Earth's Tectonic Plates

1. A large chunk of lithosphere.
7. Were once joined and the moved apart.
11. Plates move by _____ spreading.
12. Plate move around Earth's surface at a rate of a few ____ a year.
13. ____ material is heather above the core.
14. Causes the plates to move within Earth's mantle.
16. The point on Earth's surface directly above the place where an earthquake occurs.

2. ____ polar wonder is a phenomenon that the magnetic pole has seemed to moved.
3. The oldest continental crust is about 4 ___ yrs old.
4. Some rocks contain little ____.
5. ___ is divided into plates.
6. Rocks on the seafloor that were at the mid-ocean ridges.
8. A device capable of measuring the magnetic field.
9. The magnetic ___ reverses from time to time.
10. Noticed that South America and Africa appeared to fit together like a puzzle.
15. Measures the ground shaking.