| A | B |
|---|
| Active | A volcano that has shown recent activity. |
| Dormant | A volcano that is inactive. |
| Geothermal | The internal heat of the earth. |
| Geyser | A hot spring that sends up jets of water and steam into the air. |
| Hot Spring | A spring warmer than 98 degrees, being heated by hot or molten rock. |
| Magma | Molten material beneath or within the earth's crust. |
| Ring of Fire | The linear zone of seismic and volcanic activity. |
| Crust | The outermost layer of the earth. |
| Mantle | The layer of the earth beneath the crust. |
| Tectonic Plates | Plates that make up the surface of the earth. |
| Volcanologist | A person who studies volcanoes. |
| Shield Volcano | A broad volcano built up from nonexplosive eruptions. |
| Composite Volcano | A large steep volcano built up from layers of lava, ash, and cinders. |
| Cinder Cone | A small volcano made up of ash and cinders. |
