1. Earth’s Layers

2. Crust
 Outer most layer
 Thinnest
 5 to 100 kilometer (km) thick
 Temperatures range from 0°
C to 1000°C

3. Crust
 Composition: mostly
silicon, oxygen, sodium, small
amounts of magnesium,
potassium, and iron.

4. Crust
“Two Types”
Continental Crust
Thickestup to 100 km at
mountains
Most abundant rock is
granite

5.  Oceanic Crust
Asthin as 5 km
Most abundant rock is basalt
Density averages 3g per cm³

6. Crust/Mantle
Mohorovicic
Discontinuity (Moho):
Transitionboundary
between the crust and
mantle

7. Crust/Mantle
Mohorovicic
Discontinuity (Moho):
This boundary marks a
significant change in
chemical composition.

8. Mantle
 67% of Earth’s mass
 2,900 km thick
 Temperature ranges from
1000° C to 3700 ° C

9. Mantle
Density averages from
4.3g to 5.4g per cm³
Composition: mostly
silicon, oxygen,
magnesium, and iron

10. Mantle
 Convection currents occur
here

11. Mantle
Divided into 3 layers:
1. Lithosphere
2. Asthenosphere
3. Mesophere

12. Mantle
 Lithosphere:
10 to 300 km thick
Solid and made up of crust
and mantle material
VERY rigid
Divided into sections called
plates

13. Mantle
Asthenosphere
250 km thick
Soft layer that allows
plates to shift

14. Mantle
Mesosphere
2550km thick
Lower part of the mantle

15. Core
Divided into 2 layers:
1. Outer Core
2. Inner Core

16. Core
Outer Core
Liquid
2200 km thick

17. Core
Outer Core:
Composition: Iron and
Nickel, 10% sulfur and
oxygen

18. Core
Outer Core:
Density: 10g to 12g per
cm³
Temperature: 4000° to
5000° C

19. Core
Inner Core:
Solid
1230 km thick
About 6380 km beneath
Earth’s surface

20. Core
 Inner Core:
Composition: Iron and
Nickel
Density: 15 g per cm³
Temperature: 5000° to
6000° C

21. Earth’s Layers
 Scientistsuse indirect
methods to gain information
and knowledge of Earth’s
interior (example:
earthquakes).

22. Earth’s Layers
 Seismic waves from
earthquakes travel at
different speeds depending
on the density and
composition of the ground
they move through.

23. Earth’s Layers
Scientists are able to
take this information and
learn about the interior of
Earth.