Plate Tectonics

2. The relatively thick part of the Earth’s crust that forms the large landmasses, typically less dense and older than oceanic crust.
6. A layer of molten iron and nickel that surrounds the inner core of Earth.
7. The hypothesis that the continents slowly move across Earth’s surface.
10. The layer of rock that forms Earth’s outer surface.
12. The soft layer of the mantle on which the lithosphere floats.
13. A layer of hot, solid material between Earth’s crust and core.
15. The process by which molten material adds new oceanic crust to the ocean floor.

1. A dense sphere to solid iron and nickel in the center of the Earth.
3. A weak spot in the crust where magma had come to the surface.
4. A thin layer of crust that under lies the ocean basins and is usually younger and denser than the continental crust.
5. The movement of a fluid, caused by differences in temperature, that transfers heat from one part of a fluid to another.
8. A giant wave caused by an earthquake in the ocean floor.
9. A break or crack in Earth's lithosphere along which the rocks move.
11. The shaking that results from the movement of rock beneath Earth's surface.
14. A rigid layer made up of the uppermost part of the mantle and the crust. One of four spheres into which scientists divide Earth.