Himalayan Mountains: Extent, Formation, Passes, Peaks and Classification

The Himalayan mountain system is the world’s highest, and home to the world’s highest peaks including Mount Everest and K2. This system also includes Karakoram, Hindu Kush and other ranges extending out from the Pamir knot. There are over 100 mountains in Himalaya system whose height exceeds 7,200m. After Himalayan peaks, it is Aconcagua, in the Andes, at 6,962 metres, known to be the highest peak outside Asia.

Himalaya system gives rise to some of world’s major river systems. The combined drainage basin is home to slightly less than half of world’s population. The highest peak Everest is located in Nepal. Another peak K2 is on the border of Pakistan and China. Kanchenjunga is located on the border of Nepal and India. Nanda Devi is the highest peak within India.

Extent of Himalayas

The main Himalayan ranges run from Indus river valley in the west to the Brahmaputra river valley in east forming a 2,400 km long arc. The width of this arc is around 400 kilometer in Western Kashmir while 150 kilometers in Arunachal Pradesh-Tibet region.

Himalayan Orogeny

Geologically, the origin of the Himalayas is the impact of the Indian tectonic plate travelling northward at 15 cm per year to impact the Eurasian continent, about 40-50 million years ago. The formation of the Himalayan arc resulted since the lighter rock of the seabeds of that time was easily uplifted into mountains. The evidence for this is that the summit of Mount Everest is made of marine limestone. Due to recent origin on geological time scale, Himalayan mountains are called Young Fold Mountains.  These young fold mountains consist of a series of parallel ranges with deep valleys between them and have variety of rock structures, deep gorges and high pyramidal peaks. In High Himalayas the rivers have steep gradients, which result from the differential uplift of the High Himalayas. It has been suggested that a long and narrow arc of High Himalayas has been uplifted during quaternary.

Important Mountain passes in Himalayas

The rugged terrain makes few routes through the mountains possible. Some of these routes include:

• Banihal is an important pass connecting the hill areas of Jammu to the Kashmir Valley. The Jawahar Tunnel (named after Pandit Jawaharlal Nehru), inaugurated in December 1956, was constructed for round-the-year surface transport
• Zoji La lies between the valley of Kashmir and the Kargil district, and is the only Western entrance to the highlands of Ladakh.
• Rohtang Pass in Himachal Pradesh, India.
• Mohan Pass is the principal pass in the Shiwalik Hills, the southernmost and geologically youngest foothills running parallel to the main Himalayas in Sikkim.
• Kora La at 4,594 meters elevation on the Nepal-Tibet border at the upper end of Mustang. The Kali Gandaki Gorge transects the main Himalaya and Transhimalayan ranges. Kora La is the lowest pass through both ranges between K2 and Everest, but some 300 metres higher than Nathula and Jelepla passes further east between Sikkim and Tibet.
• Aghill Pass: Situated to the north of K2 in the Karakoram at an elevation of 5000 meters, joins Ladakh with the Xinjiang Province of China.
• Bara-Lacha: Bara-lacha la also known as Bara-lacha Pass is located in the Zanskar range connecting Lahaul district in Himachal Pradesh to Ladakh in Jammu and Kashmir, situated along the Leh-Manali highway.
• Bomdi-La: It connects Arunachal Pradesh with Lhasa, the capital of Tibet.
• Chang-La: The Changla Pass or Chang La Pass (el. 5,360 m is located in Ladakh, India. It is the third highest motorable road in the world.
• Debsa Pass: Debsa Pass is a 5,360-metre (17,590 ft) high mountain pass in the Himalaya mountains between the Kullu and Spiti Districts of Himachal Pradesh.
• Dihang-Debang: Situated in the state of Arunachal Pradesh at an elevation of about 4000 feet this pass connects Arunachal Pradesh with Mandalay (Myanmar). The Dihang-Debang Biosphere reserve is located around this area.

Important Peaks of Himalayas

Classification of the Himalaya System

The classification of the Himalayan Ranges is done on three bases viz. Geographical, Regional and Geological.