1. Crust
Earth's outer layer; includes the rock of the ocean floor and large areas of land

2. The thickest layer of Earth; found just below the crust
Mantle
The thickest layer of Earth; found just below the crust
                                       

3. Core
The dense center of Earth; a ball made mostly of two metals, iron and nickel                                        

4. Continent-sized slab of Earth's crust and upper mantle
Plates
Continent-sized slab of Earth's crust and upper mantle

5. A vibration, or shaking, of Earth's crust
earthquake
A vibration, or shaking, of Earth's crust

6. A break in Earth's crust along which rocks move .
fault
A break in Earth's crust along which rocks move .

7. focus
The point underground where the movement of an earthquake first took place

8. epicenter
The point on the surface of Earth that is right above the focus of an earthquake.

9. An instrument that records earthquake waves .
seismograph
An instrument that records earthquake waves .

10. volcano
A mountain that forms when red-hot melted rock flows through a crack onto Earth's surface.

11. Melted rock inside Earth.
magma
Melted rock inside Earth.

12. A melted rock that reaches Earth's surface
lava
A melted rock that reaches Earth's surface

13. vent
The rocky tube in a volcano through which magma rises toward the surface.

14. An underground pool below a volcano that holds magma
magma chamber
An underground pool below a volcano that holds magma

15. crater
A large basin formed at the top of a volcano when it falls in on itself.