Mountains

Glaciers and river systems

noreply@blogger.com (sadaf fahim) — Wed, 16 May 2012 06:00:00 +0000

Glaciers and river systems

The Himalayan range encompasses about 15,000 glaciers, which store about 12,000 km3 of freshwater. The 70 km-long Siachen Glacier at the India-Pakistan border is the second longest glacier in the world outside the polar region. Some of the other more famous glaciers include the Gangotri and Yamunotri (Uttarakhand), Nubra, Biafo and Baltoro (Karakoram region), Zemu (Sikkim) and Khumbu glaciers (Mount Everest region). The higher regions of the Himalayas are snowbound throughout the year, in spite of their proximity to the tropics, and they form the sources for several large perennial rivers, most of which combine into two large river systems: The western rivers combine into the Indus Basin, of which the Indus River is the largest. The Indus begins in Tibet at the confluence of Sengge and Gar rivers and flows southwest through India and then through Pakistan to the Arabian Sea. It is fed by the Jhelum, the Chenab, the Ravi, the Beas, and the Sutlej rivers, among others. Most of the other Himalayan rivers drain the Ganges-Brahmaputra Basin. Its two main rivers are the Ganges and the Brahmaputra and the Yamuna, among other tributaries. The Brahmaputra originates as the Yarlung Tsangpo River in western Tibet, and flows east through Tibet and west through the plains of Assam. The Ganges and the Brahmaputra meet in Bangladesh, and drain into the Bay of Bengal through the world's largest river delta.The eastern-most Himalayan rivers feed the Ayeyarwady River, which originates in eastern Tibet and flows south through Myanmar to drain into the Andaman Sea. The Salween, Mekong, Yangtze and the Huang He (Yellow River) all originate from parts of the Tibetan plateau that are geologically distinct from the Himalaya mountains, and are therefore not considered true Himalayan rivers. Some geologists refer to all the rivers collectively as the circum-Himalayan rivers. In recent years, scientists have monitored a notable increase in the rate of glacier retreat across the region as a result of global climate change.Although the effect of this will not be known for many years, it potentially could mean disaster for the hundreds of millions of people who rely on the glaciers to feed the rivers of northern India during the dry seasons.

Mount Abu

noreply@blogger.com (sadaf fahim) — Tue, 15 May 2012 08:18:00 +0000

Mount Abu

Mount Abu About this sound pronunciation (help·info) is the highest peak in the Aravalli Range of Rajasthan state in western India. It is located in Sirohi district. Mount Abu is 58 km from Palanpur (Gujarat). The mountain forms a distinct rocky plateau 22 km long by 9 km wide. The highest peak on the mountain is Guru Shikhar, at 1,722 metres (5,650 ft) above sea level. It is referred to as 'an oasis in the desert', as its heights are home to rivers, lakes, waterfalls and evergreen forests. The ancient name of Mount Abu is "Arbudaanchal" Arbudaanchal

Contents [hide]
* 1 History o
1.1 The Gurjars and Arbuda Mountain o
Nakki Lake after sunset
1.2 Mythology
* 2 Tourist attractions
* 3 Climate
* 4 Transportation
* 5 Demographics
* 6 References
* 7 External links Nakki Lake after sunset

History

The Gurjars and Arbuda Mountain

The Arbuda Mountains (Mount Abu) region is said to be original abode of the famous Gurjaras.The association of the Gurjars with the mountain is noticed in many inscriptions and epigraphs including Tilakamanjari of Dhanpala. These Gurjars (Gujars or Gujjars) migrated from Arbuda mountain region and as early as sixth century A.D, they set up one or more principalities in Rajasthan and Gujarat. Almost all or a larger part of Rajasthan and Gujarat had been known as Gurjaratra (country ruled or protected by the Gurjars) or Gurjarabhumi (land of the Gurjars) for centuries prior to Mughal period.The conquest of Mount Abu in 1311 by Rao Lumba of Deora-Chauhan dynasty brought to an end the reign of the Parmars and also marked the decline of Mount Abu. He shifted the capital city to Chandravati in the plains. After the destruction of Chandravati in 1405, Rao Shasmal made Sirohi his headquarters.Later it was leased by the British government from the then Maharaja of Sirohi for use as the headquarter of the resident to Rajputana (another name for Rajasthan). [edit]

Mythology

In the Puranas, the region has been referred to as Arbudaranya ("forest of Arbhuda") and 'Abu' is a diminutive of this ancient name. It is believed that sage Vasishtha retired to the southern spur at Mount Abu following his differences with sage Vishvamitra. There is another mythology according to which a serpent named "Arbuda" saved the life of Nandi - Lord Shiva's bull. The incident happened on the mountain which is currently known as mount Abu and so the mountain is named "Arbudaranya" after that incident which gradually became Abu.

Mount Abu
— city —
Mount Abu Location of Mount Abu in Rajasthan and India
Coordinates	24°35′33″N 72°42′30″E / 24.5925°N 72.7083°E / 24.5925; 72.7083Coordinates: 24°35′33″N 72°42′30″E / 24.5925°N 72.7083°E / 24.5925; 72.7083
Country	India
State	Rajasthan
District(s)	Sirohi
Population • Density	30,000 (2011^[update]) • 50 /km² (129 /sq mi)
Time zone	IST (UTC+05:30)
Area • Elevation	• 1,164 metres (3,819 ft)

Tourist attractions

Sunset at Mt. Abu

The town of Mount Abu, the only hill station in Rajasthan, is located at an elevation of 1,220 m (4,003 ft). It has been a popular retreat from the heat of Rajasthan and neighbouring Gujarat for centuries. The Mount Abu Wildlife Sanctuary was established in 1960 and covers 290 km² of the mountain. The mountain is also home to several Hindu temples, including the Adhar Devi Temple, carved out of solid rock; the Shri Raghunathji Temple; and a shrine and temple to Dattatreya built atop the Guru Shikhar peak and a number of Jain temples including Dilwara, a complex of temples carved of white marble that was built between the 11th and 13th centuries AD. The oldest of these is the Vimal Vasahi temple, built in 1021 AD by Vimal Shah and dedicated to the first of the Jain Tirthankaras and they include the Achaleswar Mahadev Temple (1412) and the Kantinath Temple (1513). It is also the location of "Madhuban", the headquarters of the Brahma Kumaris World Spiritual University. Nakki Lake with the Maharaja Jaipur Palace and Toad Rock The Achalgarh fort, built in the 14th century by Rana Kumbha of Mewar is nearby and at its center is the popular visitor attraction of the Nakki Lake. There is the Toad Rock on a hill near the lake. The Durga temple, Ambika Mata Temple lies in a cleft of rock in Jagat, just outside of Mount Abu.

Climate

Summer Summer season prevails from mid of April to mid of June when average Maximum temperature remains around 36 °C. Therefore it will be better if you bring light cotton clothes. These clothes are fit for the summers of Mount Abu. Monsoon Due to its relief and geographical conditions, it rains well in Mount Abu during the monsoons. During the rainy season even the temperature falls down. Normal summer clothing will do. It is wiser to carry an umbrella in order to avoid being caught at the wrong side of monsoon.
Winter Winters are cool in Mount Abu, with mercury hovering around 16 °C to 22 °C. Nights are really chilly and average night temperature is around 4 to 12 °C. Nevertheless, there are instances when the temperature has dipped to as low as −2 to −3 °C. Heavy winter clothing is preferable. You can include long coats and outsiders in your luggage. In daytime, light pullovers are sufficient.

Transportation

The nearest railway station is at Abu Road, in the lowlands 27 km southeast of Mount Abu town. The station is on the main Indian Railways line between Delhi,Palanpur and Ahmedabad.Its is very well connected with daily travels bus service from Ahmedabad and other big cities of Gujarat. It has regular trains for Jaipur, Jodhpur, Udaipur, Ajmer, Indore, Agra, Bhopal, Gwalior, Jabalpur, Ujjain, Delhi, Mumbai, Kolkata, Chennai, Hyderabad, Bangalore, Ahmedabad, Pune and weekly trains from Trivandrum(Kochu Veli)
http://en.wikipedia.org/wiki/Mount_Abu

Glaciers and river systems

noreply@blogger.com (sadaf fahim) — Sat, 12 May 2012 08:16:00 +0000

Glaciers and river systems

Lowland forests

noreply@blogger.com (sadaf fahim) — Sat, 12 May 2012 08:11:00 +0000

Lowland forests

On the Indo-Gangetic plain at the base of the mountains, an alluvial plain drained by the Indus and Ganges-Brahmaputra river systems, vegetation varies from west to east with rainfall. The xeric Northwestern thornscrub forests occupy the plains of Pakistan and the Indian Punjab. Further east lie the Upper Gangetic plains moist deciduous forests of Uttarakhand and Uttar Pradesh and Lower Gangetic plains moist deciduous forests of Bihar and West Bengal. These are monsoon forests, with drought-deciduous trees that lose their leaves during the dry season. The moister Brahmaputra Valley semi-evergreen forests occupy the plains of Assam.

The Terai belt

Above the alluvial plain lies the Terai strip, a seasonally marshy zone of sand and clay soils. The Terai has higher rainfall than the plains, and the downward-rushing rivers of the Himalaya slow down and spread out in the flatter Terai zone, depositing fertile silt during the monsoon season and receding in the dry season. The Terai has a high water table due to groundwater percolating down from the adjacent zone. The central part of the Terai belt is occupied by the Terai-Duar savanna and grasslands, a mosaic of grasslands, savannas, deciduous and evergreen forests that includes some of the world's highest grasslands. The grasslands of the Terai belt are home to the Indian rhinoceros (Rhinoceros unicornis).

Bhabhar belt

Above the Terai belt is an upland zone known as the Bhabhar, a zone of porous and rocky soils made up of debris washed down from the higher ranges. The Bhabhar and the lower Shiwalik ranges have a subtropical climate. The Himalayan subtropical pine forests occupy the western end of the subtropical belt, with forests dominated by Chir Pine (Pinus roxburghii). The central part of the range is home to the Himalayan subtropical broadleaf forests, dominated by the sal tree (Shorea robusta). They are at the foot of the

Himalayas where the Himalayan streams descend on to the plains.

Shiwalik Hills

Also called Churia or Margalla Hills, Sivalik Hills is an intermittent outermost range of foothills extending across the Himalayan region through Pakistan, India, Nepal and Bhutan. This region consists of many sub-ranges. Summits are generally 600 to 1,200 meters (2,000 to 3,900 ft). Steeper southern slopes form along a fault zone called Himalayan Frontal Thrust (HFT); northern slopes are gentler. Permeable conglomerates and other rocks allow rainwater to percolate downslope into the Bhabhar and Terai, supporting only scrubby forests upslope. The Himalayan subtropical pine and broadleaf forests continue here.

Inner Terai or Dun Valleys

The Inner Terai valleys are open valleys north of Shiwalik Hills or nestled between Shiwalik subranges. Examples include Dehra Dun in India and Chitwan in Nepal. Himalayan subtropical broadleaf forests grow here.
http://en.wikipedia.org/wiki/Himalayas

Himalayas

noreply@blogger.com (sadaf fahim) — Sat, 12 May 2012 07:57:00 +0000

Himalayas

The Himalaya Range or Himalaya Mountains (play /ˌhɪməˈleɪ.ə/ or /hɪˈmɑːləjə/; Sanskrit: Devanagari: हिमालय, literally "abode of snow"), usually called the Himalayas or Himalaya for short, is a mountain range immediately at the north of the Indian subcontinent. By extension, it is also the name of a massive mountain system that includes the Karakoram, the Hindu Kush, and other, lesser, ranges that extend out from the Pamir Knot. Together, the Himalayan mountain system is the world's highest, and home to the world's highest peaks, the Eight-thousanders, which include Mount Everest and K2. To comprehend the enormous scale of this mountain range, consider that Aconcagua, in the Andes, at 6,962 metres (22,841 ft) is the highest peak outside Asia, whereas the Himalayan system includes over 100 mountains exceeding 7,200 m (23,600 ft).[3] However the Alleghenian mountains, formed during the formation of Pangaea, likely rivalled or exceeded the Himalayas in height.The main Himalayan range runs west to east, from the Indus river valley to the Brahmaputra river valley, forming an arc 2,400 km (1,500 mi) long, which varies in width from 400 km (250 mi) in the western Kashmir-Xinjiang region to 150 km (93 mi) in the eastern Tibet-Arunachal Pradesh region. The range consists of three coextensive sub-ranges, with the northernmost, and highest, known as the Great or Inner Himalayas. Some of the world's major river systems arise in the Himalayas, and their combined drainage basin is home to some 3 billion people (almost half of Earth's population) in 18 countries. The Himalayas have profoundly shaped the cultures of South Asia; many Himalayan peaks are sacred in Hinduism, Buddhism and Sikhism. Geologically, the origin of the Himalayas is the impact of the Indian tectonic plate traveling northward at 15 cm per year to impact the Eurasian continent, with first contact about 70 million years ago, and with movement continuing today. The formation of the Himalayan arc peaks eventually resulted from this, since the lighter rock of the seabeds of that time were easily uplifted into mountains. An often-cited fact used to illustrate this process is that the summit of Mount Everest is made of marine limestone.

http://en.wikipedia.org/wiki/Himalayas

References

noreply@blogger.com (sadaf fahim) — Sat, 12 May 2012 07:37:00 +0000

References

Krulwich, Robert (April 7, 2007). "The 'Highest' Spot on Earth?". Retrieved 21 March 2009. ^ For Nepal, the heights indicated on the Nepal Topographic Maps are followed. For China and the Baltimore Karakoram, the heights are those of "The Maps of Snow Mountains in China". For the Hi spar Karakorum the heights on a Russian 1:100,000 topo map seem to be more accurate than the customarily quoted heights probably based on US army maps from the 50s . Elsewhere, unless otherwise indicated, heights are those in Jill Neate's "High Asia". ^ Coordinates were established by comparing topographical maps with satellite images and SRTM-derived terrain maps. The terrain maps and satellite images often don't match exactly. An asterisk indicates that the map and image are shifted by more than 100 m and/or that the landscapes around the summit don't match. ^ The prominence data were extracted from a combination of maps and computer aided analysis of NASA's 3" SRTM data. Prominences over 1,450 m were copied from this website. ^ Here defined as the first higher mountain beyond the key saddle with at least 500 m prominence itself. ^ The number of ascents and failed attempts up to 2004 is extracted from the Alpine Club Himalayan index. These are the number of expeditions (not individuals) that announced their ascent or attempt in a journal. They are probably quite accurate for the rarely climbed peaks (though omissions were noted), but greatly underestimate the number of ascending parties on the easier and/or more popular mountains, like most eight-thousanders. For instance, Mt Everest has been scaled 2,251 times by individuals up to 2004 . ^ Given the large differences between multiple "final" measurements of Mt Everest, the traditional 8,848 m is listed. For more information, see Mount Everest#Measurement. ^ Everest IS parent to K2 by the definition of topographic prominence. See also, the discussion page. ^ The highest (Eastern) summit of Saser Kangri II has just recently been climbed, August 24th, 2011 The lower West peak, 2.5 km away, has been climbed in 1984 and twice since. ^ According to the 1996 Himalayan Journal (pp.29-36), the highest point of the Kabru massif (the North summit) was climbed by an Indian Army team in May 1994 ^ The height is unknown, but over 7,200 meters on both Chinese and Russian maps of the area. ^ The name and information about this summit was extracted from the May 2003 edition of Japanese Alpine News.
http://en.wikipedia.org/wiki/List_of_highest_mountains

Considerations

noreply@blogger.com (sadaf fahim) — Sat, 12 May 2012 07:29:00 +0000

Considerations

The dividing line between a mountain with multiple peaks and separate mountains is not always clear (see also Highest unclimbed mountain). A popular and intuitive way to distinguish mountains from subsidiary peaks is by their height above the highest saddle connecting it to a higher summit, a measure called topographic prominence or re-ascent (the higher summit is called the "parent peak"). A common definition of a mountain is a summit with 300 m (980 ft) prominence. Alternatively, a relative prominence (prominence/height) is used (usually 7-8%) to reflect that in higher mountain ranges everything is on a larger scale. The table below lists the highest 100 summits with at least 500 m (1,640 ft) prominence, approximating a 7% relative prominence. A drawback of a prominence-based list is that it may exclude well-known or spectacular mountains that are connected via a high ridge to a taller summit, like the Eiger or Nuptse. A few such peaks and mountains with nearly sufficient prominence are included but not numbered in this list. It is very unlikely that all given heights are correct to the nearest metre; indeed, the sea level is often problematic to define when a mountain is remote from the sea. Different sources often differ by many metres, and the heights given below may well differ from those elsewhere in this encyclopedia. As an extreme example, Ulugh Muztagh on the north Tibetan Plateau is often listed as 7,723 m (25,338 ft) to 7,754 m (25,440 ft), but appears to be only 6,973 m (22,877 ft) to 6,987 m (22,923 ft). Some mountains differ by > 100 m (330 ft) on different maps, while even very thorough current measurements of Mount Everest range from 8,840 m (29,003 ft) to 8,850 m (29,035 ft). These discrepancies serve to emphasize the uncertainties in the listed heights. Though some parts of the world, especially the most mountainous parts, have never been thoroughly mapped, it is unlikely that any mountains this high have been overlooked, because synthetic aperture radar can and has been used to measure altitudes of most otherwise inaccessible places. Still, heights and/or prominences may be revised, so that the order of the list may change and even "new" mountains could enter the list over time. To be safe, the list has been extended to include all >7,200 m (23,622 ft) peaks. The highest mountains above sea level are generally not the highest above the surrounding terrain. There is no precise definition of surrounding base, but Mount McKinley, Mount Kilimanjaro and Nanga Parbat are possible candidates for the tallest mountain on land by this measure. The bases of mountain islands are below sea level, and given this consideration Mauna Kea (4,207 m (13,802 ft) above sea level) is the world's tallest mountain and volcano, rising about 10,203 m (33,474 ft) from the Pacific Ocean floor. Ojos del Salado has the greatest rise on Earth— 13,420 m (44,029 ft) from the summit[citation needed] to the bottom of the Atacama Trench about 560 km (350 mi) away, though most of this rise is not part of the mountain. The highest mountains are also not generally the most voluminous. Mauna Loa (4,169 m (13,678 ft)) is the largest mountain on Earth in terms of base area (about 2,000 sq mi/5,200 km2) and volume (about 10,000 cu mi/42,000 km3), although, due to the intergrade of lava from Kilauea, Hualalai and Mauna Kea, the volume can only be estimated based on surface area and height of the edifice). Mt. Kilimanjaro is the largest non-shield volcano in terms of both base area (245 sq mi/635 km2) and volume (1,150 cu mi/4,793 km3). Mount Logan is the largest non-volcanic mountain in base area (120 sq mi/311 km2). The highest mountains above sea level are also not those with peaks farthest from the centre of the Earth, because the figure of the Earth is not spherical. Sea level closer to the equator is several miles farther from the centre of the Earth. The summit of Chimborazo, Ecuador's tallest mountain, is usually considered to be the farthest point from the Earth's centre, although the southern summit of Peru's tallest mountain, Huascarán, is another contender.[1] Both have elevations above sea level more than 2km less than that of Everest.

Geographical distribution

[show]Map of all coordinates from Google Map of first 200 coordinates from Bing Most mountains in the list are located in the Himalaya and Karakoram ranges. In fact, all 7,000 m (23,000 ft) peaks in the world are located in the centre of Asia (East Asia, Central Asia and South Asia) in a rectangle edged by Noshaq (7,492 m (24,580 ft)) on the Afghanistan-Pakistan border in the West, Peak Jengish Chokusu, (Tuōmù'ěr Fēng) (7,439 m (24,406 ft)) on the Kyrgyzstan - Xinjiang border to the North, Gongga Shan (Minya Konka) (7,556 m (24,790 ft)) in Sichuan to the East, and Kabru (7,412 m (24,318 ft)) on the Sikkim - Nepal border to the South. The locations of the highest mountains are shown on the composite satellite image of High Asia below. The numbers refer to the ranking in the list. For clarity, lower peaks with labels overlapping higher peaks are left out of the main image. The boxed regions are those with the highest density of summits and are enlarged in two separate images to show all peaks.

http://en.wikipedia.org/wiki/List_of_highest_mountains

Geology

noreply@blogger.com (sadaf fahim) — Sat, 12 May 2012 07:06:00 +0000

Geology

Main articles: Orogeny and Mountain formation 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

Blue Ridge Mountains in Shenandoah National Park, Virginia, USA 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.
http://en.wikipedia.org/wiki/Mountain

noreply@blogger.com (sadaf fahim) — Sat, 12 May 2012 06:56:00 +0000

Types

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.

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

Characteristics

noreply@blogger.com (sadaf fahim) — Sat, 12 May 2012 06:40:00 +0000

Characteristics

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. Just below the tree line, one may find subalpine forests of needleleaf trees, which can withstand cold, dry conditions. 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. 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. These isolated ecological systems, or microclimates, are known as sky islands. 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. 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). 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.
http://en.wikipedia.org/wiki/Mountain

Definition

noreply@blogger.com (sadaf fahim) — Sat, 12 May 2012 06:31:00 +0000

There is no universally accepted definition of a mountain. Elevation, volume, relief, steepness, spacing and continuity have been used as criteria for defining a mountain. In the Oxford English Dictionary a mountain is defined as "a natural elevation of the earth surface rising more or less abruptly from the surrounding level and attaining an altitude which, relatively to the adjacent elevation, is impressive or notable."Whether a landform is called a mountain may depend on 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 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. Most of the world's rivers are fed from mountain sources, and more than half of humanity depends on mountains for water.

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

Mountain

noreply@blogger.com (sadaf fahim) — Sat, 12 May 2012 06:05:00 +0000

A mountain is a large landforms that stretches above the surrounding land in a limited area usuallThere is no universally accepted definition of a mountain. Elevation, volume, relief, steepness, spacing and continuity have been used as criteria for defining a mountain. In the Oxford English Dictionary a mountain is defined as "a natural elevation of the earth surface rising more or less abruptly from the surrounding level and attaining an altitude which, relatively to the adjacent elevation, is impressive or notable. Whether a landform is called a mountain may depend on 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: 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. Most of the world's rivers are fed from mountain sources, and more than half of humanity depends on mountains for water.[4][5]y in the form of a peak. A mountain is generally steeper than a hill. The adjective montage is used to describe mountainous areas and things associated with them. The study of mountains is called Orthography. Exobiology deals with planetary mountains, which in that branch of science are usually called mantes (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 lithosphere plates.
http://en.wikipedia.org/wiki/Mountain