|
||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
|
||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
The Himalayas stretch across six nations: Bhutan, China, India, Nepal, Pakistan and Afghanistan. It is the source of three of the world's major river systems, the Indus Basin, the Ganga-Brahmaputra Basin and the Yangtze Basin. An estimated 750 million people live in the watershed area of the Himalayan rivers, which also includes Bangladesh.
EcologyThe flora and fauna of the Himalayas varies with climate, rainfall, altitude, and soils. The climate ranges from tropical at the base of the mountains to permanent ice and snow at the highest elevations. The amount of yearly rainfall increases from west to east along the front of the range. This diversity of climate, altitude, rainfall and soil conditions generates a variety of distinct plant and animal communities, or ecoregions. Lowland forestsOn 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 thorn scrub forests occupy the plains of Pakistan and the Indian Punjab. Further east lie the Upper Gangetic plains moist deciduous forests of 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
The Bhabhar beltAbove the Terai belt is an upland zone known as the Bhabhar, with porous and rocky soils, made up of debris washed down from the higher ranges. The Bhabhar and the lower Siwalik 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 sal (Shorea robusta). Montane forestsAt the middle elevations of the range, the subtropical forests yield to a belt of temperate broadleaf and mixed forests, with the Western Himalayan broadleaf forests at the western end of the range, and the Eastern Himalayan broadleaf forests in Assam and Arunachal Pradesh. Above the broadleaf forests are the Western and Eastern Himalayan subalpine conifer forests. Alpine shrub and grasslandsImage:India-view of shilla.jpg Shilla (7026 meters) above the Spiti Valley in India Above the tree line are the Northwestern, Western, and Eastern Himalayan alpine shrub and meadows, which yield to tundra in the higher Himalayan range. The alpine meadows are the summer habitat of the endangered Snow Leopard (Uncia uncia). The highest reaches of the range are above the permanent snow line. Origins and growthImage:Himalaya-formation.gif The 6,000 km plus journey of the India landmass (Indian Plate) before its collision with Asia (Eurasian Plate) about 40 to 50 million years ago. The Himalayas are among the youngest mountain ranges on the planet. According to the modern theory of plate tectonics, their formation is a result of a continental collision or orogeny along the convergent boundary between the 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/year, collided with the Eurasian Plate. By about 50 million years ago this fast moving Indo-Australian plate had completely closed the Tethys Ocean, whose existence 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 the Tibetan plateau, which forces the plateau to move upwards. The Arakan Yoma highlands in Myanmar and the Andaman and Nicobar Islands in the Bay of Bengal were also formed as a result of this collision. The Indo-Australian plate is still moving at 67 mm/year, and over the next 10 million years it will travel about 1,500 km into Asia. About 20 mm/year of the India-Asia convergence is absorbed by thrusting along the Himalaya southern front. This leads to the Himalayas rising by about 5 mm/year, making them geologically active. The movement of the Indian plate into the Asian plate also makes this region seismically active, leading to earthquakes from time to time. Glaciers and river systemsImage:Himalayan mountains from air 001.jpg Glaciers near by K2. The Himalayan range encompasses a very large number of glaciers, notable among which is the Siachen Glacier, the largest 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: Image:Glacial lakes, Bhutan.jpg This image shows the termini of the glaciers in the Bhutan-Himalaya. Glacial lakes have been forming rapidly on the surface of the debris-covered glaciers in this region during the last few decades.
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, the 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.[2] 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 won't be known for many years it potentially could mean disaster for the hundreds of thousands of people that rely on the glaciers to feed the rivers of northern India during the dry seasons. LakesImage:Pangong lake by martinl.jpg Pangong Tso the largest Himalayan lake located at an altitude of 4,600 meters. Image:Gdm.jpg Gurudogmar, India, a high Himalayan lake at an altitude of 5,148 meters. The Himalaya region is dotted with hundreds of lakes. Most lakes are found at altitudes of less than 5,000 m, with the size of the lakes diminishing with altitude. The largest lake is the Pangong Tso, which is spread across the border between India and Tibet. It is situated at an altitude of 4,600 m, and is 8 km wide and nearly 134 km long. A notable high (but not the highest) lake is the Gurudogmar in North Sikkim at an altitude of 5,148 m (16,890 feet) (altitude source: SRTM). Other major lakes include the Tsongmo lake, near the Indo-China border in Sikkim and Tilicho lake, a large lake in an area that was closed to outsiders until recently. The mountain lakes are known to geographers as tarns if they are caused by glacial activity. Tarns are found mostly in the upper reaches of the Himalaya, above 5,500 metres. For more information about these, see here. Impact on climateThe Himalayas have a profound effect on the climate of the Indian subcontinent and the Tibetan plateau. It prevents frigid, dry Arctic winds from blowing south into the subcontinent, which keeps South Asia much warmer than corresponding temperate regions in the other continents. It also forms a barrier for the monsoon winds, keeping them from traveling northwards, and causing heavy rainfall in the Terai region. The Himalayas are also believed to play an important part in the formation of Central Asian deserts such as the Taklamakan and Gobi deserts. The mountain ranges also prevent western winter disturbances from Iran from traveling further, resulting in snow in Kashmir and rainfall for parts of Punjab and northern India. Despite being a barrier to the cold northernly winter winds, the Brahmaputra valley receives part of the frigid winds, thus lowering the temperature in the northeast Indian states and Bangladesh. These winds also cause the North East monsoon during this season for these parts. In turn, the weather phenomenon called Jet Stream affects our image of the highest peaks on earth. The strong stream of winds from the west pass through Everest, creating a familiar plume of snows blowing from the summit, and visible from a great distance. Mountain passesThe rugged terrain of the Himalaya makes few routes through the mountains possible. Some of these routes include:
Impact on politics and cultureImage:Yumthanghimalayas.jpg Mountain sheds like these are used by the rural populace as shelter for cattle in summer months as they take them for grazing in higher altitudes. The Himalayas, due to their large size and expanse, have been a natural barrier to the movement of people for tens of thousands of years. In particular, this has prevented intermingling of people from the Indian subcontinent with people from China and Mongolia, causing significantly different languages and customs between these regions. The Himalayas have also hindered trade routes and prevented military expeditions across its expanse. For instance, Genghis Khan could not expand his empire south of the Himalayas into the subcontinent. HimalHimal is Nepalese for "mountain" and is used to name the various mountains of the Himalayas. In Nepal, these are as follows:
Notable peaks
Notable Himalayan Mountaineers
Religion and mythologyImage:Vaishno.jpg The Vaishno Devi shrine near Jammu, India Several places in the Himalaya are of religious significance in Hinduism and Buddhism. In Hinduism, the Himalaya have also been personified as the god Himavat, the father of Shiva's consort, Parvati.
The Himalayas in fictionImage:Tintin Cover - Tintin in Tibet.JPG The cover of Tintin in Tibet
See also
Notes
Further reading
References
The Himalayan Journal published by Himalayan Club
|
Sites |
Searched sites for "Himalayas" |
|
No sites found. |
Sorry, no matching site records were found. |
Want your site listed here?
|
||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
|
Submit
your site |
|
Relevant quality search results and fast easy navigation throughout the
different sections of the site, make Americola.com |