plate tectonics
Across
- 1. a mountain that erupts
- 8. earth's plates that are in slow constant motion
- 10. a process that adds new material to the ocean floor
- 11. german scientist who discovered that the continents were together at one point
- 14. a supercontinent that existed 2 million years ago
- 15. heat transfer from air currents
- 17. plates come together
- 18. plates slip past eachother
- 19. deep underwater canyons
- 20. pieces of earth separated by cracks
Down
- 2. a process where the ocean floor sinks in the mantle
- 3. forms when pieces of earth's crust diverge on land
- 4. a layer of hot rock
- 5. underwater ocean ranges
- 6. any trace of an ancient organism preserved in rock
- 7. the uppermost part of the mantle
- 9. plates collide
- 12. breaks in the earth's crust
- 13. a large body of water
- 15. - an idea that continents slowly move
- 16. how much mass there is in a given amount of volume