Himalayan Mountain System: Formation, Divisions, and Significance Explained

Formation of Himalayas

The Himalayas are young fold mountains. They formed due to the collision of the Indian Plate with the Eurasian Plate. This process began approximately 50 to 60 million years ago. The Indian Plate continues to move northward, causing the Himalayas to rise even today. This ongoing tectonic activity makes the region seismically active. The Tethys Sea, which once existed between these two plates, was uplifted and folded to form the mountain range. Sediments from the Tethys Sea floor were compressed and elevated, creating the various ranges we see today. The immense pressure from the colliding plates resulted in the formation of several parallel ranges, each with distinct geological characteristics. This geological history is vital for understanding the region's unique features and natural resources.

Major Himalayan Divisions

The Himalayan mountain system is divided into three parallel ranges. These are the Greater Himalayas (Himadri), the Lesser Himalayas (Himachal), and the Outer Himalayas (Siwaliks). The Greater Himalayas are the northernmost and highest range, with an average elevation of over 6,000 meters. It includes the world's highest peaks like Mount Everest (8,848.86 meters) and Kanchenjunga (8,586 meters). The Lesser Himalayas lie south of the Himadri, with elevations between 3,700 and 4,500 meters. This range is known for popular hill stations such as Shimla, Manali, and Darjeeling. The Outer Himalayas, or Siwaliks, are the southernmost and lowest range, with elevations between 900 and 1,100 meters. These ranges are composed of unconsolidated sediments brought down by Himalayan rivers. The valleys between the Lesser Himalayas and the Siwaliks are known as 'Duns' in the west (e.g., Dehradun) and 'Duars' in the east.

Regional Divisions and Peaks

Besides the parallel divisions, the Himalayas can also be divided regionally from west to east. These divisions are based on river valleys. The Punjab Himalayas lie between the Indus and Satluj rivers. The Kumaon Himalayas are situated between the Satluj and Kali rivers. The Nepal Himalayas, the longest section, extend between the Kali and Tista rivers. Finally, the Assam Himalayas are located between the Tista and Dihang rivers. Each regional division has unique characteristics and prominent peaks. For instance, the Kumaon Himalayas are home to Nanda Devi (7,816 meters). The Nepal Himalayas contain the highest concentration of the world's tallest peaks. Understanding these regional divisions helps in grasping the vastness and diversity of the Himalayan range. Many important passes, such as Zoji La and Nathu La, are also found within these regional sections, facilitating trade and movement.

Significance for India

The Himalayas play a crucial role in India's geography and climate. They act as a natural barrier, protecting India from cold winds blowing from Central Asia. This barrier effect helps maintain a warmer climate in the Indian subcontinent. The Himalayas are also the source of major perennial rivers like the Ganga, Yamuna, and Brahmaputra, which are vital for agriculture and provide freshwater to millions. The mountains influence the monsoon pattern, forcing moisture-laden winds to shed their rain on the Indian plains. They are rich in biodiversity, hosting numerous unique plant and animal species. Furthermore, the Himalayas are a significant source of hydroelectric power and offer immense potential for tourism. Their strategic location also holds geopolitical importance for India's northern borders. The ecological balance of the Himalayas is critical for the entire subcontinent.

Important Keywords Explained

Tethys Seaplace

An ancient ocean that existed between the supercontinents of Gondwana and Laurasia. Its closure and the subsequent collision of the Indian and Eurasian plates led to the formation of the Himalayan mountain range. Sediments deposited in the Tethys Sea were uplifted and folded to create the mountains, providing crucial evidence for plate tectonics.

Plate Tectonicsconcept

A scientific theory explaining the large-scale motion of Earth's lithosphere. It describes how the Earth's outer shell is divided into several large plates that glide over the mantle. The collision of the Indian and Eurasian plates, a key aspect of plate tectonics, is responsible for the formation and ongoing uplift of the Himalayas.

Dunsplace

Longitudinal valleys found in the Outer Himalayas (Siwaliks) and the Lesser Himalayas. These valleys are formed by the deposition of sediments by rivers. A famous example is Dehradun in Uttarakhand. In the eastern part of the Himalayas, similar valleys are known as 'Duars'. They are fertile and often densely populated.

Additional Facts & Context

• The average width of the Himalayas is about 400 km in Kashmir and 150 km in Arunachal Pradesh.
• Kanchenjunga, the third highest mountain in the world, is located in the Nepal-India border region (Sikkim).
• The Himalayas cover an area of approximately 500,000 square kilometers.
• The Nanga Parbat peak (8,126 meters) marks the westernmost extremity of the Greater Himalayas.
• The Namcha Barwa peak (7,756 meters) marks the easternmost extremity of the Greater Himalayas.