The Himalayas (India’s Geographical Division)-हिमालय (भारत का भौगोलिक प्रभाग)

The Origin –

The term Himalaya means Him + alaya i.e. snow clad.

The story of their origin began 32 crore yrs back when all the continents were at one place known as Pangea. It was covered by oceans which was known as Panthalsa.

At a place, where currently  Himalaya is situated, a geosynclines which was filled with water  existed  known as Tethyus.

India is entirely contained on the Indian Plate, a major tectonic plate that was formed when it split off from the ancient continent Gondwanaland.

Late in the Triassic Period (which lasted from approximately 251 million to 199.6 million years ago), Pangea fragmented, and the parts began to move away from one another.

About 90 million years ago, during the late Cretaceous Period, the Indian Plate began moving north at about 15 cm/year (6 in/yr). 

About 50 to 55 million years ago, in the Eocene Epoch of the Cenozoic Era, the plate collided with Asia after covering a distance of 2,000 to 3,000 km (1,243 to 1,864 mi), having moved faster than any other known plate.

German geologists determined that the Indian Plate was able to move so quickly because it is only half as thick as the other plates which formerly constituted Gondwanaland. 

The collision with the Eurasian Plate along the modern border between India and Nepal formed the orogenic belt (continental collision )

The process of mountain formation, especially by a folding and faulting of the earth's crust) that created the Tibetan Plateau and the Himalayas (3 crore yrs back ,Alpine Age).

Indian Subcontinent- The fastest continent

As of 2009, the Indian Plate is moving northeast at 5 cm/yr (2 in/yr), while the Eurasian Plate is moving north at only 2 cm/yr (0.8 in/yr). India is thus referred to as the "fastest continent". This is causing the Eurasian Plate to deform, and the Indian Plate to compress at a rate of 4 mm/yr (0.15 in/yr).

That is why Himalaya’s top is actually a sea bed and sea fossils are found. Here lime stone rock is found.

 Division of Himalaya:-

From West to East:-

(i) Punjab Himalaya –

It is the western most part of Himalaya in between Indus river & Satluj river. It consists of following remarkable places:-

A] Mansarovar – Famous for Kailash Mansarovar yatra.It’s the origin of Indus, Satluj & Brahmaputra.

B] Rakastal Origin of Satluj is situated here.

(ii) Kumaon Himalaya –

It is in between Satluj and Kali river.

Major sites are Gangotri (Origin of Ganga), Yamunotri (origin of Yamuna). Badrinath, Kedarnath etc.

(iii) Nepal Himalaya –

Between Kali & Tista river. It has the world highest peak Mount Everest and Kanchanjunga.

 Mt. Everest is known as chomo lagma / Camolagma in Tibet.

The Nepalese called it as Sagar Matha.

Kanchanjunga(Sikkim) is highest peak under India’s control is situated here.

(iv) Assam Himalaya –

 Between Tiesta & Dihang river. It has Naaga hills which divides India & Burma.

Purvanchal are the southward extension of the Himalayas.

Purvanchal (or Eastern Hills) run along the Indo-Myanmar border extending from Arunachal Pradesh to Mizoram.

They form the watershed between India and Myanmar.

They run in the shape of a crescent with its convex side pointing towards the west.

 However, they do not form continuous mountain chain and are comparatively lower in elevation when compared to Himalayas.

From North to South:-

(i) Greater Himalaya:-

Also Known as Himadri. It is the longest range. It is tallest range of Himalaya. Its average height is 6000 m. Mt. Everest, Kanchanjunga are the parts of it. It is also known as inner Himalaya. Mansarovar is situated here.

(ii) Himachal/Lesser Himalaya -

Also known as Himachal or Middle Himalaya. It’s average height is 2,600 m. The important sites are Shimla, Myssori, Gulmerg, Daejling etc.

(iii) Sub Himalaya:-

Also known as Shivalik or outer Himalaya. Its average height is 1300 m. It has places like Dehradun, Haridwar etc.

(iv) Karakoram:–

This is north of Greater Himalaya. It is also known as Tethyus Himalaya. It has world’s 2^nd highest peak (kara koram). It is also known as Godwin Austin (8611m). K₂ is India’s highest peak. But Since it is under POK, it is not under India’s Possession.

The Karakoram is situated in the disputed state of Jammu and Kashmir. It has more than sixty peaks above 7,000 m (22,966 ft), including K2, the second highest peak in the world 8,611 m (28,251 ft). K2 is just 237 m (778 ft) smaller than the 8,848 m (29,029 ft) Mount Everest.

The range is about 500 km in length and the most heavily glaciated part of the world . 

The Siachen Glacier at 70 km (43 mi) and the Biafo Glacier at 63 km (39 mi) rank as the world's second and third-longest glaciers outside the polar regions.

Hindu Kush range –

To the west of the northwest end of the Karakoram, lies the Hindu Raj range, beyond which is the Hindu Kush range (The mountain range separates Central Asia from South Asia).

The Hindu Kush is an 800-kilometre-long (500 mi) mountain range in Central and South Asia to the west of the Himalayas.

 It stretches from central and western Afghanistan into northwestern Pakistan and far southeastern Tajikistan. 

The southern boundary of the Karakoram is formed by the Gilgit, Indus and Shyok rivers, which separate the range from the northwestern end of the Himalayas.

The Pamirs -

THE UNIQUE OROGRAPHIC feature known as the Pamir Knot takes its name from the mountains on which it is centered, the Pamir.

The “knot” refers to the convergence of some of the world’s major mountain ranges, including the TIAN SHAN, Karakorum, Kunlun, HINDU KUSH, and Pamir systems .

 Pamirs, also called Pamir, highland region of Central Asia. The core of the Pamirs is in the highlands of Tajikistan .

The Pamir Mountains were created by crustal tectonics. About 60 million to 20 million years ago, the Indian continental plate subducted under the Eurasian plate and, with the effects of extrusion and uplift of the Indian plate, several huge mountains were formed .

These mountains now radiate from the Pamirs and most of them are more than 4,000 m in height.

Various Passes of Himalaya –        

1- Jojilla Pass [between Shrinagar & Leh].                                                                                                                 

2- Karakoram Pass [between Jojila & Yaarkandh].                                                                                                  

3- Rohtang Pass [Himachal Pradesh]                                                                                                                         

4- Shipki pass [Himachal Pradesh]                                                                                                                             

5- Mana pass [Uttarakhand] – goes to China/Tibbet.It is the pass for Kailash Mansarovar.                                       

6- Jelepla   Pass, Sikkim                                                                                                                                 

 7- Nathula pass, [Sikkim]                                                                                                                                             

8- Bombdila pass [Arunachal Pradesh].

Khbar Pass

The Khbar Pass or Khyber Pass connects Pakistan and Afghanistan. This pass was an important segment of the old Silk Road. From time immemorial, the Khbar Pass has functioned as a business route amid South Asia and Central Asia.

Bolan Pass

The Bolan Pass is a mountain pass across the Toba Kakar Mountain Range in Balochistan Province in West Pakistan. It is located at a distance of 120 km from the boundary of Afghanistan.

Due to its important location, aggressors, merchants and migratory ethnic groups have also made use of the Bolan Pass as an entrance to and from Southern Asia.

Lipulekh Pass-

Himalayas, Uttarakhand, India

Lipulekh is a Himalayan pass connecting the Kumaon region of Uttarakhand in the Pithoragarh district in India with the old trading town of Taklakot.

Effect of jet streams on Indian climate and monsoon-

   - Indian Monsoon Mechanism and the Role of Sub-Tropical Jet Streams

-Westerly Jetstream brings the western cyclonic disturbances(originate over the Mediterranean Sea) that enter the Indian subcontinent from the west and the northwest during the winter months. An increase in the prevailing night temperature generally indicates an advance in the arrival of these cyclones disturbances. 

-The onset of SW Monsoon over the Indian subcontinent is driven by the shift of the subtropical westerly jet northwards from over the plains of India towards the Tibetan Plateau.

- This shift is due to the intense heating of the Plateau during the summer months.

-This shift of the westerly jet to the north of the Himalayas is not a slow and gradual process, as expected for most changes in weather patterns. The primary cause of these is believed to be the height of the Himalayas.

-As the Tibetan Plateau heats up the …low pressure created over it pulls the westerly jet northwards. Due to the lofty Himalayas, the westerly jet is inhibited (prevented) from moving northwards.

-However, with continuous dropping pressure, sufficient force is created for the movement of the westerly jet across the Himalayas after a significant period.

-As such, the shift of the jet is sudden and abrupt causing the bursting of SW Monsoon rains onto the Indian plains. The reverse shift happens for the NE Monsoon.

-The above-mentioned Jet Stream theory also explains the variability in timing and strength of the Monsoon.