Across
- 4. device that uses sound waves to measure distance
- 5. Wegner was a _______
- 7. when the ocean floor sinks back into the mantle
- 9. pieces of the earth separated by cracks
- 10. a deep valley
- 13. the ocean that is expanding
- 16. heat transferred by the movement of fluid
- 17. scientist that came up with the idea of pangea
- 18. breaks in earths crust
Down
- 1. a super-continent
- 2. the measure of how much mass is in a given volume
- 3. transfer of energy through rays
- 6. plates come together
- 8. when the Plates are in slow constant motion its called
- 11. ancient item preserved in rock
- 12. large land masses that make up earth
- 14. plates slip past each other
- 15. plates move apart