| A | B |
|---|
| volcano | a weak spot in the crust where magma comes to the surface |
| magma | molten rock underground |
| lava | molten rock on Earth's surface |
| shield volcano | volcanic landform that is a low, gently sloping hill |
| cinder cone volcano | volcanic landform that is made from solid material that has erupted explosively |
| composite volcano | volcanic landform made from alternating layers of lava and solid material |
| Ring of Fire | area with many volcanoes and frequent seismic activity |
| hot spot | the Hawaiian Islands are an example of this. |
| geothermal area | area where magma is close to the surface but has not broken through the crust |
| Pacific Ocean | The Ring of Fire may be found around its edges |
| island arcs | chains of islands that form at an oceanic subduction zone |
| dormant volcano | volcano that has not erupted in recent years but may erupt at any time |
| extinct volcano | volcano that has not erupted in many years and is not likely to erupt again |
| caldera | a crater that has become enlarged and may have filled with water |
| active volcano | volcano that has erupted recently or may erupt soon |
