Earth's crust. Examples of fold mountains are the Himalayas of Asia and the Alps in Europe.[citation needed]
Fault-Block mountains
As the name suggests, fault-block mountains or fault mountains are formed when blocks of rock materials slide along faults in the Earth's crust. There are two types of block mountains, namely the lifted and tilted. Lifted mountains have two steep sides; whereas, the tilted type has one steep side and a gentle sloping side. Examples of fault-block mountains are found in the Sierra Nevada mountain range of the western United States.
Volcanic mountains
Volcanic mountains are formed due to volcanic eruptions where magma piles up on the surface of the Earth. Examples of volcanoes include Mount Fuji in Japan and Mount Pinatubo in the Philippines. Inactive or extinct volcanic mountain include Mount Elbrus in Russia, Mount Kinabalu in Malaysia, Cotopaxi in Ecuador and Aconcagua in Argentina/
Dome mountains
Dome mountains are formed when the hot magma rises from the mantle and uplifts the overlying sedimentary layer of the Earth's crust. In the process, the magma is not erupted, but it cools down and forms the core of the mountain. They are called dome mountains due to their appearance that resembles a dome shape. An example of a dome mountain is Navajo Mountain in the U.S. state of Utah.
Plateau mountains
Plateau mountains are formed erosion of an uplifted plateau. Examples of plateau mountains are in the Adirondack Mountains in the U.S. state of New York.

Geology

A mountain is usually produced by the movement of lithospheric plates, either orogenic movement or epeirogenic movement. 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. The absolute heights of features termed mountains and hills vary greatly according to an area's terrain. The major mountains tend to occur in long linear arcs, indicating tectonic plate boundaries and activity. Two types of mountain are formed in this way depending on how the rock reacts to the tectonic forces, — fold mountains or fault-block mountains. Other mountain building processes include volcanoes and sea floor spreading.

Fold mountains

Compressional forces in continental collisions may cause the compressed region to thicken and fold, with material forced both upwards and downwards. Since the less dense continental crust "floats" (cf iceberg) 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 (see isostasy) of a much greater volume forced downward into the mantle. Thus the continental crust is normally much thicker under mountains ( sometimes called "mountain roots"),[15] compared to lower lying areas. However, in many continental collisions (e.g. the Himalayas) part of one continent may simply override the other, crumpling in the process with the overridden crust forming much of the support. Mountains may similarly be partly supported by oceanic crust subducted beneath the continental crust (e.g. the Andes as the Nazca plate flows beneath the South American Plate).

Fault-block mountain

Block mountains are created when large areas are widely broken up by faults creating large vertical displacements. This occurrence is fairly common. 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, the Basin and Range province of Western North America and the Rhine valley. These areas often occur when the regional stress is extensional and the crust is thinned.

Rock that does not fault may 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 Jura Mountains are an example of folding. Over time, erosion can bring about an inversion of relief: the soft upthrust rock is worn away so the anticlines are actually lower than the tougher, more compressed rock of the synclines.

Volcanoes

Some isolated mountains are produced by volcanoes, including many apparently small islands or seamounts that reach a great height above the ocean floor.

Mid-ocean ridges

The mid-ocean ridges formed during sea-floor spreading are often referred to as undersea mountain ranges due to their bathymetric prominence.

See also

The Zugspitze, the highest mountain in Germany

Notes

  1. ^ a b Gerrard, A. J. 1990. Mountain Environments
  2. ^ Blyth, S., Groombridge, B., Lysenko, I., Miles, L. & Newton, A. (2002). "Mountain Watch". UNEP World Conservation Monitoring Centre, Cambridge, UK. http://www.unep-wcmc.org/mountains/mountain_watch/pdfs/WholeReport.pdf. Retrieved 2009-02-17. 
  3. ^ Panos (2002). "High Stakes". http://www.panos.org.uk/?lid=278. Retrieved 2009-02-17. 
  4. ^ "International Year of Freshwater 2003". http://www.wateryear2003.org/en/ev.php-URL_ID=3903&URL_DO=DO_TOPIC&URL_SECTION=201.html. Retrieved 2006-12-07. 
  5. ^ "The Mountain Institute". http://www.mountain.org/mountains/whymtns.cfm?slidepage=water. Retrieved 2006-12-07. 
  6. ^ a b "Biotic Communities of the Colorado Plateau: C. Hart Merriam and the Life Zones Concept". http://cpluhna.nau.edu/Biota/merriam.htm. Retrieved 30 January 2010. 
  7. ^ "Tree". Microsoft Encarta Reference Library 2003. Microsoft Corporation. 1993-2002. 60210-442-1635445-74407. 
  8. ^ "Mountain Environments". United Nations Environment Programme World Conservation Monitoring Centre. http://www.unep-wcmc.org/mountains/mountain_watch/pdfs/mountainEnvironments.pdf. Retrieved 30 January 2010. 
  9. ^ Taylor, Richard Cachor (2005). A Birder's Guide to Southeastern Arizona. American Birding Association. pp. 2–4. ISBN 1-878788-22-1. 
  10. ^ Tweit, Susan J. (1992). The Great Southwest Nature Factbook. Alaska Northwest Books. pp. 209–210. ISBN 0-88240-434-2. 
  11. ^ Lutgens, Frederick K.; Tarbuck, Edward J. (1998). The Atmosphere: An Introduction to Meteorology. Prentice Hall. pp. 15–17, 30–35, 38–40. ISBN 0-13-742974-6. 
  12. ^ "Temperature". Microsoft Encarta Reference Library 2003. 
  13. ^ "Atmosphere". Microsoft Encarta Reference Library 2003. 
  14. ^ Dommasch, Daniel O. (1961). Airplane Aerodynamics (3rd ed.). Pitman Publishing Co.. p. 22. 
  15. ^ Press, Frank and Siever, Raymond, Earth, W. H. Freeman, 4th ed., 1985, p. 413 ISBN 978-0-7167-1743-0

Further reading

  • Fraknoi, A., Morrison, D., & Wolff, S. (2004). Voyages to the Planets. 3rd Ed. Belmont: Thomson Books/Cole.



Translations:

Mountain

Top

Dansk (Danish)
n. - bjerg

idioms:

  • a mountain to climb    bestige et bjerg
  • mountain bike    mountainbike (cykel til hårdt terræn)
  • mountain chain    bjergkæde
  • mountain goat    bjergged
  • mountain lion    puma
  • mountain range    bjergkæde
  • move mountains    flytte bjerge

Nederlands (Dutch)
berg, barrière

Français (French)
n. - (lit) montagne, mont, (fig) montagne, monceau, (Écon) excédent

idioms:

  • have a mountain to climb    avoir de grosses difficultés à surmonter
  • mountain bike    vélo tout terrain VTT
  • mountain chain    chaîne de montagnes
  • mountain goat    chèvre chamoisée
  • mountain lion    puma, couguar
  • mountain range    chaîne de montagne
  • move mountains    déplacer des montagnes

Deutsch (German)
n. - Berg

idioms:

  • have a mountain to climb    harte Arbeit
  • mountain bike    Mountain-Bike
  • mountain chain    Gebirgskette
  • mountain goat    Schneeziege
  • mountain lion    Puma
  • mountain range    Gebirgszug
  • move mountains    Berge versetzen

Ελληνική (Greek)
n. - (γεωγρ.) βουνό, όρος, (μτφ.) σωρός, πλήθος, τεράστιος όγκος, βουνό, (επίθ.) βουνίσιος, ορεινός

idioms:

  • a mountain to climb    δυσχερές έργο
  • mountain bike    ποδήλατο κατάλληλο για χώμα
  • mountain chain    οροσειρά
  • mountain goat    αγριοκάτσικο, κρι-κρι
  • mountain lion    (ζωολ.) κούγκαρ, πούμα
  • mountain range    οροσειρά
  • move mountains    μετακινώ βουνά

Italiano (Italian)
montagna

idioms:

  • a mountain to climb    una vetta da scalare
  • mountain bike    bicicletta da montagna
  • mountain chain    catena di montagne
  • mountain goat    capra selvatica
  • mountain lion    puma
  • mountain range    catena di montagne
  • move mountains    muover mari e monti

Português (Portuguese)
n. - montanha (f)

idioms:

  • a mountain to climb    obstáculo a vencer
  • mountain bike    bicicleta de montanha (f)
  • mountain chain    cadeia de montanhas (f)
  • mountain goat    cabrito montês (m) (Zool.)
  • mountain lion    leão da montanha (m) (Zool.)
  • mountain range    cordilheira (f)
  • move mountains    mover montanhas

Русский (Russian)
гора, множество

idioms:

  • a mountain to climb    чрезвычайно сложная проблема
  • mountain bike    горный велосипед
  • mountain chain    горная цепь
  • mountain goat    горный козел
  • mountain lion    пума
  • mountain range    горная гряда
  • move mountains    сделать невозможное

Español (Spanish)
n. - montaña, montón, monte, cordillera

idioms:

  • have a mountain to climb    será muy difícil llegar al objetivo, reto, desafío, tener que superar un reto
  • mountain bike    bicicleta de montaña
  • mountain chain    sierra, cordillera
  • mountain goat    cabra montañesa
  • mountain lion    puma
  • mountain range    sierra, cordillera
  • move mountains    hacer esfuerzos extraordinarios

Svenska (Swedish)
n. - berg, fjäll

中文(简体)(Chinese (Simplified))
山, 山脉

idioms:

  • a mountain to climb    大量, 一堆, 困难重重
  • mountain bike    登山车
  • mountain chain    山脉
  • mountain goat    野生白山羊
  • mountain lion    美洲狮
  • mountain range    山脉
  • move mountains    竭尽全力

中文(繁體)(Chinese (Traditional))
n. - 山, 山脈

idioms:

  • a mountain to climb    大量, 一堆, 困難重重
  • mountain bike    登山車
  • mountain chain    山脈
  • mountain goat    野生白山羊
  • mountain lion    美洲獅
  • mountain range    山脈
  • move mountains    竭盡全力

한국어 (Korean)
n. - 산

idioms:

  • a mountain to climb    등산

日本語 (Japanese)
n. - 山, 山脈, 多量

idioms:

  • a mountain to climb    登山用の山
  • mountain bike    マウンテンバイク
  • mountain chain    山脈
  • mountain goat    シロイワヤギ, ヤギ羚羊
  • mountain lion    ピューマ
  • mountain massif    大山塊
  • mountain range    山脈

العربيه (Arabic)
‏(الاسم) جبل‏

עברית (Hebrew)
n. - ‮הר, כמות עצומה, ערימה גדולה, מלאי גדול‬


Post a question - any question - to the WikiAnswers community:

Copyrights:

Mentioned in