The Himalayas: how they formed and their three ranges

A wall of snow

On a physical map, the Himalayas look like a long, high wall across the north of India, about 2,500 km from end to end. Their name joins two Sanskrit words, hima (snow) and alaya (dwelling), so it means ‘abode of snow’. Many peaks rise above 8,000 m and are called the Eight Thousanders. The range crosses six countries: Afghanistan, Pakistan, India, China, Nepal and Bhutan.

How the Himalayas were formed

Long ago, India was part of a huge landmass called Gondwana, with Africa as its neighbour. It broke away and drifted slowly north over millions of years. About 50 million years ago it reached Eurasia and crashed into it. As India kept pushing, the land between them crumpled and rose, just as a carpet wrinkles when you push it against a wall. Bent and folded layers of rock in the mountains show this story clearly.

The push has not stopped. India still moves into Asia about 5 cm a year, slower than your hair grows. So the Himalayas are still rising, by about 5 mm a year. That sounds tiny, but in a thousand years it adds up to 5 m.

The three ranges

The Himalayas are grouped into three ranges, from north to south:

• The Himadri, or Greater Himalayas, form the tallest, roughest part, with peaks such as Mount Everest and Kanchenjunga. Snow covers them all year, life is hard and there are few settlements.
• The Himachal, or Lower Himalayas, lie to the south and have a milder climate, so plants, animals and people thrive. Hill stations such as Shimla, Nainital, Mussoorie and Darjeeling are here.
• The Shivalik Hills, or Outer Himalayas, are the lowest range: rolling, forested foothills full of wildlife that lead down to the Gangetic Plains.

The Water Tower of Asia

In summer the snow and glaciers melt and feed great rivers: the Ganga, the Indus and the Brahmaputra. With their tributaries, they give water for drinking, farming and industry to hundreds of millions of people, which is why the Himalayas are called the Water Tower of Asia. The Bhagirathi, a main stream of the Ganga, begins at Gaumukh, ‘the cow’s mouth’, at the edge of the Gangotri Glacier in Uttarakhand, a place visited by pilgrims and trekkers.

Living in the mountains

People have adapted to the mountains in clever ways. In the western Himalayas, kath-kuni houses, also called dhajji-dewari, are built of local stone and wood that keep the home warm and help it withstand mild earthquakes. In Ladakh, yaks give milk, meat, wool and dung, and carry loads. The mountains are also sacred to many people, and temples and monasteries stand among the peaks. Himachal Pradesh’s Great Himalayan National Park, a UNESCO World Heritage Site, protects the Himalayan monal, the snow leopard and many other species, with help from the villages inside it.

Why it matters

The Himalayas give India water, shape its weather and form a natural wall in the north. See how they fit with the rest of the land in physical features of India, follow the rivers to the sea in coastlines and islands, and find every textbook answer in the NCERT solutions for Chapter 1; see all of the Chapter 1 notes.