| A | B |
|---|
| volcano | an opening in Earth's surface that forms a mountain built of lava |
| vent | an opening in Earth's surface in which lava can flow |
| crater | steep walled depression at the top of a volcanic vent |
| Pacific Ring of Fire | an area where volcanoes and earthquakes are common due to tectonic plate movement |
| hot spot | areas that are hotter than surrounding areas, forming melted rock that rises toward the crust |
| geothermal energy | thermal energy from inside the Earth |
| HDR | Hot dry rock |
| shield volcano | a broad volcano, gentle sloping sides, built of basaltic lava |
| tephra | lava blasted into the air by violent eruptions. |
| cinder cone | a volcano made of tephra piled up in a steep cone |
| composite volcano | volcano built of silica rich lava and tephra layers |
| batholith | largest intrusive igneous rock bodies formed when magma cools and stops rising to the surface |
| dike | intrusive igneous rock body formed by magma squeezed into vertical cracks, solidifies underground |
| sill | intrusive igneous rock body formed when magma is squeezed into horizonal cracks |
| volcanic neck | a solid igneous core of a vent that remains after the outer layers of lava and tephra have been eroded away |
| caldera | large opening formed at the top of a volcano when a crater collapses into a vent |
| Aa | lava that is rough and jagged |
| Pahoehoe | lava that is smooth |
| Volcanic bombs | ejections from a volcano that are larger than 64mm |
| ash | 2mm ejections from volcanoes |
| Formed when magma enters a vertical crack and hardens | dike |
| created when magma in a sill pushes up to form a rock dome | lacolith |
| formed when layers of lava and ash erupt and build up | volcano |
| used to spin turbines that run generators when geothermal energy is changed into electricity | steam |
| example of a composite volcano | Mt. St. Helens |
| an example of a volcanic neck | Ship Rock |
| world's most active volcano | Kilauea |
| lava | molten rock that flows from volcanoes |
| hot spot | result of an unusually hot area at the boundary between the Earth's mantle and core |
| granitic | light-colored, silica-rich igneous rock |
| basaltic | dense, dark-colored igneous rock |
| magma | hot, melted rock material beneath Earth's surface |
| igneous rock | rock formed when magma or lava cools and hardens |
