1. Journey to Center of the Earth

2. Draw a model of the inside of earth
On loose leaf paper Art supplies available

3. THE LAYERS What was right about your model?
What was wrong about your model?

4. CRUST What we know? Rocky- mainly silicates (quartz, feldspar) Brittle
Broken into pieces (plates)
Continental- granite (less dense)- thicker
Ocean- basalt (more dense)-thinner

6. CRUST
How do we know it?
Direct samples ( drill cores)
sonograms

7. Drill cores
Deepest 12 km
Tried to reach Moho
failed

8. drilling attempts to the Moho
Russia km
7 miles
$100 million 190° C
US km

9. Drilling program
April drilled 1416 meters
Gabbro rocks
Near Mid-Atlantic Ridge
$1.5 billion budget

10. Lithosphere
Rigid- crust + upper mantle
Makes up Earth’s plates

11. Asthenosphere
Solid rocks that flow
Plates “float” on asthenosphere

12. MANTLE What we know? Solid that flows (plasticity)
magma
Composed of iron, magnesium (olivine)
Has convection currents

13. Mantle

14. MANTLE How do we know it? S waves travel through mantle
Volcanoes give us a “peek”

15. OUTER CORE What we know? Liquid iron How we know it?
S-waves do not travel through outer core
Magnetic field

16. Seismic waves P waves S waves Travel through liquids and solids
Travel slower thru liquids than solids
S waves
Do NOT travel through
LIQUIDS

17. INNER CORE What we know? Solid iron How we know it? P-waves speed up
Study meteorites