Across
- 4. How scientists study the inside of Earth since we can’t drill down that far
- 6. When plates move away from each other
- 8. When oceanic crust sinks beneath a deep-ocean trench and back into the mantle
- 10. Measure of how much mass there is in an object
- 11. When plates come together
- 12. A break in Earth’s crust where rocks slipped past each other
- 14. When molten material is added to make new oceanic crust
- 16. Theory of how the continents spread away from each other
- 19. The theory that Earth’s plates are in a slow, constant motion
- 20. The remains of a prehistoric organism
Down
- 1. Scientist that came up with the theory of continental drift
- 2. What scientists use to explore the ocean floor
- 3. Valley along the ocean floor where oceanic crust sinks into the mantle
- 5. Where seafloor spreading begins
- 7. When pieces of Earth’s crust diverges on land
- 9. When plates slip past each other
- 13. Causes the plates to move
- 15. 3rd layer of Earth that is very hot, yet solid where convection currents are
- 17. Supercontinent that existed around 300 million years ago
- 18. Produced when 2 continental plates collide