Indian Drainage System

Drained basin: - The area drained by single river is known as drained basin.

Water divide: - An upland that separate two drainage basin is known as water divide.

Indian rivers are divided into two major group.

●       the Himalayan rivers

●       the Peninsular rivers

A river with its tributary is called river system.

Himalayan rivers

The river originates in the Himalayan. The Himalayan rivers are perennial rivers, means they have water throughout the year. These rivers receive water from rain as well as from melted snow from the mountains. Himalayan river system divided into Indus river system and Ganga-Brahmaputra river system.

Volcanoes

Volcanoes are classified on the basis of nature of eruption and the form developed at the surface. Major types of volcanoes are as follows: -


Shield Volcanoes: -
Shield Volcanoes are the largest of all the volcanoes on the earth. Barring the basalt flows.


Composite Volcanoes:-
They are characterized by eruptions of cooler and more viscous lavas than basalt. These volcanoes often result in explosive eruptions, large quantities of pyroclastic material and ashes find their way to the ground.

Layers of earth

We cannot directly observed earth's interior by mining and drilling, it is possible for few kilometers because of rapid increase in temperature. So some indirect observations are taken to known earths interior.  
There are 3 layer of earth. 
1. Crust
2. Mantle
3. Core


1. Crust: -
It is the outermost solid part of the earth. The thickness of the crust varies under the oceanic and continental areas. Oceanic crust is thinner as compared to the continental

Earthquak

In the interior of earth when magma(magma is molten rocks) is hot it goes up and when it is cool it goes down this process make a plate to move. The friction between the plates prevents plates to move and this cause the storage of kinetic energy in the plates. A point reached when these plates move and all the stored kinetic energy is released .When stored kinetic energy of plates is released than waves produced in all directions. The point where the energy is released is called the ‘focus’ or
‘hypocentre’, this point is beneath the surface, the point on the surface, above the focus is called ‘epicenter’. Epicenter is the first to experience the waves of earthquake. All natural earthquakes take place in the lithosphere. An instrument called ‘seismograph’ records the waves reaching the surface. Fault (fractures between two blocks of rock) is formed where two plates moves alongside. 

There are basically 2 types of waves produced in earthquake.

1. Body waves  

2. Surface waves

The Himalayan Mountains

Himalayan is young and fold mountain. It stretches over the northern border of India. These mountain ranges run in a west-east direction from the Indus to the Brahmaputra. The Himalayas represent the loftiest and one of the most rugged mountain barriers of the world. They form an arc, which covers a distance of about 2,400 Km. The Himalaya consists of three
parallel ranges in its longitudinal extent i.e. the great or inner Himalayas and himadri, himachal or lesser Himalayas, the outer Himalayas or shiwalik rang. A number of valleys lie between these ranges. Himalayan stretched from pamir knot.

1. The great Himalayas= the northernmost range. It is the most continuous range of the world consisting of the loftiest (tallest) peaks. All the prominent Himalayas peaks are here. The folds of Great Himalayas are asymmetrical in nature. The core of this part of Himalayas is composed of granite. There are numbers of glaciers.

2. Lesser Himalayas = it is south to the himadri range. most rugged(rough, uneven) mountain system and is known as Himachal or lesser Himalaya.mainly composed of highly compressed and altered rocks.the Pir Panjal range is longest of lesser Himalayas. The Dhaula Dhar and the Mahabharat ranges are also prominent ones.This range consists of the famous valley of Kashmir (lies between the Pir Panjal and the Zaskar ranges), the Kangra and Kullu Valley in Himachal Pradesh