Plate Tectonics

3. The joining of all the landmasses on Earth; it means "all lands" in Greek
6. The edges of plates
10. The layer of rigid rock that includes all of the crust and the upper portion of the mantle
11. A long, narrow, steep-sided depression in the ocean bottom.
12. Cracks in the Earth’s crust
14. Places where two plates grind past each other
15. The sinking of older, more dense crust
16. A German astronomer and meteorologist who created the “continental drift” theory
19. Pieces of the earth's lithosphere
20. A process in which new ocean floor is created from molten material rising in margins between plates or ridges and spreading out
21. A depression of the Earth’s surface in which an ocean lies

1. A large area in which plates are moving away from each other, forming several fractures and faults
2. A sudden and violent shaking of the ground
4. A layer of solid rock that behaves like a fluid
5. Places where two plates come together
7. Separating plates beneath the ocean; the longest chain of mountains (or volcanoes) in the world; circles the Earth
8. Heat that circulates in the Earth, causing magma to flow and tectonic plates to shift
9. Places where two plates move apart or divide
13. A continental transform fault that extends about 800 miles through California
17. A mountain or hill having a crater or vent through which lava, rock fragments, hot vapor, and gas are being or have been erupted from the earth's crust
18. A belt of volcanoes and frequent seismic activity around the edges of the Pacific Ocean