The Himalayas Important Topic For UPSC Mains

The Himalayas Important Topic For UPSC Mains

Indian states involved:

Jammu and Kashmir, Himachal Pradesh, Uttarakhand, Sikkim, Arunachal Pradesh, Nagaland, Manipur, Mizoram, West Bengal

Origin:

1. The Geosynclinal Origin:
2. The disintegration of Pangaea led to the formation of a long Tethys Sea between the Lauratian Sheild of the north and the Gondwana land of the south.
3. This swa was occupying the region of the Himalayas during the Mesozoic Era.
4. At the end of the palaeozoic and beginning of the Mesozoic era, the Tethys almost girdled the whole Earth running from Europe in the west to China in the east.
5. Erodedmaterial from thr two land masses was deposited in the Tethys Sea and assumed considerable thickness due to the sinking nature of the sea bed.
6. During the cretaceous period, the bed of sea started rising which led to the folding of three successive ranges of Himalayas.

1. The Plate Tectonic Origin:
2. This is based in the concept of Sea Floor Spreading.
3. According to this theory, about 70m years ago, there was an extensive geosynclines called Tethys, in place of Himalayas.
4. The Indian plate came very close to the subducting under the Asian plate.
5. This caused lateral compression due to which the sediments of the Tethys were squeezed and folded into three parallet rangesof Himalayas.
6. Since the northward movement of the Indian plate is still continuing, the height if the Himalayan peak is increasing.
7. The Indian plate is moving northward and the centre of rotation is constantly changing.

Classification of Himalayas:

It can be classified as:

1. Longitudinally
2. Regionally

Longitudinal classification of Himalayas:

1. The Trans-Himalayas
2. The Greater Himalayas
3. The Lesser Himalayas
4. The Outer Himalayas

The Trans Himalayas:     

• Average width of the region is 40kms at the eastern and western extreams and 222kms in the central part.
• Region of lofty peaks and vast glaciers.
• Rocks of this region contain the fossils bearing marine sediments which are underlain by Tertiary Granite.

The Greater Himalayas:

• Also known as Himadri/Inner or Central Himalayas.
• 25kms wide with an average height of above 6100m
• Contains almost all the lofty peaks like Mt.Everest, Kanchanjunga, Nanga Parbat etc.
• Few Gaps mainly provided by antecedent rivers.
• Less rainfall
• Being lofty, they have very little forest area.

The Lesser Himalayas:

• Also known as Middle Himalayas
• Width is aboiut 80km with an average height of 1300-4600m.
• Consists of unfossiliferous sediments or metamorphosed crystalline.
• Main rocks are slate, limestone and quartzite.
• This region is subjected to extensive erosion due to heavy rainfall, deforestation and urbanization.

The Outer Himalayas:

• Also known as The Shiwaliks/Sub-Himalayas
• Extends from Jammu and Kashmir to Assam.
• 8kms in east to 45kms in the west.
• Average elevation of about 900-1500m above Sea level.
• Not a continuous range.
• Broader in the west and narrows down in the east.
• Several Doon areas.

Regional/Transverse Classification of Himalayas

1. Western Himalayas
   1. Kashmir Himalayas
   2. Himachal Himalayas
2. Central Himalayas
   1. U.P Himalayas
   2. Nepal Himalayas
3. Eastern Himalayas
   1. Darjeeling-Bhutan-Assam Himalayas
   2. Purvanchal

Passes through the mountain wall:

1. The Khyabar Pass
   1. 1000m
   2. Leadsfrom Peshawar to Kabul.
   3. Most famous of all the passes
2. The Gomal Pass
   1. 1525m
   2. South of Khyber Pass
   3. Served as a trade route passing through Waziristan(Pakistan)
3. The Bolan Pass
   1. 1800m
   2. Between Sulaiman and the Kirthar ranges
   3. Leads from Kandhar to Quetta
4. In the very north, there are two difficult routes via the Karakoram Pass and the Z         ozila Pass where there are roads communicating with Srinagar.
5. The Shipki  Pass
   1. Leads from Punjab to Tibet
6. Bomdila Pass
   1. In Arunachal Pradesh

Significance of Himalayas:

1. Climatic Influence
2. Defense
3. Source of Perennial Rivers
4. Source of fertile soils
5. Generation of Hydroelectricity
6. Forest Wealth/Richness of Flora and Fauna
7. Orchards
8. Minerals
9. Tourism
10. Pilgrimages

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