2. PREM = Preliminary Reference Earth Model

3. So what is the Earth’s interior made of? Look for rocks at surface with Vp ~ 8 km/s and density ~ 3.5 km/s

4. Peridotite

5. Eclogite

6. Does peridotite or eclogite fit the enterior?

7. Need high pressure experiments Principle is to generally reduce surface area

8. Multi-anvil cell 25 GPa (700 km) and 2500 K Sample ~1mm

9. Diamond anvil cell 350 GPa or so (centre of Earth) Very small sample (i.e. 0.1 mm)

10. Shock experiments Very small samples very little time 1 TP (inside of Jupiter)

11. Does peridotite or eclogite fit the enterior?

12.  = olivine  = wadsleyite  = ringwoodite 1 kbar ~ 3 km 1 GPa ~ 30 km

14. Short dashed = observed Long dashed = (Mg 0.9 Fe 0.1 ) 2 SiO 4 at1700 K Solid line = (Mg 0.9 Fe 0.1 ) 2 SiO 4 at 2000 K Bina & Wood (1987)

17. Seismic tomography

18. CAT Scan (uses x-rays)