INTERIOR OF THE EARTH

A more complete set of notes will follow - here is the outline.

1. Know Earth's concentric layers and their major physical properties.
2. How do seismic waves show liquid outer core and solid inner core?
3. Layers are defined by changes in wave velocities at discontinuities.
4. Density and elasticity control refraction and reflection of waves.
5. Why do we think the core is Fe, Ni with minor S, Si, ...?
6. Oceanic vs. Continental crust: properties, composition, density.
7. How was the "Moho" discovered? What is its significance?
8. Why must the surface geothermal gradient decrease with depth? What is the estimated core temperature?
9. Heat flow is continuous; what is the source of this heat?
10. Understand the principle of isostacy - how does this reflect behavior of the crust?
11. Why does ocean and continental crust "float" at different elevations?
12. What is a gravity anomaly? Why do we care?
13. Where does the Earth's magnetic field come from?
14. What is (and what use is) magnetic declination and inclination?
15. What are magnetic anomalies? Has the Earth's field stayed constant?