1. Earth’s Layers

2. We Have 2 ways of Dividing Earth’s Layers:

3. Earth is divided into 3 compositional layers:
1. Crust
2. Mantle
3. Core

4. CRUST: Location: outermost layer Temperature: 0°C to 1,000°C
Thickness: 5km to 100 km
Composition:
Oxygen, Silicon, and
Aluminum

5. 2 TYPES OF CRUST:
Oceanic crust is very thin & dense.
Continental crust is thick but less dense.

7. MANTLE:
Location: below the crust.
Temperature: 1,000°C to 3,700°C
Thickness: 2,900 km
Composition:
Solid and molten rock, most of Earth’s mass

8. CORE:
Location: Earth’s center
Temperature: 3,700°C - 7,000°C
Thickness: 3,500 km (combined)
Composition: mostly iron, some nickel
Divided into 2 layers:
Outer Core
Inner Core

10. Earth is divided into 5 physical layers:
1. Lithosphere
2. Asthenosphere
3. Mesosphere
4. Outer Core
5. Inner Core

11. LITHOSPHERE:
This is the “crunchy” layer of the Earth.
Location: crust and upper mantle
Thickness: km
Lithosphere = tectonic plates

12. ASTHENOSPHERE:
Location: the middle mantle
Soft – can bend like plastic
Lithosphere floats on this layer (like jello)
Thickness: 250 km

13. MESOSPHERE:
Location: the lower mantle
Thickness: 2,550 km

14. Outer Core: Thickness: 2,300 km
Composition: LIQUID iron (with some nickel)
Thickness: 2,300 km

15. Inner Core:
Composition: SOLID iron and a little nickel
Solid because of increased pressure
Thickness: 1,220 km thick

16. Lithosphere Asthenosphere Mesosphere CRUST MANTLE OUTER CORE
INNER CORE

17. Density, Pressure, and Temperature
Moving towards the center of the earth:
Density increases
Pressure increases
Temperature increases

18. In Review:
What are the 3 main layers of the Earth?
Crust, Mantle, Core
Which layer is the least dense?
Crust
Which core layer is solid iron and nickel?
Inner core
What is the name given to the “crunchy” layer of the crust and uppermost part of the mantle?
Lithosphere
5. The motion in this layer is the reason Earth has a magnetic field.
Outer core