1. What’s in there? How do we know its there? Why do we even care?
Earth’s Interior
What’s in there?
How do we know its there?
Why do we even care?

2. Studying the Earth’s Interior
Seismic Wave Studies
allow the scientists to compare different regions
measure refraction
measure reflection
measure velocity changes
measure absorption
P-waves –move parallel to the direction of their propagation like sound waves
S-waves – move perpendicular to the direction of their propagation

3. Zones of the Earth Crust outermost layer solid rock Moho
thin interface
crust/mantle
rocks denser below
Mantle
mostly solid
thickest zone
80% of volume

4. Mantle Pieces Lithosphere crust + rigid mantle sections - “plates”
Athenosphere
wave velocity 
“plastic”
partially molten
melting point/temperature intersect
Stiffer Mantle

5. Core Regions Outer Core liquid how waves refract in shadow zones
how wave reflect off inner core
Inner Core
solid
due to great pressure

6. Inner Core
note pressure graph

7. Earth’s Crust Continental Crust (20-70 km) thickest by mountains
less dense (2.7 g/cm3)
granitic rocks
Oceanic Crust (7-10 km)
more dense (3.0 g/cm3)
basaltic rocks

8. Earth’s Interior Mantle (1000-3000 km) less dense (3.3 – 5.5 g/cm3)
Outer Core ( km)
more dense (9.9 – 12.1 g/cm3)
iron
Inner Core (5000 – 6000 km)
most dense (12.7 – 13.0 g/cm3)
iron and nickel