science vocab

4. A rigid layer made up of the uppermost part of the mantle and the crust
10. A deep valley along the ocean floor through which oceanic crust slowly sinks towards the mantle
13. A deep canyon on the ocean floor
14. A soft layer of the mantle on which the lithosphere floats
15. The name of the single landmass that broke apart about 225 million years ago
16. A break or crack in the Earth's lithosphere along which rocks move

1. A deep valley where two plates move apart
2. The layer of rock that forms the Earth's outer surface
3. Cause the plates to move; between the lithosphere and the asthenosphere
5. A plate boundary where two plates move toward each other
6. The undersea mountain mountain chain where new ocean floor is produced; a divergent plate boundary
7. A layer of molten iron and nickel that surrounds the inner core of the Earth
8. Dense ball of solid material at the center of the Earth
9. The process by which oceanic crust sinks beneath a deep-ocean trench and back into the mantle at a convergent plate boundary
11. Alfred Wegener's hypothesis that the continents were once one huge land mass but have since then drifted apart
12. thickest layer of the Earth; it consists of two layers - the lithosphere and the asthenosphere