2. By Rana Faizan Saleem Roll.No (10)

3. Earth Layers The Earth is divided into four main Layers: 1) Crust 2) Mantle 3) Outer-Core 4) Inner-Core

4. The Crust It is an outer layer. It is 5-100 km thick. It makes up 1% of Earth. The crust is broken into many pieces, called Plate tectonics. Types of Earth Crust: There are two types of Crust. 1) Oceanic(very dense, made up of Basalt) 2) Continental(less dense, made up of granite)

6. The Mantle The mantle is the layer below the Crust. It is the largest layer of the earth. It consists of molten materials. It is very thick layer of earth. It is divided into 2 regions: (i) Upper Mantle (ii) Lower Mantle

7. The Core Made mostly of iron. 1/3 of the earth mass. It is very hot layer. It divides into 2 layers: (i) Outer-Core (ii) Inner-Core

8. Outer Core The outer core is liquid. It is very dense. It is made up of iron.

9. Inner Core The Inner core is a solid. The inner core of the Earth has temperatures and pressures so great that the metals are squeezed together and are not able to move about like a liquid.

10. Earth Layer’s How Earth layers are similar to an egg? Shell=Crust Egg White=Mantle Yolk=Core

11. Physical Structure Of The Earth  Lithosphere: rigid outer layer (crust)  Asthenosphere: solid rock that flows slowly  Moho Discontinuity: the boundary between the Earth’s crust and the upper mantle  Mesosphere: middle layer  Outer core: liquid layer  Inner core: solid, very dense

12. Earth Waves There are two types of earth waves:  Body Waves (P and S Waves)  Surface Waves (Rayleigh and Love Waves) Body Waves: (i) P-Waves(Primary Waves) These are compressional waves. Travels through liquid,gas and solid. These waves are very faster. Particles moves in parallel direction of waves motion.

13. S-Waves(Shear/Secondary) These waves are transverse. These waves only passed through solids. These waves travels slowly than P-waves. Particles moves perpendicularly (up and down) to the direction of wave motion.

14. Earth Atmosphere There are 4 layers of earth atmoshphere. 1. Troposphere Where we are living. 12 km from the surface of earth. All earth weather occurs here. 2. Straitosphere Where airoplane fly It has ozone layer which absorb U.V rays. 50 km from the surface of earth.

15. 3. Mesosphere It is a coldest region of atmosphere. It prevents earth from large rock object(Meteoroids). 80 km from the surface of earth. 4. Thermosphere Its Temp is high due to U.V waves. It has two types: (i) ionosphere: (Inner surface of Thermosphere) (ii) Exosphere: (Outer surface of Thermosphere)