L-1 The Components Of Environment (Part-2) Class-7
51This video is about the four spheres of the Earth i.e. Lithosphere, Atmoshphere, Hydroshpere and Biosphere and biodiversities.
Lithosphere:- It is the layyer of Earh consissting of rock matrial. It has two parts:- Sial and Sima. Sial:- The Lithosphere composed of rocks rich in Silica and Aluminium called Sial found over continents.
Sima:- Below the Sial layer the rocks are mainly rich in Silica and magnesia called Sima found below the bottom of ocean basins. The density is higher than Sial because the density increases with depth.
Atmoshpere:- It is a thin layer of air composed of mixture of gases that envelopes our Earth. The total mass of atmosphere 99% exist within 32 km of height from the Earth surface. The density from the atmosphere is maximum near the Earth surface but it decreases rapidly eith height.
Hydroshpere:- It is the sphere of water which is present in lakes oceans, rivers, lakes and other water bodies on the Earth surface. Water bodies cover 71% of the Earth surface. About 43% of total area covered by water lies in northern hemisphere whereas remaining 53% lies in southern hemisphere.
Biosphere:- Biosphere means the sphere of life. Biosphere is the narrow zone of contact between all the three spheres. it include atmosphere, hydrosphere and Lithosphere.
Biodiversities:- The Earth is full of diversities. Their is diversities in land, soil, plants and animals. THis processs of diversification has occured largely over long period of time resulting in emergence of new species of plants and animals. The wide range of species is known as biodiversities.