Himalayan System

Notes

The Himalaya are young fold mountains about 2,400 km long, formed by the collision of the Indian and Eurasian plates. They are about 400 km wide in Kashmir and 150 km wide in Arunachal Pradesh.

Longitudinal divisions

Trans-Himalaya (Tibetan Himalaya): north of the Great Himalaya; Karakoram, Ladakh and Zanskar ranges. K2 (Godwin-Austen), the second highest peak in the world (8,611 m), is in the Karakoram; the Siachen glacier is here.
Greater Himalaya (Himadri): an average height above 6,000 m; contains the highest peaks: Everest, Kanchenjunga, Makalu, Dhaulagiri, Annapurna, Nanga Parbat, Nanda Devi (7,816 m, the highest peak wholly within India).
Lesser Himalaya (Himachal): 3,700-4,500 m; Pir Panjal, Dhauladhar, Mussoorie, Mahabharat ranges; hill stations (Shimla, Mussoorie, Nainital, Darjeeling); valleys (Kashmir, Kangra, Kullu).
Shiwaliks (Outer Himalaya): 900-1,100 m; foothills of gravel and alluvium; the longitudinal valleys here are called duns (Dehradun) in the west and duars in the east.
Purvanchal (Eastern hills): Patkai, Naga, Manipur and Mizo (Lushai) hills.

Regional divisions: Punjab Himalaya (Indus-Sutlej), Kumaon Himalaya (Sutlej-Kali), Nepal Himalaya (Kali-Tista), Assam Himalaya (Tista-Dihang).

Important passes

Jammu and Kashmir/Ladakh: Banihal, Zoji La (Srinagar-Leh), Khardung La, Karakoram Pass.
Himachal Pradesh: Rohtang La, Shipki La (on the Sutlej, to Tibet).
Uttarakhand: Lipulekh, Mana, Niti.
Sikkim: Nathu La and Jelep La. Arunachal Pradesh: Bomdi La.

Thrusts (geology): the Main Central Thrust, Main Boundary Thrust and Himalayan Frontal Thrust are active, so the region is earthquake-prone.

Significance: a climatic barrier (stops cold Central Asian winds and brings monsoon rain), the source of perennial rivers, rich biodiversity, glaciers, hydropower, forests, minerals, tourism and defence.

Key Points

Divisions: Trans-Himalaya, Himadri, Himachal, Shiwaliks, Purvanchal.
Himadri has the highest peaks; Nanda Devi is the highest wholly in India.
Duns lie between the Lesser Himalaya and the Shiwaliks.
Key passes: Zoji La, Banihal, Rohtang, Shipki La, Nathu La.
Active thrusts make the region seismically sensitive.

MCQs

Q1. The highest peak wholly within India is:
(a) Kanchenjunga
(b) Nanda Devi
(c) K2
(d) Nanga Parbat Ans:
(b). Kanchenjunga lies on the India-Nepal border.

Q2. Zoji La pass connects:
(a) Srinagar and Leh
(b) Manali and Leh
(c) Shimla and Kinnaur
(d) Gangtok and Lhasa Ans:
(a).

Q3. The outermost range of the Himalaya is the:
(a) Himadri
(b) Himachal
(c) Shiwalik
(d) Karakoram Ans:
(c).