Tnpsc and Upsc Notes Pdf
Pravin Babu R 
Diastrophism in Geography Definition All the processes which move, elevate or build up portions of the earth crust comes under Diastrophism. Orogenic The processes involving mountain building by severe folding and affecting long and narrow belts of the earth crust. In this process, the crust is severely deformed into folds. Epeirogenic The process that involves … Read more
Post-Drift Studies The post-world war -II period added new information regarding the continents. In particular, the ocean floor mapping gave new dimensions in the field of study of oceans and continents. Convectional Current Theory The convection currents operating in the mantle portion were discussed by Arthur Holmes in the 1930s. These currents are caused by … Read more
Volcanic Landforms The landform formed due to volcanic eruptions is divided into extrusive and intrusive landforms. This is based on the magma, that cools within the crust or above the crust. Intrusive landforms are formed under the surface of the earth when the magma cools and gets solidified. Extrusive landforms are formed when the magma … Read more
An earthquake in simple words is the shaking of the earth. It is a natural event and it is caused due to release of energy that generates seismic waves that travel in all directions. Why does the earth shake? The shakes are due to the release of energy, that occurs along the fault. The fault … Read more
Rock cycle and Types of rocks The rock cycle is a continuous process by which the old rocks are transformed into a new one. The changes are caused by various chemical and physical processes. There are three major types of rocks and they are igneous rocks, sedimentary rocks, and metamorphic rocks. Rocks The earth’s crust … Read more
Minerals and rocks The earth is made of different kinds of elements and these elements are in solid form in the outer layer and hot and molten form in the interior of the earth. Around 98% of the total crust of the earth is composed of eight elements: Oxygen – 46.6%, Silicon- 27.72%, Aluminium – … Read more
The Earth’s radius is 6370 km. It is practically impossible to reach the centre of the Earth and conduct research on it. Due to this scientists and engineers are collecting information on the Interior of the Earth based on estimates and inferences from various sources arising from the Earth. These estimations are classified as Direct … Read more
Indian Standard Time, also known as IST, is the official time observed throughout India. It is calculated based on the standard meridian of India, which is 82°30’E longitude. This Indian Standard Time Meridian passes near Mirzapur in Uttar Pradesh. As per international timekeeping, IST of India is +5:30 hours ahead of Greenwich Mean Time (GMT) … Read more
Physical Geography Solar System Earth Latitude and Longitude Motions of Earth – Rotation, Revolution, Inclination of Earth Axis Local and Standard Time International Date Line, Calendar Eclipses Interior of the Earth Source of Information – Direct, Indirect – Earth Quakes Volcanoes, crust, mantle, core etc Rocks Rocks & landform & Soils Rock Cycle – Types … Read more
Rotation and revolution of earth Earth has two types of Motions. They are Rotation and Revolution. Rotation is the movement of the earth on its axis. Earth takes 24 hours for one rotation around its axis. This period of rotation is known as Earthday. Revolution is the movement of the earth around the sun in … Read more