The 'Tibetan Plateau', also known as the 'Qinghai-Tibetan (Qingzang) Plateau' is a vast, elevated
plateau in
East Asia covering most of the
Tibet Autonomous Region and
Qinghai Province in the
People's Republic of China and
Ladakh in
Kashmir. It occupies an area of around 1,000 by 2,500 kilometers, and has an average elevation of over 4,500 meters. Called "the roof of the world," it is the highest and biggest
plateau in the world, with an area of 2.5 million square kilometers (about four times the size of
Texas or
France).
[1]
The Tibetan Plateau is surrounded by towering mountain ranges.
[2] It is bordered to the northwest by the
Kunlun Range which separates it from the
Tarim Basin, and to the northeast by the
Qilian Range which separates the plateau from the
Gobi Desert. In the south the plateau is delineated by the
Yarlung Tsangpo River valley which flows along the base of the
Himalayas, and by the vast
Indo-Gangetic Plain. To the east and southeast the plateau gives way to the forested gorge and ridge geography of the mountain headwaters of the
Salween,
Mekong, and
Yangtze rivers in western
Sichuan. In the west it is embraced by the curve of the rugged
Karakoram range of northern
Kashmir.
Description
The plateau is a high-altitude arid
steppe interspersed with mountain ranges and large brackish lakes. Annual precipitation ranges from 100mm to 300mm and falls mainly as
hailstorms. 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. Proceeding to the north and northwest, the plateau becomes progressively higher, colder, and drier, until reaching the remote
Kekexili region in the northwestern part of the plateau. Here the average altitude exceeds 5,000 meters (16,500 feet), the air contains only 60% of the oxygen of sea level, and year-round temperatures average -4°C, dipping to -40°C in winter. As a result of this extremely inhospitable environment, the Kekexili region is the least populated region in Asia, and the third least populated area in the world after
Antarctica and northern
Greenland.
The northern part of the plateau is convered with large areas of
permafrost, indicating the plateau has not completely emerged from the
glacial period.
[3]
Geology
The plateau was formed by the collision of the
Indo-Australian and
Eurasian tectonic plates in the
Cenozoic period (approximately 55 million years ago).
[4] The tectonic uplift of the plateau is thought to have had a significant effect on
climate change, and it is believed to affect the Asian
monsoon. In the
Indian monsoon season (June to October) when the winds bring humid, tropical air from the south, the Himalayas create a
rain shadow which makes northern India very wet and keeps the Tibetan Plateau very dry. As the winds continue over the plateau, they drop what little moisture remains in the air, becoming drier as they move northwards and creating deserts such as the
Taklamakan Desert and the
Gobi Desert.
[5]
Several of the world's longest rivers originate on the Tibetan Plateau. Between them, these rivers carry 25% of the world's
soil erosion to the sea. These include the
Yangtze River (or Chang Jiang),
Huang He (or Yellow River),
Indus River,
Satluj River,
Yarlung Tsangpo River ( known as the
Brahmaputra in India),
Mekong,
Irrawaddy River and the
Salween River.
Its many brackish lakes include
Tso Ngonpo,
Nam Tso,
Dagze Tso,
Lake Yamzho Yumco,
Lake Puma Yumco and
Lake Paiku.
The Tibetan Plateau has experienced four
glacial and three
interglacial periods during which the climate warmed.
[3]
See also
★
Geography of Tibet
★
Taklamakan Desert
★
Yunnan-Guizhou Plateau
★
Lop Nur
Notes
1. Natural World: Deserts
2. A Unique Geographical Unit
3. Widespread Glaciers and Frozen Soil
4. The New Largest Canyon in the World --The Great Canyon of Yarlung Tsangpo River (Tibet)
5. Leaf morphology and the timing of the rise of the Tibetan Plateau
6. Widespread Glaciers and Frozen Soil
References
★
The End of Earth's Summer
★
Long Rivers and Distant Sources
★
"Roof of the Earth" Offers Clues About How Our Planet Was Shaped
External links
★
Tibetan Plateau Perspectives
★
Leaf morphology and the timing of the rise of the Tibetan Plateau
★
Todays weather in the eastern Chang Tang
★
Protected areas of the Tibetan Plateau region
★
North Tibetan Plateau-Kunlun Mountains alpine desert