1. The Structure of the Earth

2. 3 Composition Layers: Based on what the layer is made of

3. Compositional Layers of Earth

4. 1. Crust Outer layer, very thin Two types of crust:
Continental Crust (land) – thicker & less dense
Oceanic Crust (land under the ocean) -thinner and more dense

5. How can you tell Oceanic Crust is more Dense?

6. 2. Mantle Contains 67% of Earth’s Mass
We have not actually seen the mantle.
Made of solid rock that is able to flow.

7. 3. Core
Made mostly of Iron and other very dense materials.

8. 5 Physical Layers of the Earth:
Based on the physical state of matter: solid, liquid, or gas.

9. 1. Lithosphere “Rock Sphere” Outermost rigid layer
Divided into pieces called tectonic plates
Solid
The least dense of Earth’s layers.

10. Tectonic Plates make up the Lithosphere

11. 2. Asthenosphere “Weak Sphere”
Soft layer of mantle. Made of solid rock that flows very slowly like putty (same rate fingernails grow).
Solid (but can flow like a liquid)

12. 3. Mesosphere “Middle Sphere” Strong lower mantle.
Solid rock that flows in circles, heating and cooling.
Has convection currents

13. 4. Outer Core Liquid layer Made of melted Iron Very Dense
Seismic waves help us to know this layer is liquid

14. 5. Inner Core
Solid
Iron
Most dense layer
Iron causes magnetic fields

16. Structural layers