The TIBETAN PLATEAU (Tibetan : བོད་ས་མཐོ།, Wylie
: _bod sa mtho_), also known in
China as the QINGHAI–TIBET PLATEAU
or the QINGZANG PLATEAU (Chinese : 青藏高原; pinyin : _Qīngzàng
Gāoyuán_) or HIMALAYAN PLATEAU, is a vast elevated plateau in
Central Asia and
East Asia , covering most of the Tibet
Autonomous Region and
Qinghai Province in western
China , as well as
Jammu and Kashmir
Jammu and Kashmir state of India. It stretches
approximately 1,000 kilometres (620 mi) north to south and 2,500
kilometres (1,600 mi) east to west. With an average elevation
exceeding 4,500 metres (14,800 ft), the Tibetan
Plateau is sometimes
called "the Roof of the World" and is the world's highest and largest
plateau, with an area of 2,500,000 square kilometres (970,000 sq mi)
(about five times the size of
Metropolitan France ). Sometimes termed
the THIRD POLE, the Tibetan
Plateau contains the headwaters of the
drainage basins of most of the streams in surrounding regions. Its
tens of thousands of glaciers and other geographical and ecological
features serve as a "water tower" storing water and maintaining flow .
The impact of global warming on the Tibetan
Plateau is of intense
* 1 Description
Geology and geological history
* 3 Animal and plant life
* 3.1 Nomadic culture
* 4 Impact on other regions
* 4.1 Role in monsoons
* 5 Glaciology: the Ice Age and at present
* 5.1 Effect of climate change
* 6 See also
* 7 Notes
* 8 References
* 9 External links
Plateau is surrounded by massive mountain ranges. The
plateau is bordered to the south by the inner Himalayan range , to the
north by the
Kunlun Range which separates it from the
Tarim Basin ,
and to the northeast by the
Qilian Range which separates the plateau
Hexi Corridor and
Gobi Desert . To the east and southeast the
plateau gives way to the forested gorge and ridge geography of the
mountainous headwaters of the
Mekong , and
Yangtze rivers in
northwest Yunnan and western
Hengduan Mountains ). In the
west the curve of the rugged
Karakoram range of northern Kashmir
embraces the plateau. The
Indus River originates in the western
Plateau in the vicinity of Lake Mansarovar . Tibetan
Buddhist stupa and houses outside the town of Ngawa , on the Tibetan
Plateau is bounded in the north by a broad escarpment
where the altitude drops from around 5,000 metres (16,000 ft) to 1,500
metres (4,900 ft) over a horizontal distance of less than 150
kilometres (93 mi). Along the escarpment is a range of mountains. In
the west the
Kunlun Mountains separate the plateau from the Tarim
Basin. About halfway across the Tarim the bounding range becomes the
Altyn-Tagh and the Kunluns, by convention, continue somewhat to the
south. In the 'V' formed by this split is the western part of the
Qaidam Basin . The
Altyn-Tagh ends near the Dangjin pass on the
Golmud road. To the west are short ranges called the Danghe,
Yema, Shule, and Tulai Nanshans. The easternmost range is the Qilian
Mountains. The line of mountains continues east of the plateau as the
Qin Mountains which separate the
Ordos Region from
Sichuan . North of
the mountains runs the Gansu or
Hexi Corridor which was the main
silk-road route from
China proper to the West.
The plateau is a high-altitude arid steppe interspersed with mountain
ranges and large brackish lakes. Annual precipitation ranges from 100
to 300 millimetres (3.9 to 11.8 in) and falls mainly as hail. The
southern and eastern edges of the steppe have grasslands which can
sustainably support populations of nomadic herdsmen, although frost
occurs for six months of the year.
Permafrost occurs over extensive
parts of the plateau. Proceeding to the north and northwest, the
plateau becomes progressively higher, colder and drier, until reaching
Changthang region in the northwestern part of the plateau.
Here the average altitude exceeds 5,000 metres (16,000 ft) and winter
temperatures can drop to −40 °C (−40 °F). As a result of this
extremely inhospitable environment, the
Changthang region (together
with the adjoining Kekexili region) is the least populous region in
Asia, and the third least populous area in the world after Antarctica
Greenland . NASA satellite image of the
south-eastern area of Tibetan Plateau.
Brahmaputra River is in the
GEOLOGY AND GEOLOGICAL HISTORY
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Geology of the
Yamdrok tso is one of the
three largest sacred lakes in Tibet.
The geological history of the Tibetan
Plateau is closely related to
that of the Himalayan mountain range. The
Himalayas are among the
youngest mountain ranges on the planet and consist mostly of uplifted
sedimentary and metamorphic rock . Their formation is a result of a
continental collision or orogeny along the convergent boundary between
Indo-Australian Plate and the
Eurasian Plate .
The collision began in the Upper
Cretaceous period about 70 million
years ago, when the north-moving
Indo-Australian Plate , moving at
about 15 cm (6 in) per year, collided with the
Eurasian Plate . About
50 million years ago, this fast moving Indo-Australian plate had
completely closed the
Tethys Ocean , the existence of which has been
determined by sedimentary rocks settled on the ocean floor, and the
volcanoes that fringed its edges. Since these sediments were light,
they crumpled into mountain ranges rather than sinking to the floor.
The Indo-Australian plate continues to be driven horizontally below
Tibetan plateau , which forces the plateau to move upwards; the
plateau is still rising at a rate of approximately 5 mm (0.2 in) per
ANIMAL AND PLANT LIFE
Pastoral nomads camping near
Tibet's elevation and lack of precipitation produces an alpine tundra
environment, which reduces species diversity .
Tibet hosts species of
wolf , snow leopard , wild yak , wild donkey , cranes , vultures ,
hawks , geese , snakes , and buffalo . One notable animal is the
high-altitude jumping spider , that can live at elevations of over
6,500 metres (21,300 ft).
Nomads on the Tibetan
Plateau and in the
Himalayas are the remainders
of nomadic practices historically once widespread in
Pastoral nomads constitute about 40% of the ethnic Tibetan
population. The presence of nomadic peoples on the plateau is
predicated on their adaptation to survival on the world's grassland by
raising livestock rather than crops, which are unsuitable to the
terrain. Archaeological evidence suggests that the colonization
leading to the full-time occupation of the plateau occurred much later
than the previously thought 30,000 years ago.
IMPACT ON OTHER REGIONS
ROLE IN MONSOONS
Monsoon Natural-colour satellite image of the
Monsoons are caused by the different amplitudes of surface
temperature seasonal cycles between land and oceans. This differential
warming happens because heating rates differ between land and water.
Ocean heating is distributed vertically through a "mixed layer" that
may be fifty meters deep through the action of wind and
buoyancy-generated turbulence , whereas the land surface conducts heat
slowly, with the seasonal signal penetrating only a meter or so.
Additionally, the specific heat capacity of liquid water is
significantly greater than that of most materials that make up land.
Together, these factors mean that the heat capacity of the layer
participating in the seasonal cycle is much larger over the oceans
than over land, with the consequence that the land warms and cools
faster than the ocean. In turn, air over the land warms faster and
reaches a higher temperature than does air over the ocean. The warmer
air over land tends to rise, creating an area of low pressure . The
pressure anomaly then causes a steady wind to blow toward the land,
which brings the moist air over the ocean surface with it. Rainfall is
then increased by the presence of the moist ocean air. The rainfall is
stimulated by a variety of mechanisms, such as low-level air being
lifted upwards by mountains, surface heating, convergence at the
surface, divergence aloft, or from storm-produced outflows near the
surface. When such lifting occurs, the air cools due expansion in
lower pressure, which in turn produces condensation and precipitation.
In winter, the land cools off quickly, but the ocean maintains the
heat longer. The hot air over the ocean rises, creating a low-pressure
area and a breeze from land to ocean while a large area of drying high
pressure is formed over the land, increased by wintertime cooling.
Monsoons are similar to sea and land breezes , a term usually
referring to the localized, diurnal cycle of circulation near
coastlines everywhere, but they are much larger in scale, stronger and
seasonal. The seasonal monsoon wind shift and weather associated with
the heating and cooling of the
Tibetan plateau is the strongest such
monsoon on Earth.
GLACIOLOGY: THE ICE AGE AND AT PRESENT
Himalayas as seen from space looking south from over the
Tibet is an important heating surface of the atmosphere.
However, during the
Last Glacial Maximum , an approximately 2,400,000
square kilometres (930,000 sq mi) ice sheet covered the plateau.
Due to its great extent, this glaciation in the subtropics was an
important element of radiative forcing . With a much lower latitude,
the ice in
Tibet reflected at least 4 times more radiation energy per
unit area into space than ice at higher latitudes . Thus, while the
modern plateau heats the overlying atmosphere, during the Last Ice Age
it helped to cool it.
This cooling had multiple effects on regional climate. Without the
thermal low pressure caused by the heating, there was no monsoon over
the Indian subcontinent. This lack of monsoon caused extensive
rainfall over the
Sahara desert , expansion of the
Thar desert , more
dust deposited into the
Arabian Sea , and a lowering of the biotic
life zones on the Indian subcontinent. Animals responded to this shift
in climate, with the
Javan Rusa deer migrating into India.
In addition, the glaciers in
Tibet created meltwater lakes in the
Qaidam Basin , the
Tarim Basin , and the
Gobi Desert , despite the
strong evaporation caused by the low latitude. Silt and clay from the
glaciers accumulated in these lakes; when the lakes dried at the end
of the ice age, the silt and clay were blown by the downslope wind off
the Plateau. These airborne fine grains produced the enormous amount
of loess in the Chinese lowlands.
EFFECT OF CLIMATE CHANGE
Plateau contains the world's third-largest store of ice.
Qin Dahe, the former head of the
China Meteorological Administration,
issued the following assessment in 2009:
"Temperatures are rising four times faster than elsewhere in China,
and the Tibetan glaciers are retreating at a higher speed than in any
other part of the world." "In the short term, this will cause lakes to
expand and bring floods and mudflows." "In the long run, the glaciers
are vital lifelines for Asian rivers, including the Indus and the
Ganges. Once they vanish, water supplies in those regions will be in
Geography of Tibet
* Tibetan People
* Tibetan Culture
* Tibetan Alphabet
* Incorporation of
Tibet into the People\'s Republic of
Tibet sovereignty debate
Central Tibetan Administration
Central Tibetan Administration general election, 2016
* Parliament of the
Central Tibetan Administration
* Tibetan Diaspora
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6, 2012). _Regional Hydrological Response to Climate Change_. Springer
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* ^ "The Tibetan Empire in
Central Asia (Christopher Beckwith)".
* ^ Hopkirk 1983, p. 1
* ^ Peregrine, Peter Neal & Melvin Ember, etc. (2001).
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Extensional Tectonics During the India-
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* ^ "Natural World: Deserts". National Geographic. Archived from
the original on 2006-01-12.
* ^ Leslie Hook (August 30, 2013). "Tibet: life on the climate
front line". _The Financial Times_. Retrieved September 1, 2013.
* ^ Liu, Xiaodong; Chen (2000). "Climatic warming in the Tibetan
Plateau during recent decades". _International Journal of
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* ^ Ni, Jian (2000). "A Simulation of Biomes on the Tibetan Plateau
and Their Responses to Global Climate Change". _Mountain Research and
Development_. 20 (1): 80–89. doi :10.1659/0276-4741(2000)0202.0.CO;2
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* ^ Cheng, Guodong; Wu (8 June 2007). "Responses of permafrost to
climate change and their environmental significance, Qinghai-Tibet
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* ^ Yang, Qinye; Zheng, Du (2004). _A Unique Geographical Unit_.
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* ^ "Wild China: The Tibetan Plateau". _The Nature of Things_.
Canadian Broadcasting Company. Retrieved 2013-03-21.
* ^ David Miller. "Nomads of
Tibet and Bhutan". asinart.com.
* ^ In pictures: Tibetan nomads
* ^ _A_ _B_ Oracle Thinkquest Educati