The Himalaya Range or Himalayas for short, meaning “abode of snow” in Sanskrit, is a mountain range in Asia, separating the Indian subcontinent from theTibetan Plateau. 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.

The Himalayan mountain system is the planet’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 m (22,841 ft), is the highest peak outside Asia, whereas the Himalayan system includes over 100 mountains exceeding 7,200 metres (23,622 ft).

The Himalayan system, which includes various outlying subranges, stretches across six countries: India, Bhutan, China, Afghanistan, Nepal, and Pakistan. Some of the world’s majorrivers, the Brahmaputra, the Ganga, the Indus, Yamuna and the Yangtze, rise in the Himalayas, and their combined drainage basin is home to approximately 1.3 billion people. The Himalayas have profoundly shaped the cultures of South Asia; many Himalayan peaks are sacred in bothHinduism and Buddhism.

The main Himalaya range runs, west to east, from the Indus river valley to the Brahmaputra river valley, forming an arc 2,400 km (1,490 mi) long, which varies in width from 400 km in the western Kashmir-Xinjiang region to 150 km in the eastern Tibet-Arunachal Pradeshregion. The range consists of three coextensive sub-ranges, with the northern-most, and highest, known as the Great or Inner Himalayas.

Ecology

The 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.

Lowland forests

On the Indo-Gangetic plain the base of the mountains, an alluvial plain drained by the Indus and Ganga-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 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 forestsoccupy 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 tallest 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 theHimalayan 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 throughPakistan, India, Nepal and Bhutan. This region consists of many sub-ranges. Summits are generally 600 to 1,200 metres. 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.

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.

Lesser Himalayas

Prominent range 2,000 to 3,000 metres high forming along the Main Boundary Thrust fault zone with a steep southern face and gentler northern slopes. Nearly continuous except for river gorges. Rivers gather in candelabra form to the north to break through this range in relatively few places.

Midlands

‘Hilly’ region averaging about 1,000 metres immediately north of the Mahabharat Range, rising over about 100 km to about 4,000 metres at the Main Frontal Thrust fault zone where the Greater Himalayas begin.

Montane forests – At 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 Grassland

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).

Origins and Growth

The Himalayas are among the youngest mountain ranges on the planet and consist mostly of upliftedsedimentary and metamorphic rock. 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 Plateand the Eurasian Plate. This is referred to as a fold mountain.

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 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 volcanoesthat 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 per year, and over the next 10 million years it will travel about 1,500 km into Asia. About 20 mm per year of the India-Asia convergence is absorbed by thrustingalong the Himalaya southern front. This leads to the Himalayas rising by about 5 mm per 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 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 Gangotriand Yamunotri(Uttarakhand), Nubra, Biafo and Baltoro (Karakoram region), Zemu (Sikkim) and Khumbuglaciers (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, theChenab, the Ravi, the Beas, and the Sutlej rivers, among others.

Most of the other Himalayan rivers drain the Ganga-Brahmaputra Basin. Its two main rivers are the Ganga 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 Ganga 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, 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 thecircum-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 won’t 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.

According to a UN climate report, the Himalayan glaciers that are the sources of Asia’s biggest rivers could disappear by 2035 as temperatures rise and India, Tibet, Pakistan, Bangladesh, Nepal and Myanmar could experience floods followed by droughts in coming decades.

Lakes

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 thePangong Tso, which is spread across the border between India and China. 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 (17,100 ft) (altitude source: SRTM). Other major lakes include the Tsongmo lake, near the Indo-China border in Sikkim, and Tilicho lake in Nepal in the Annapurna massif, a large lake in an area that was closed to tourists 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 meters.

Impact on Climate

The Himalayas have a profound effect on the climate of the Indian subcontinent and the Tibetan plateau. They prevent frigid, dry Arctic winds blowing south into the subcontinent, which keepsSouth 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 Terairegion. The Himalayas are also believed to play an important part in the formation of Central Asiandeserts 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 North East India and Bangladesh.

The Himalayas, which are often called “The Roof of the World”, contain the greatest area of glaciers and permafrost outside of the poles. Ten of Asia’s largest rivers flow from here, and more than a billion people’s livelihoods depend on them. To complicate matters, temperatures are rising more rapidly here than the global average. In Nepal the temperature has risen with 0.6 degree over the last decade, whereas the global warming has been around 0.7 over the last hundred years.

Impacts on Politics and Culture

It should be noted that almost half of the humans and livestock of India live on one-third of the landscape within 500 km of the Himalayan range.

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.

Religion

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.

Some of the important religious places in the Himalayas are:-

Haridwar, the place where the river Ganga enters the plains.

Badrinath, a temple dedicated to Vishnu.

Kedarnath, where one of the 12 Jyotirlingas is located.

Gaumukh, the source of the Bhagirathi (and hence, by extension, the Ganga), located a few miles above the town of Gangotri.

Deoprayag, where the Alaknanda and Bhagirathi merge to form the Ganga.

Rishikesh, has a temple of Lakshmana.

Mount Kailash, a 6,638 m high peak which is the abode of the Hindu Gods Shiva and Uma and is also venerated by Buddhists. The peak is forbidden to climb, it is so sacred it is circled at its base. Lake Manasarowar lies at the base of Mount Kailash, and is the source of the Brahmaputra.

Amarnath, has a natural Shiva linga of ice which forms for a few weeks each year. Thousands of people visit this cave during these few weeks.

The Vaishno Devi is a popular shrine among Durga devotees.

Sri Hemkund Sahib – Sikh gurudwara where Guru Gobind Singh is claimed to have meditated and achieved enlightenment in a previous incarnation.

In addition, to the above, a number of Tibetan Buddhist sites are situated in the Himalaya, including the residence of the Dalai Lama. There were over 6,000 monasteries in Tibet. TheTibetan Muslims had their own mosques in Lhasa and Shigatse.

The following mystic entities are associated with the Himalayas:

The Yeti is one of the most famous creatures in cryptozoology. It is a large primate-like creature that is supposed to live in the Himalaya. Most mainstream scientists and experts consider current evidence of the Yeti’s existence unpersuasive, and the result of hoaxes, legend or misidentification of mundane creatures.

Shambhala is a mystical city with various legends associated with it, it is one of twenty-four Himalayan hidden realms, or beyul, in Vajrayana Buddhism. While some legends consider it to be a real city where secret Buddhist doctrines are being preserved, other legends believe that the city does not physically exist and can only be reached in the mental realm.

This description of the Himalayas is from Wikipedia.org