1. Journey to the Center of Earth

2. Layers of the Earth Crust Lithosphere Asthenosphere Mantle Outer Core
Inner Core

3. Crust This is the layer that we live on
The thickness ranges from five miles under the oceans to 25 miles under the continents
Consists of cooled rock- granite and basalt
It is the thinnest layer of the earth

4. Lithosphere
Floats on the asthenosphere and includes all of the crust and part of upper mantle
Cool solid portion of the Earth

5. Asthenosphere
A zone of partially melted rock in the upper mantle

6. The Mantle This layer is semi- liquid
It consists of magnesium, iron, and silicon
It is 3000 km wide
It is more solid closer to the surface

7. The Outer Core This consists of liquid due to the high temperatures
It is 2100 km wide
This layer consists of nickel and iron

8. The Inner Core This layer is solid.
The reason it is solid is due to the high pressure exerted on it from the outside layers.
It consists of the metals nickel and iron.
Its temperature is 6,000 C.
Its width is 2,100 km.

9. Earth’s interior layers.
The major layers of the Earth consist of the crust, lithosphere, asthenosphere, mantle, outer core and inner core.

10. THE CRUSTAL SURFACE. CONTINENTAL CRUST – i
is between 20 and 60 km thick. It is composed of granitic rocks, which are less dense than basaltic rocks of the oceanic crust. So, most of continental crust is above sea level.
OCEANIC CRUST -
is only about 10 km thick. It is composed of basaltic rocks, which are more dense than granitic rocks of the continental crust. So, oceanic crust is below sea level.

11. Composition of the Earth.

12. THE THEORY OF PLATE TECTONICS
The framework explains how and why the surface of the earth constantly changes is called theory of plate tectonic.
The theory states that the earth’s outer shell, the lithosphere is divided into eight large plates.
Because each plate moves as a single unit, the interiors of the plates are generally stable. All major activity such as earthquake or volcano occur along the plate boundaries.