Plate tectonics

4. A break or crack in the Earth's lithosphere along which rocks move
5. the name of the single landmass that broke apart about 225 million years ago
6. The process by which oceanic crust sinks beneath a deep-ocean trench and back into the mantle at a convergent plate boundary
8. a sudden and violent shaking of the ground, sometimes causing great destruction, as a result of movements within the earth's crust or volcanic action.
9. The layer of rock that forms the Earth's outer surface
10. a mountain or hill, typically conical, 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.
11. A deep valley where two plates move apart
14. Dense ball of solid material at the center of he Earth
15. A layer of molten iron and nickel that surrounds the inner core of the Earth
16. A soft layer of the mantle on which the lithosphere floats

1. A plate boundary where two plates move away from each other
2. Thickest layer of the Earth; it consists of two layers - the lithosphere and the asthenosphere
3. German Scientist who developed the Theory of the Continental Drift in 1912.
7. A plate boundary where two plates grind against each other, moving it different directions
12. A rigid layer made up of the uppermost part of the mantle and the crust
13. A deep canyon on the ocean floor