1. Plate Tectonics
Composition of Earth

2. Chemical Layers of Earth

3. Two Types of Crust Oceanic 5-10 km dense rock basalt common
Continental
30-50 km
lighter rock
granite common
Oceanic
3-6 mi deep
30-50 km -> 20-30mi

4. How thin is thin? Earth is about 40,000 km circumference
In kilometers 10km = 6 mi.
If Earth was a basketball, the crust would be a single sheet of paper.
Earth is about 40,000 km circumference

5. Mantle
~600 to 3000 km
Slow circulation – convection currents!

6. Outer Core ~3000 to 5200 km iron and nickel low viscosity (liquid)

7. Inner Core ~5200 km solid ball massive pressure mostly iron

8. Physical layers of Earth
Lithosphere
Asthenosphere
Mesosphere
Outer core
Inner core

9. What’s the lithosphere?
the rigid, outermost shell
it is the crust AND the upper portion of the mantle that is hard
broken into tectonic plates
brittle

10. Mesosphere higher pressure causes denser, more rigid structure
(Not to be confused with atmospheric mesosphere layer!)

11. And the asthenosphere? deeper, weaker, and hotter than lithosphere
part of the upper mantle
asthenosphere rock is ductile (deforms like softer plastic)
viscous
Viscous: Having a thick, sticky consistency between solid and liquid

12. What did you learn?
How are the layers different in temperature, pressure, and composition?