Layers of the Earth

1. Layers of the Earth • Inner Core • Outer Core • Lower Mantle • Asthenosphere • Lithosphere (crust)

2. Inner core • Made of iron and nickel • Temperature reaches 5000 degrees Celsius • However, is solid due to the extreme pressure it is under

3. Outer Core • Made of mostly nickel and some iron • Temperature is about 3800 degrees Celsius • This layer is liquid

4. Mantle • Thickest layer • Made of silicon, oxygen, iron and magnesium • High temperature and pressure in the mantle allows the solid rock to flow slowly – plasticity • There are differences in the temperature within the mantle which produce convection currents

5. Asthenosphere • Part of the upper mantle • Made of hot, semi-solid materials much like the consistency of asphalt • This layer has the ability to glide over the lower mantle • This movement causes the plates of the crust to move

6. Crust • The very thin outer layer of the Earth • Main elements are oxygen and silicon • Crust is found both on land (continental crust) and under the ocean (oceanic crust) • The crust is broken into smaller pieces • The crust’s materials are less dense than the materials under it.

7. Continental Crust • 20 to 70 kilometers thick • Composed mostly of granite

8. Oceanic Crust • Relatively thin, between 5 to 10 kilometers thick • Primarily composed of basalt

9. Lithosphere • Includes the oceanic and continental crust and the uppermost part of the mantle. • Is considered to be cool and rigid • Is the zone of earthquakes, mountain building, volcanoes, and tectonic plate movement.