Mountains : Glossary

There are 30 documents in this section.

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  • Valley

    30 April 2001

    Depression in the land surface often occupied by a river. In geology, the chief agency in the formation of a valley is erosion carried on by the running streams and assisted by the natural decay or weathering of the rocks in which the channels lie."Valley," Microsoft® Encarta® Online Encyclopedia 2001http://encarta.msn.co.uk © 1997-2001 Microsoft Corporation. All rights reserved.

  • Mountains

    30 April 2001

    Name usually applied to any region of land that is raised rather steeply above the surrounding terrain. Mountains are distinguishable from plateaux by their usually limited summit area; and they are distinguishable from what are comonly called hills by their generally higher elevation. The elevation, or altitude, of a mountain is given as the height of the summit above sea level. Therefore, a mountain with an elevation of, say, 4,000 m (13,100 ft) may rise to only 3,000 m (9,840 ft) above the surrounding land.Mountains are normally found in groups or ranges consisting of peaks, ridges, and intermontane valleys. Apart from certain mountains that occur singly, the smallest unit is the range, comprising either a single complex ridge or a series of ridges generally alike in origin, age, and form. Several closely related ranges in a parallel alignment or chain-like cluster are known as a mountain system; an elongated series of systems forms a mountain chain; and an extensive complex of ranges, systems, and chains is known as a belt, or cordillera."Mountains," Microsoft® Encarta® Online Encyclopedia 2001http://encarta.msn.co.uk © 1997-2001 Microsoft Corporation. All rights reserved.

  • Erosion

    30 April 2001

    Natural physical and chemical processes by which the soil and the rocks of the Earth's crust are continuously abraded and corroded. Most erosion results from the combined activity of several factors, such as heat, cold, gases, water, wind, gravity, and plant life. In some regions one of these may predominate, such as wind in arid areas. Erosion is grouped into two major divisions: geological erosion, which affects rocks as well as soil, and soil erosion."Erosion," Microsoft® Encarta® Online Encyclopedia 2001http://encarta.msn.co.uk © 1997-2001 Microsoft Corporation. All rights reserved.

  • Plateau

    30 April 2001

    In geology, extensive land formation. The top is flat or sloping; the elevation, from a few hundred to several thousand metres. A plateau is larger than a mesa or butte. Plateaux are often riven by erosion into deep canyons. Major plateaux in North America are the Columbia and Colorado plateaux."Plateau," Microsoft® Encarta® Online Encyclopedia 2001http://encarta.msn.co.uk © 1997-2001 Microsoft Corporation. All rights reserved.

  • Upland

    30 April 2001

    Higher or inland parts of a country.

  • Landslide

    30 April 2001

    Descent of a mass of earth and rock down a mountain slope. Landslides may occur when water from rain and melting snow sinks through the earth on top of a slope, seeps through cracks and pore spaces in underlying sandstone, and encounters a bed of shale inclined towards the valley. The water collects along the upper surface of the shale, which it softens to form slippery clay. If the support is sufficiently weakened, a mass of earth and rock slides down along the well-lubricated bedding of shale. Some great landslide masses move slowly and spasmodically for years, causing little destruction."Landslide," Microsoft® Encarta® Online Encyclopedia 2001http://encarta.msn.co.uk © 1997-2001 Microsoft Corporation. All rights reserved.

  • Altitude

    30 April 2001

    Elevation above mean sea level. Usually the altitude of a fixed point, such as a mountain peak, is determined most accurately by triangulation with optical instruments. The altitude of an aircraft, however, is measured most accurately by means of a radio altimeter."Altitude (geography)," Microsoft® Encarta® Online Encyclopedia 2001 "Altitude (geography)," Microsoft® Encarta® Online Encyclopedia 2001http://encarta.msn.co.uk © 1997-2001 Microsoft Corporation. All rights reserved.

  • Endemic species

    16 March 2001

    Those species that are native to a certain region with restricted distributions and within in restricted range. Outside that restricted range (such as an ecosystem island, or within country boundaries) an endemic species is found nowhere else on earth.

  • Habitat

    16 March 2001

    The particular environment (e.g. tropical moist forest) in which a species or breeding population naturally lives.

  • Flora

    16 March 2001

    The combination of plants in a particular area. Each biome has a characteristic flora.

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