Summary

Geography Class 36

A brief discussion of the Previous Class (5:11 PM)

Mapping(5:25 PM)

Sikkim and Meghalaya share a border with only one state.
Sikkim shares a border with West Bengal only. Meghalaya Shares a border with Assam only.
Telangana doesn't share a border with Odisha.
Madhya Pradesh doesn't share a border with Jharkhand.
Yamuna flows through Himachal Pradesh as well.

Physiography of India (7:53 PM)

Subcontinent

Subcontinent is the large landmass i.e. part of the continent but is considered separate from the rest of the continent.
For example, the Indian subcontinent, Alaskan Subcontinent, etc.
Reasons for considering India as a subcontinent.
(a) Geographical reasons
Geographically, the Indian subcontinent has well-defined physical boundaries, such as the Himalayas and the Hindukush in the north, Purvanchal in the east, and the Indian Ocean in the South.
(b) Geological reasons
The countries of the Indian subcontinent share common geological history, such as the formation of the Himalayas, northern plains, etc.
(c) Common climatic conditions
All these countries experience monsoon types of climate.
(d) Political reasons
They share a common political identity i.e. South Asia.
(e) Historical and Cultural reasons
They share a common history, ruled by large empires such as Mauryan, Mughal, etc.
They also share a common culture of language, festivals, etc.

Mountains of India (6:05 PM)

Himalayas

Origin of the Himalayas
(Discussed in the Plate tectonic Class. Please refer to the notes of those classes.)
Different stages in the formation of the Himalayas
The Himalayas were formed in three different phases,
(a) First Stage between 120-70 million years ago
During this stage, great Himalayas were formed.
(b) Second stage between 30-25 million years ago.
This resulted in the formation of the middle Himalayas.
(c) Third stage between 20-2 million years ago
This resulted in the formation of the Shivaliks.
Syntaxial Bending
It refers to a deep knee bent, with the strike of the ridges suddenly turning at right angles.
It is due to the maximum push offered at both ends of the Indian Peninsula during its northward drift.
In the northwest direction, the Aravalis and in the northeast the Assam ranges acted as two extended arms, while the central area sagged giving an arcuate shape.
Evidence to prove that the Himalayas are still rising
(a) Frequent earthquakes
(b) Recent adjustment in the height of Himalayan peaks.
(c) Frequent disturbance in the topographies.
(d) The rivers of the Himalayas, are in the youthful stage over a long time.
(e) Drying up of lakes of Tibet, which shows that the Tibetan plateau is still rising.
(Kindly refer to the diagram drawn by the faculty in the class for understanding the Fracture Zones of the Himalayas)

Regional Division of Himalayas (7:17 PM)

The Himalayas are divided by rivers. This classification is called regional division. The main classifications are:
(a) Kashmir Himalayas
Between the river Sutlej and Indus
(b) Kumaon Himalayas
Between the river Sutlej and Kali
(c) Nepal Himalayas
Between the river Kali and Teesta
(d) Assam Himalayas
Between the river Teesta and Brahmaputra.

Western Himalayas	Eastern Himalayas
It includes Punjab and Kumaon Himalayas.	It includes Sikkim and Arunachal Himalayas.
It is between River Indus and River Kali.	It is between River Teesta and the Brahmaputra.
These are wider.	These are narrower.
Middle Himalayas and Shivaliks are separate.	These have merged in the eastern Himalayas.
These are taller.	These are comparatively shorter.
These rise gradually.	These rise abruptly.
The temperature of the western Himalayas is comparatively higher.	The temperature of the eastern Himalayas is comparatively higher.
Coniferous type of vegetation.	Evergreen and deciduous types of vegetation.
Lower biodiversity.	Higher biodiversity
Lower precipitation.	Higher precipitation.
Snowline at the lower altitude	Snowline at the higher altitude.

Longitudinal Division (7:36 PM)

The Topics for the Next Class: Mountains of India (Continued)