1. Comparing the Layers of Earth
S6E5.a.

2. Earth’s layers are compared by:
Temperature
Density
(the thickness or depth of the layer)
Composition
What each layer is made of or how it is described

3. Which is the outermost layer?
THE CRUST
Temperature:
Temp of the air outside to 1600 °F
Density: 5km – 70km thick

4. The Crust: What’s it made of?
2 types of crust:
Oceanic – mostly basalt rocks
The thinnest crust
Continental – mostly granite rocks
The thicker crust

5. What do you find on Earth’s crust?
Rocks
Mountains
Soil
Water
What else???

6. Where the Crust ends and the Mantle begins is an area called the MOHO Discontinuity.
1909: Andrija Mohorovicic discovers the moho discontinuity, which is the boundary between Earth’s crust and mantle.

7. Next is the Mantle… Mantle Temperature range: From 1600 °F to 6700 °F
Density of the WHOLE Mantle = 2867 km!
Let’s break it apart!

8. The Mantle Made of 3 distinct areas: Lithosphere Asthenosphere
Lower Mantle

9. Mantle’s Lithosphere Density = approx 100 km Composition: Rigid layer
Rocky like Crust
“Lithos” means “Stone”
Unique? Made up by part of the Crust!

10. Mantle’s Asthenosphere
Density = 300 km
Composition:
Plastic-like
Solid, but softer
“Asthenes” means “weak”
Unique? Makes the plates move! Because it’s slowly flowing.

11. Lower Mantle
Density = 2467 km
Composition:
Solid
Unique? Semi-rigid

12.  Gutenberg Discontinuity
Where the Mantle ends and the Outer Core begins is an area called the GUTENBERG DISCONTINUITY

13. Outer Core Temperature = 6700 °F to 7800 °F Density = 2266 km
Composition:
Liquid, Molten Metal
(Fe & Ni)

14. What makes the Outer Core unique?
Creates Earth’s magnetic field
High temps from the formation of the planet keep the Iron (Fe) & Nickel (Ni) liquid

15. Inner Core Temperature = 7800 °F to 13000 °F HOTTEST LAYER!!!
Density = 1216 km
Composition:
Dense, solid metal ball of Fe & Ni!

16. What’s unique about the Inner Core?
Extreme pressure squeezes the atoms of the Fe & Ni so much, they cannot spread out!
Stays solid!