Across
- 3. measures small changes in magnetic fields
- 4. a theory that earth's outer layer is made up of plates that move around the surface relative to each other
- 9. the motion exerted by a cold, dense plate sinking into the mantle at trenches
- 10. a change in Earth's magnetic field
- 11. when one plate is forced under the other
- 12. a tectonic boundary where two plate are moving toward each other
- 13. a steep lowland between several mountain ranges
Down
- 1. the study of the magnetic record in rocks
- 2. a supercontinent that included almost all landmasses on Earth
- 5. a mechanism for plate motion in plate tectonics
- 6. a line that connects points on a line that have the same age
- 7. a new ocean crust is formed at ocean ridges and destroyed at deep-sea trenches
- 8. the movement of earth's continents relating to each other