| A | B |
|---|
| Viscosity | a substance's resistance to flow - decreases as temperature increases |
| vent | the opening of a volcano |
| crater | the bowl shaped depression at the top of a volcano |
| caldera | occurs when the crater caves in, blocking the vent of a volcano |
| tephra | rock fragments thrown into the air during a volcanic eruption |
| pyroclastic flow | rapidly moving volcanic material such as ash, dust, gas, or even lava |
| hot spot | unusually hot regions of Earth's mantle where magma rises to the surface |
| cone | the shape of a volcano |
| shield volcano | the largest, and least dangerous type of volcano |
| cinder cone volcano | the smallest type of volcano that contains very viscous lava |
| composite volcano | the most dangerous type of volcano - highly explosive |
