Himalayas

The Himalayas, or Himalaya, is a mountain range in Asia. It separates the plains of the Indian subcontinent from the Tibetan Plateau. The range has some of the highest peaks on Earth, including the tallest, Mount Everest. More than 100 peaks rise above elevations of 7,200 metres (23,600 feet) above sea level.

The Himalayas stretch across five countries: Nepal, India, China, Bhutan, and Pakistan. The area of the range in the Kashmir region is disputed by India, Pakistan, and China. The Karakoram and Hindu Kush ranges lie to the northwest. The Tibetan Plateau is to the north, and the Indo-Gangetic Plain is to the south. Some of the world's big rivers begin near the Himalayas. These include the Indus, the Ganges, and the Tsangpo–Brahmaputra. The land drained by these rivers is home to about 600 million people. About 53 million people live in the Himalayas themselves.

The Himalayas have shaped the cultures of South Asia and Tibet. Many Himalayan peaks are holy in Hinduism and Buddhism. Several peaks have summits that climbers are not allowed to reach. These include Kangchenjunga (from the Indian side), Gangkhar Puensum, Machapuchare, and Nanda Devi. Kailash is also on this list. It is in the Tibetan Transhimalaya, which has different rocks but is close by.

The Himalayas were uplifted when the Indian tectonic plate crashed into the Eurasian plate. The top layer of Indian crust folded and formed sheets of rock. A lower layer kept pushing into Tibet and made its plateau thicker. The deepest layers of rock sank under Eurasia. The range runs from west-northwest to east-southeast in a curve about 2,400 km (1,500 mi) long. Its western anchor, Nanga Parbat, lies just south of a big bend in the Indus River. Its eastern anchor, Namcha Barwa, lies just west of a great bend in the Yarlung Tsangpo River. The Indus-Yarlung suture zone separates the Himalayas from the Tibetan plateau. The range is 350 kilometres (220 miles) wide in the west and 151 km (94 mi) wide in the east.

If you are looking for other uses of the name, see Himalaya (disambiguation).

Etymology

The name of the range comes from the Sanskrit word Himālaya, which means "abode of snow." It is made from hima ("frost" or "cold") and ālaya ("dwelling" or "house"). Similar names are used in many languages, including Nepali, Hindi, Garhwali, Kumaoni, Tibetan, Sinhala, Urdu, Bengali, and Chinese.

The name was also once written as Himmaleh. It appears in the poems of Emily Dickinson and the essays of Henry David Thoreau. In older writings, including the long Sanskrit story Mahabharata, the range is sometimes called "Himivan." Himavat is a Hindu god who stands for the Himalayan mountains. Other names mean "king of snow," "land of snow," and "lord of mountains."

See also: List of Himalayan peaks and passes and Himalayan Rim

The Himalayas are made of four long, parallel mountain ranges. From south to north, they are the Sivalik Hills, the Lower Himalayan Range, the Great Himalayas in the middle, which is the highest, and the Tibetan Himalayas. The Karakoram are usually counted as separate. In the middle of the range, Dhaulagiri and Annapurna in Nepal are both over 8,000 metres tall. Further east, the Mahalangur Himal holds four of the world's six highest mountains, including Everest, the highest. The Kangchenjunga massif, on the border with India, is the third-highest mountain in the world.

The Himalayas stretch from the Nanga Parbat peak in the west to Namche Barwa in the east. There, the Brahmaputra River bends around the mountain and forms the world's deepest canyon. Many sacred places are found here, such as Mount Kailash, which is respected by several religions. The range passes through countries and regions including Sikkim, Bhutan, Uttarakhand, Himachal Pradesh, Jammu and Kashmir, Ladakh, and parts of Pakistan.

Main article: Geology of the Himalayas

The Himalayas formed through plate tectonics, the slow movement of large pieces of the Earth's outer shell. The crust sits on top of the mantle, and tectonic plates are carried along by slow currents in the asthenosphere. About 70 million years ago, India began to split away from Gondwana and move north with the Indian continental plate and the Neo-Tethys oceanic plate. The lighter oceanic plate subducted, or slid under Eurasia, but the Indian plate was too thick and light to sink. Its rock was pushed into nappes, or stacked sheets, which built up the mountains. As the geophysicist Peter Molnar said, most of the Himalayas are "slices of rock that once were the top part of India's crust."

The Tibetan Plateau formed as the crust was squeezed and thickened when India pushed into Eurasia. The Indus River and the Yarlung Tsangpo, which later becomes the Brahmaputra, flow along the Indus-Yarlung suture zone north of the mountains. The Indian plate still moves north at about 67 mm (2.6 in) per year, so the Himalayas keep rising by about 5 mm each year. This makes the region seismically active, which means earthquakes happen there from time to time.

Hydrology

Confluence of the Indus and Zanskar rivers in Ladakh

Imja Khola river valley in Solukhumbu, Nepal

The Himalayas are very big, but they do not form a major continental divide. Many rivers cut through the range, especially in the east. Because of this, the main ridge is not clearly marked, and mountain passes are less useful for crossing the range than in other mountain ranges. The rivers on the west side form the Indus Basin. The Indus starts in Tibet, flows through India and Pakistan, and then reaches the Arabian Sea. Its main tributaries include the Jhelum, Chenab, Ravi, Beas, and Sutlej rivers. These are the five rivers of the Punjab. The other rivers form the Ganges-Brahmaputra Basin. Its main rivers are the Ganges, the Brahmaputra, and the Yamuna. The Brahmaputra starts as the Yarlung Tsangpo River in western Tibet, flows through Assam, and joins the Ganges in Bangladesh. Together they flow into the Bay of Bengal through the world's largest river delta, the Sunderbans. Rivers from the northern slopes of Gyala Peri flow into the Irrawaddy River, which runs through Myanmar to the Andaman Sea. The Salween, Mekong, Yangtze, and Yellow River come from parts of the Tibetan Plateau that are not truly Himalayan. Some geologists still call all these rivers the circum-Himalayan rivers.

Glaciers

The great ranges of central Asia, including the Himalayas, hold the third-largest amount of ice and snow in the world, after Antarctica and the Arctic. Some people call this region the "Third Pole." About 15,000 glaciers in the range store roughly 12,000 cubic kilometres (2,900 cubic miles), or 3600–4400 Gt (10¹² kg), of fresh water. Famous glaciers include the Gangotri and Yamunotri in Uttarakhand, the Khumbu glacier near Mount Everest, the Langtang glacier, and the Zemu in Sikkim. The mountains are near the Tropic of Cancer, so the permanent snow line is among the highest in the world, around 5,500 m (18,000 ft). Scientists have noticed glaciers melting faster in recent years because of climate change. A large share of glacier water flows into rivers during dry seasons. Studies have measured an overall loss of about 13% of glacier cover over the last 40–50 years.

Lakes

See also: List of Alpine lakes in India

The Himalayan region has hundreds of lakes. Pangong Tso, on the border between India and China, is one of the largest, with a surface area of 700 km² (270 sq mi). South of the main range, lakes are smaller, such as Tilicho Lake in Nepal, one of the highest lakes in the world. Other lakes include Rara Lake, She-Phoksundo Lake in the Shey Phoksundo National Park, Gurudongmar Lake in North Sikkim, the Gokyo Lakes in Solukhumbu district of Nepal, and Lake Tsongmo. Some lakes can cause a glacial lake outburst flood. The Tsho Rolpa glacier lake in the Rowaling Valley, in the Dolakha District of Nepal, is considered the most dangerous. It has grown a lot over the last 50 years as the glacier melts. Mountain lakes formed by glacier activity are called tarns. They are mostly found above 5,500 m (18,000 ft). Many lower lakes, such as Khecheopalri in the Sikkim Eastern Himalayas, have not been well studied.

Climate

The climate of the Himalayas depends on latitude, altitude, and the Southwest monsoon. The mountains stretch over more than eight degrees of latitude. Their high peaks block cold air from Central Asia, so the tropical zone reaches farther north here than anywhere else in the world. Warm air from the Bay of Bengal rises past Namcha Barwa into southeastern Tibet. The temperature drops by 2.0 degrees C (3.6 degrees F) for every 300 metres (980 ft) you climb. Sunny slopes get more heat. The mountain's matter can act like a heat island, which takes in heat and holds it, and this affects the heat budget. Because the peaks are so big, many of them have their own weather.

The monsoon winds, linked to the Southwest Monsoon, bring most of the rain. Warm, wet air from the Indian Ocean is pushed toward land. When it meets the mountains, it rises, cools, and falls as heavy rain. This lifting is called the orographic effect. Winter winds from Central Asia are dry. The western disturbance brings winter rain, mostly in the west. Heavy monsoon rain falls from June to September, which can cause landslides and make travel hard.

The Himalayas have many different climates. The lower areas, including the Pokhara Valley and the Kathmandu valley, are humid subtropical, according to the Köppen climate classification and the Humid subtropical climate. Higher areas have a subtropical highland climate. It rains much more in Darjeeling in the east than in the west, but local differences often matter more. On the dry north side, the cold desert climate of Upper Mustang gets little rain. It is sheltered by the Annapurna massif and Dhaulagiri. The south side of those mountains gets much more rain. Higher up, the land becomes tundra, with snow and ice all year.

The Himalayas shape the climate of the Indian subcontinent and the Tibetan Plateau. They keep South Asia warmer than temperate regions on other continents. They also cause heavy rain in the Terai. Their rain shadowing may help form the deserts of Taklamakan and Gobi.

Ecology

Main article: Ecology of the Himalayas

The plants and animals of the Himalayas change with the climate, rainfall, height, and soil. The climate goes from warm at the bottom of the mountains to ice and snow at the very top. Along the southern side of the range, it gets rainier from west to east. Because of this mix of height, rain, and soil, many different plants and animals can live here. The thin air and deep cold high up suit extremophile organisms, which are living things that can survive harsh conditions. High on the mountains, the rare and endangered snow leopard is the main predator. It hunts goats that live on rocky land and eat grass on mountain pastures. One of these goats is the bharal, also called the Himalayan blue sheep, which is found only in this region. The Himalayan musk deer also lives at high altitudes. People hunted it for its musk, so it is now rare and endangered. Other plant-eating animals that live mostly here include the Himalayan tahr, the takin, the Himalayan serow, and the Himalayan goral. The Himalayan form of the brown bear is very endangered. It is found in scattered places across the range, and so is the Asian black bear. In the mixed forests of the eastern Himalayas, red pandas eat bamboo growing thickly under the trees. Lower down, the forests at the foot of the mountains are home to several kinds of monkeys. These include the endangered Gee's golden langur and the Kashmir gray langur, which live in very small areas in the east and west of the Himalayas.

Religions

Many religions and legends are connected to the Himalayas. The Taktsang Monastery is in the upper Paro valley of Bhutan. It is built into a cliffside, around a cave where Guru Padmasambhava is believed to have meditated. A Shiva shrine stands on the shore of the Gangabal glacial lake, below Harmukh, a sacred mountain for Hindus north of the Kashmir Valley. In Jainism, Mount Ashtapada is a sacred place. The first Jain tirthankara, Rishabhanatha, reached moksha there. After he reached nirvana, his son, Bharata, built three stupas and twenty-four shrines there for the 24 _tirthankara_s. For Hindus, the Himalayas are personified as Himavat, the king of all mountains and the father of the goddess Parvati. Two of the most sacred pilgrimage places for Hindus are the temple complex at Pashupatinath and Muktinath, also known as Shaligrama. It gets this name from the sacred black rocks called shaligrams.

The Buddhists also value the Himalayas greatly. Paro Taktsang is a holy place where Buddhism began in Bhutan. Padmasambhava is said to have started Buddhism there. Several places in the Himalayas are important to Sikhism, Islam and Hinduism as well. Many Vajrayana Buddhist sites are found in Tibet, Bhutan, and the Indian regions of Ladakh, Sikkim, Arunachal Pradesh, Spiti, and Darjeeling. There were more than 6,000 monasteries in Tibet, including the residence of the Dalai Lama. Bhutan, Sikkim, and Ladakh are also home to many monasteries.

Resources

The Himalayas are home to many medicinal plants. People have used plants from the forests for thousands of years to treat everything from simple coughs to snake bites. Different parts of a plant, such as the root, flower, stem, leaves, or bark, are used to treat different problems. For example, bark from an Abies pindrow tree is used to treat coughs and bronchitis. A paste made from the leaves and stem of an Andrachne cordifolia is used on wounds and as a remedy for snake bites. The bark of a Callicarpa arborea is used for skin problems. Nearly a fifth of the gymnosperms, angiosperms, and pteridophytes in the Himalayas have been found to have medicinal properties, and scientists expect to find more.

In some countries in Asia and Africa, most people rely on medicinal plants instead of medicine from a pharmacy. In the Himalayas, many people use these plants as their only way to heal, so the plants are an important source of income. This helps economic and industrial development both inside and outside the region. However, local people are quickly clearing the forests for wood, and often do so illegally.