1. Earth Structure Notes

2. Composition (What it is made of)
Crust
Mantle
Core

3. The Crust Outer layer 5 - 100 km thick (3 – 60 miles thick)
Made of oxygen & silicon
2 types of crust
Oceanic (very dense, made of basalt)
Continental (less dense, made of granite)

4. Oceanic and Continental Crust
Oceanic crust 3 – 5 miles thick
Continental crust on average 18 miles thick

5. The Mantle Middle layer Very thick layer Made of iron & magnesium
2,900 km thick
Solid near core
Upper part is semi-solid

6. The Core Made mostly of iron & some nickel 1/3 of the earth’s mass
Very hot
3,428 km thick

7. Earth’s Layers How are the earth’s layers similar to an egg?
Shell=crust
Egg white=mantle
Yolk=core

8. Physical Structure of the Earth (5 Layers)
Lithosphere
Asthenosphere
Mesosphere
Outer Core
Inner Core
(LAMOI)

9. The Lithosphere Rigid outer layer (crust + top part of mantle)
Made of oxygen & silicon
Made of moving tectonic plates
60 – 300 km thick

10. Tectonic Plates Earth’s lithosphere is broken into about 19 pieces
These plates move on top of the asthenosphere

11. The Asthenosphere
Semi-solid; solid but flows like liquid, called PLASTICITY
Part of Mantle
Plates float on this layer; moved by convection currents
250 km thick

12. The Mesosphere Middle layer of Earth Very strong solid layer
Lower part of mantle
2,550 km thick

13. The Outer Core Liquid layer 4,000 – 5,000 Celsius
Made up of nickel & iron
2,200 km thick

14. The Inner Core Solid, very dense 6,000 Celsius Made up of iron
1,228 km thick
Extreme pressure makes it solid even though it is still very hot