Layers of earth

A) Lithosphere

B) Atmosphere

C) Hydrosphere

D) Biosphere

1) Lithosphere

The rigid outer part of the earth consisting of crust and upper mantle. The top most solid layer is called lithosphere. It is up to 100km deep including crust and some portion of upper mantle.

1) Crust:

The outer most layer of the Earth is known as earth's crust. On an average it is 30km deep. it can be up to 70KM under high mountains and up to 8km under ocean.

• It is known as 'Sial' because of abundance of silicon and aluminium.

2) Mantle:

the second layer of earth is called mantle.It is separated as upper mantle up to 700 km and lower mantle from 700-2900 km.

• It is made of dense and rigid rocks which have the predominance of magnesium and silicon, known as 'Sima'.

3) Core:

The innermost layer is called core. It lies from 2900km-6371km.

• It is called 'Nife' it probably contains alloy of nickel and iron
• It also has two parts-A liquid outer core separated by inner core.

Asthenosphere

It is the second plastic layer under lithosphere. It is stretches from 100Km to 400km.

B) Atmosphere:

The vast expanse of air which envelopes the earth is called atmosphere.

C) Hydrosphere:

The Hydrosphere includes the water that is on surface of the planet, underground and air. A planet's hydrosphere can be liquid, vapour or ice.

D) Biosphere:

The earth planet along with the atmosphere (Air,Land,Water) that sustains life is called biosphere.