The Himalayas, or Himalaya, is a mountain range in Asia separating the plains of the Indian subcontinent from the Tibetan Plateau. The range has some of the highest peaks on Earth, including the highest, Mount Everest. More than 100 peaks exceeding elevations of above sea level lie in the Himalayas.
The Himalayas span five countries: Nepal, India, China, Bhutan, and Pakistan. The sovereignty of the range in the Kashmir region is disputed among India, Pakistan, and China. The Himalayan range is bordered on the northwest by the Karakoram and Hindu Kush ranges, on the north by the Tibetan Plateau, and on the south by the Indo-Gangetic Plain. Some of the world's major rivers, the Indus, the Ganges, and the Tsangpo–Brahmaputra, rise in the vicinity of the Himalayas, and their combined drainage basin is home to some 600 million people; 53 million people live in the Himalayas. The Himalayas have profoundly shaped the cultures of South Asia and Tibet. Many Himalayan peaks are sacred in Hinduism and Buddhism. The summits of several are off-limits to climbers. These include Kangchenjunga (from the Indian side), Gangkhar Puensum, Machapuchare, and Nanda Devi; and Kailash in the geologically distinct, but nearby Tibetan Transhimalaya.
The Himalayas were uplifted after the collision of the Indian tectonic plate with the Eurasian plate, specifically, by the folding, or nappe-formation of the uppermost Indian crust, even as a lower layer continued to push on into Tibet and add thickness to its plateau; the still lower crust, along with the mantle, however, subducted under Eurasia. The Himalayan mountain range runs west-northwest to east-southeast in an arc long. Its western anchor, Nanga Parbat, lies just south of the northernmost bend of the Indus River. Its eastern anchor, Namcha Barwa, lies immediately west of the great bend of the Yarlung Tsangpo River. The Indus-Yarlung suture zone, along which the headwaters of these two rivers flow, separates the Himalayas from the Tibetan plateau; the rivers also separate the Himalayas from the Karakorams, the Hindu Kush, and the Transhimalaya. The range varies in width from in the west to in the east.
Etymology The name of the range hails from the Sanskrit ( 'abode of snow'), from ( 'frost/cold') and ( 'dwelling/house'). The cognates include:
in Nepali and Hindi, हिंवाळ Hinvāl in Garhwali, हिमाल Himāl in Kumaoni, Himalaya in Tibetan, in Sinhala, Himāliya in Urdu, Himaloẏ in Bengali, or Xǐmǎlāyǎ in Chinese.
This name was also previously transcribed as Himmaleh, as in Emily Dickinson's poetry. and Henry David Thoreau's essays..
The name of the range is sometimes also given as "Himivan" in older writings, including the Sanskrit epic Mahabharata. Entry: "Himavan" Himavat (Sanskrit: हिमवत्) or Himavān (Sanskrit: हिमवान्) is a Hindu deity who is the personification of the Himalayan Mountain Range. Other epithets include Sanskrit: हिमराज Himaraja (), Tibetan: (lit. 'land of snow'), or Sanskrit: पर्वतेश्वर Parvateshwara ().
Geography and key features
The Himalayas consists of four parallel mountain ranges from south to north: the Sivalik Hills on the south; the Lower Himalayan Range; the Great Himalayas, which is the highest and central range; and the Tibetan Himalayas on the north. The Karakoram are generally considered separate from the Himalayas.
In the middle of the great curve of the Himalayan mountains lie the peaks of Dhaulagiri and Annapurna in Nepal, separated by the Kali Gandaki Gorge. The gorge splits the Himalayas into Western and Eastern sections, both ecologically and orographically – the pass at the head of the Kali Gandaki, the Kora La, is the lowest point on the ridgeline between Everest and K2 (the highest peak of the Karakoram range). To the east of Annapurna are the peaks of Manaslu and across the border in Tibet, Shishapangma. To the south of these lies Kathmandu, the capital of Nepal and the largest city in the Himalayas. East of the Kathmandu Valley lies the valley of the Bhote/Sun Kosi river which rises in Tibet and provides the main overland route between Nepal and China – the Araniko Highway/China National Highway 318. Further east is the Mahalangur Himal with four of the world's six highest mountains, including the highest: Cho Oyu, Everest, Lhotse, and Makalu. The Khumbu region, popular for trekking, is found here on the south-western approaches to Everest. The Arun river drains the northern slopes of these mountains, before turning south and flowing to the range to the east of Makalu.
In the far east of Nepal, the Himalayas rise to the Kangchenjunga massif on the border with India, the third-highest mountain in the world, the most easterly summit and the highest point of India. The eastern side of Kangchenjunga is in the Indian state of Sikkim. Formerly an independent Kingdom, it lies on the main route from India to Lhasa, Tibet, which passes over the Nathu La pass into Tibet. East of Sikkim lies the ancient Buddhist Kingdom of Bhutan. The highest mountain in Bhutan is Gangkhar Puensum, which is also a strong candidate for the highest unclimbed mountain in the world. The Himalayas here are becoming increasingly rugged, with heavily forested steep valleys. The Himalayas continue, turning slightly northeast, through the Indian State of Arunachal Pradesh as well as Tibet, before reaching their easterly conclusion in the peak of Namche Barwa, situated in Tibet, inside the great bend of the Yarlang Tsangpo river. On the other side of the Tsangpo, to the east, are the Kangri Garpo mountains. The high mountains to the north of the Tsangpo, including Gyala Peri, however, are also sometimes included in the Himalayas.
Going west from Dhaulagiri, Western Nepal is somewhat remote and lacks major high mountains, but is home to Rara Lake, the largest lake in Nepal. The Karnali River rises in Tibet but cuts through the centre of the region. Further west, the border with India follows the Sarda River and provides a trade route into China, where on the Tibetan plateau lies the high peak of Gurla Mandhata. Just across Lake Manasarovar from this lies the sacred Mount Kailash in the Kailash Ranges, which stands close to the source of the four main rivers of Himalayas and is revered in Hinduism, Jainism, Buddhism, Sufism and Bonpo. In Uttarakhand, the Himalayas are regionally divided into the Kumaon and Garhwal Himalayas with the high peaks of Nanda Devi and Kamet. The state is also home to the important pilgrimage destinations of Chota Chaar Dhaam, with Gangotri, the source of the holy river Ganges, Yamunotri, the source of the river Yamuna, and the temples at Badrinath and Kedarnath.
The next Himalayan Indian state, Himachal Pradesh, is noted for its hill stations, particularly Shimla, the summer capital of the British Raj, and Dharamsala, the centre of the Tibetan community and government in exile in India. This area marks the start of the Punjab Himalaya and the Sutlej river, the most easterly of the five tributaries of the Indus, cuts through the range here. Further west, the Himalayas form much of the disputed Indian-administered union territory of Jammu and Kashmir where lie the mountainous Jammu region and the renowned Kashmir Valley with the town and lakes of Srinagar. The Himalayas form most of the south-west portion of the disputed Indian-administered union territory of Ladakh. The twin peaks of Nun Kun are the only mountains over in this part of the Himalayas. Finally, the Himalayas reach their western end in the dramatic 8000-metre peak of Nanga Parbat, which rises over above the Indus valley and is the most westerly of the 8000-metre summits. The western end terminates at a magnificent point near Nanga Parbat where the Himalayas intersect with the Karakoram and Hindu Kush ranges, in the disputed Pakistani-administered territory of Gilgit-Baltistan. Some portion of the Himalayas, such as the Kaghan Valley, Margalla Hills, and Galyat tract, extend into the Pakistani provinces of Khyber Pakhtunkhwa and Punjab.
Geology
Tectonics, the recurring physical changes that affect the arrangement of the Earth's crust, and plate tectonics, the movement of large regions of the Earth's crust in the manner of planar rigid bodies, are key to understanding the formation of the Himalayas. The Earth's crust rests directly on its mantle. Tectonic plates, comprising the crust and the upper portions of their underlying mantle, are moved around by convection in the asthenosphere. The oceanic crust, found beneath oceans, is, on average, thick. It is created from upwelling magma at mid-ocean ridges and predominantly consists of basalt, the principal igneous rock on Earth. In contrast, the continental crust underlying dry land has an average thickness of and is rich in silica, which is less dense than basalt. It makes the continental tectonic plates more buoyant than the oceanic.
India's defining geologic processes, which began 70 million years ago, had involved India rifting, or splitting away, from Gondwana, and the Indian continental plate along with the Neo-Tethys oceanic plate above it jointly moving northward. As these eventually reached the Eurasian plate, the less buoyant oceanic plate subducted, or slid under Eurasia and was carried into the deeper asthenosphere. In contrast, the Indian continental plate was obstructed because of its thickness and buoyancy. The lateral compression generated by the obstruction caused the plate to be sheared horizontally. Its lower crust and mantle slid under, but one layer of the upper crust piled up in sheets (called nappes) ahead of the subduction zone. Geophysicist Peter Molnar noted that most of the Himalayas are "slices of rock that once were the top part of India's crust." This is the process of mountain building, or orogeny, in the Himalayas.
Before the orogeny, the Eurasian coastline had been similar to today's Central Andes. Along such coastlines, the adjoining oceanic plate subducts and erupts as volcanoes. Magma, which eventually crystallizes into granite, rises into the Earth's crust below the active volcanoes but not to the surface. When India's continental plate pushed against Eurasia, not only did a part of the upper crust fold in nappes, but another stiffer part began to push against (or drag) Eurasia's ancient volcanic mountains farther north. As a result, the crust of this formerly coastal region shortened under compression and thickened to become what is today the Tibetan Plateau. Isostatic equilibrium, or the balance between the gravitational force pulling down on the crust and the force of buoyancy pushing up from the mantle, gives the Tibetan Plateau its notable thickness and altitude.
The Indian plate was not the only landmass that had rifted from Gondwana and drifted northward toward Eurasia. Before the India-Eurasia collision in Middle Paleocene (60 Mya) and subsequent Himalayan orogeny, two other landmasses, the Qiangtang terrane and Lhasa terrane, had drifted up from Gondwana. Qiangtang, a geological region in what is today northern Tibet, had done so in Late Triassic (237–201 Mya). The Lhasa terrane collided with the southern boundary of the Qiangtang in the Early Cretaceous (145–100 Mya). The collision caused the lithospheric mantle of the Lhasa terrane to thicken and shorten, forming a barrier that later prevented the Indian lithosphere from fully subducting under Tibet and leading to further thickening of the Tibetan plateau. The suture zones, or remains of the subduction zone and the terranes that are joined, are found in the Tibetan plateau. The Qiantang and Lhasa terranes were part of the string of microcontinents Cimmeria, today constituting parts of Turkey, Iran, Pakistan, China, Myanmar, Thailand and Malaysia, which had rifted from Gondwana earlier, closing the Paleo-Tethys Ocean above them and opening the Neo-Tethys Ocean between them and Gondwana, eventually colliding with Eurasia, and creating the Cimmerian Orogeny.