1. Formation of the Earth
In the beginning

2. Just a lot of Gas Space contained a lot of gasses and dust
That gas and dust began to condense and heat up
Matter in the middle heated so much the gasses ignited
BANG!

3. After the Bang After the gasses exploded it threw material out
As the material moved away from the sun it started to cool forming planets

4. Forming Earth
Earth was formed from the dust and gasses that were left after the bang
Earth started off as a rock. It was hit by meteors over billions of years, which added to the mass of the planet.
As the planet cooled the heavier, more dense metals began to sink to the inner part of the earth

5. Formation of the Earth

6. Layers of the Earth As the molten earth material cooled layers formed
Crust
Mantle
Outer core
Inner core

7. How do we know? Can’t see into the earth
Have only drilled into a small part of the earth
Learned what we know by studying seismic waves and how they travel

8. Outer and Inner Core

9. The Crust The crust is the outermost layer of the earth
It is made of two types of crust
Continental ( km)
Oceanic (5-10 km)
It is not very thick
5-100 km thick
We have only drilled about 5 miles (8 km) into the crust
It’s a solid
Where we live

10. The Mantle Is found under the crust
Is made mostly of iron (Fe) and magnesium (Mg)
Where most of the earth’s heat is
Has convection cells that cause the plates to move
Volcanoes give us a clue to what is under the crust

11. Convection – hot rises, cold sinks

12. The Outer Core Is about 2200 km thick
Made mostly of iron (Fe) and nickel (Ni)
Is a liquid
The outer core is liquid, unlike the inner core.

13. The Inner Core Is a solid Is 1228 km thick
Due to extreme pressure from all the other layers of the earth
Is 1228 km thick
Made of mostly iron (Fe) with some nickel (Ni)

14. Other Names Crust and upper mantle – lithosphere
Where the tectonic plates are found
Bottom of the upper mantle – asthenosphere
Where the convection cells are
Lower mantle - mesosphere

15. Draw the layers of the Earth
Pages 90 and 91 in “Inside the Restless Earth”
Include the following words; Crust, mantle, Outer Core, Inner Core, Lithosphere, Asthenosphere, Mesosphere.