| A | B |
|---|
| crust | Earth's outermost and thinnest layer |
| mantle | middle and thickest layer of Earth |
| core | innermost layer of Earth |
| plates | continent-sized slabs of the crust and upper mantle |
| earthquake | vibration or shaking of Earth's crust |
| fault | break in the crust where most earthquakes occur |
| focus | point underground where an earthquake first takes place |
| epicenter | point on the surface that is right above the focus |
| seismograph | an instrument that records earthquake waves |
| volcano | mountain that forms when magma flows to Earth's surface |
| magma | melted rock inside Earth |
| lava | melted rock that reaches Earth's surface |
| vent | rocky tube that allows magma to rise to the surface |
| magma chamber | an underground pool that holds hot magma |
| crater | a large, bowl-shaped depression |
