Plate Tectonics

3. core solid, dense center of the Earth
5. outermost layer of the Earth
6. a pulling force
7. drift theory that continents drift apart
10. a break in the Earth's crust
12. outermost, rigid layer of the Earth
16. spreading new lithosphere is created here
17. zone a region where a an oceanic plate sinks down into the athenosphere
18. current The pathway along which energy travels through a fluid.
20. trench linear depression of the sea floor caused by the subduction of one plate under another.

1. boundary between two colliding plates
2. boundary between two plates moving away from each other
4. soft layer of the mantle
8. layer between the crust and the core
9. boundary between two plates that are sliding past each other
11. a squeezing force
13. plate piece of the lithosphere that moves on the asthenosphere
14. ridge A chain of mountains on the ocean floor where the sea floor is spreading.
15. the bending of rock layers
19. core liquid layer of the Earth's core