Geography

Gondwana coal makes up to 98 per cent of the total reserves and 99 per cent of the production of coal in India. Satpuras, denudation [weathering + erosion] has exposed coal bearing Gondwana strata.The carbon content in Gondwana coal [250 million years old] is less compared to the  Carboniferous coal [350 million years old][Almost Absent in India] because of its much … Read more

Seismic waves are generated due to the release of the energy during an earthquake. They behave differently in different physical mediums and hence provide a good idea how the interior of earth must be. Broadly there are three types of seismic waves: Primary waves: (P) – Waves are longitudinal waves. i.e. The motion of particles … Read more

Batholiths A large body of magmatic material that cools in the deeper depth of the crust develops in the form of large domes. They appear on the surface only after the denudational processes remove the overlying materials. They cover large areas, and at times, assume depth that may be several km. These are granitic bodies. … Read more

The theory of plate tectonics proposes that the earth’s lithosphere is divided into seven major and several minor plates. The movement of the plates results in the building up of stresses within the plates and the continental rocks above, which leads to folding, faulting and volcanic activity. The major plates are surrounded by fold mountains, … Read more

Most important sorts of ocean deposits are: Terrigenous Deposits Body of water Deposits. There are loose sediments, deposited on the ocean bottom. These are ocean deposits. They vary from location to location. The study of ocean deposits is vital in beneath standing the rocks exposed on the earth’s surface that were once set under ocean. … Read more

Flood is a natural disaster which can never be avoided, India being one of the worst flood hit tropical country in the world which causes huge economic and emotional losses. We cannot afford to ignore flood but we can manage it. Around 12% of the total area i.e. 40 million hectare is prone to flood. … Read more

In a penumbral eclipse, the Full Moon enters the Earth’s penumbral shadow. The light from the Earth is partially blocked, and the Moon grows dimmer. In principle, a penumbral eclipse can be a partial penumbral eclipse (with only part of the Moon in the penumbra) or a total penumbral eclipse, where the entire Moon is in the penumbra; however, … Read more

This theory was put forth by Alfred Wegener. The continental drift hypothesis was developed in the early part of the 20th century. According to this theory, e continents were once united into a single supercontinent named Pangaea, meaning all earth in ancient Greek. He suggested that Pangaea broke up long ago and that the continents … Read more

Coal is an important raw material for heavy industries. Its abundance ensures a rapid industrial growth.  But coal mining has its own cost and it has negative externalities. Major problem with coal mining is threat to environment. Open cast mining results in air pollution because of coal dust and coal transportation leading to suspended particulate … Read more

The practice of growing two or more crops simultaneously in a same field in definite row pattern is called intercropping. The row pattern may be in the ratio of 1:1, 1:2, and 1:3. It means after one row of main crop, one, two, or three rows of intercrops can be grown. Objective of intercropping: The basic objective … Read more