Plate Tectonics

2. The theory that the lithosphere is broken up into large plates that move and then rejoin; considered the unifying theory of geology.
3. A plate boundary where two plates move toward each other.
5. A weak spot in the middle of a tectonic plate where magma surfaces; forms a volcano.
8. A plate boundary where two plates move past each other in opposite directions.
9. The parts of Earth's crust that form the continents.
11. A plate boundary where two plates move away from each other.
13. A dense sphere of solid iron and nickel at the center of Earth.
14. The idea that continents have moved and are still moving slowly across the Earth's surface.
16. Any of the many processes (such as eruptions and lava flows) in which gas, lava, and ash are pushed out on the surface of Earth.
17. A break in the earth's crust.
18. The region where two tectonic plates are in contact.
20. one of the seven large landmasses on the earth.
22. The "plastic" layer of the earth between the crust and the core.
23. Earth's crust located under the ocean.
24. The rising of regions of the Earth's crust to higher elevations.
25. A layer of liquid iron and nickel that surrounds the inner core of Earth.

1. The process that creates new sea floor as plates move away from each other at the mid-ocean ridges.
4. the upper layer of the earth's mantle, below the lithosphere, in which there is relatively low resistance to plastic flow and convection is thought to occur.
6. A series of volcanoes formed at a subduction zone.
7. The thin and solid outermost layer of the Earth above the mantle.
10. The region where oceanic plates sink down into the asthenosphere.
12. A block of lithosphere that consists of the crust and the rigid, outermost part of the mantle.
15. A deep valley that forms where two plates move apart.
19. A rigid layer made up of the uppermost part of the mantle and the crust.
21. The shaking that results from the movement of rock beneath Earth's surface.