1. EARTH’S COMPOSITION

2. Proportions of the Earth’s Elements
Element Percent by Weight
Iron
Oxygen 29.5
Silicon
Magnesium 12.7
Other

3. Elements of the Earth’s Crust
Element Percent by Weight
Oxygen
Silicon
Aluminum
Iron
Calcium
Sodium
Potassium
Magnesium
All Others

4. Earth’s Layers Defined Based on 2 Criteria Composition (3 Layers)
Crust
Moho: Boundary between the Crust and Mantle
Mantle
Core
Structure (5 Layers)
Lithosphere – Composition: Upper Mantle & Crust
Asthenosphere – Composition: Mantle
Mesosphere – Composition: Mantle
Outer Core - Core
Inner Core - Core

5. COMPOSITIONAL DIFFERENCES

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

7. The Crust Outer layer 5-100 km thick Silica Rich 2 types of crust
Oceanic (very dense, made of basalt)
Continental (less dense, made of granite)

8. Oceanic and Continental Crust

9. The Mantle
Middle layer
Magnesium Rich
Very thick layer

10. The Core
Made mostly of iron
1/3 of the earth’s mass
Very hot

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

12. STRUCTURAL DIFFERENCES

13. Physical Structure of the Earth (5 Layers)
Lithosphere- rigid outer layer (crust)
Asthenosphere- solid rock that flows slowly (like hot asphalt)
Mesosphere- middle layer
Outer Core- liquid layer
Inner Core- solid, very dense

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

15. THE END