Plate Tectonics

6. Idea that continents moved across the surface of Earth.
9. The addition of new oceanic crust from mid-ocean ridges.
10. A trace of an organism that has been preserved.
11. A German scientist that had the idea of continental drift.
14. These form when two plates collide and neither are dense enough to sink.
16. The process oceanic crust sinks back into the mantle.
17. Where pieces of Earth's crust move away from each other on land.
18. Where plates move apart from each other.
19. Where part of the oceanic crust sinks back into the mantle.
20. A break in Earth’s crust where rocks slid past each other.

1. Forms only when molten hardens quickly under water.
2. Forms chains of mountains that rise upwards from the ocean floor.
3. A natural disaster that occurs when plates suddenly slip on their boundary.
4. The last supercontinent.
5. Where plates move towards each other.
7. Combined knowledge of sea-floor spreading, Earth’s plates, and plate motions.
8. Where plates slip past each other.
12. Where Earth's plates meet, there are three different types.
13. Pieces of Earth's lithosphere separated by cracks.
15. A device that uses sound to measure the distance to an object.