| A | B |
|---|
| aa | a slow-moving type of lava that hardens to form rough chunks; cooler than pahoehoe |
| active | said of a volcano that is erupting or has shown signs of erupting in the near future |
| batholith | a mass of rock formed when a large body of magma cooled inside the crust |
| caldera | the large hole at the top of a volcano formed when the roof of a volcano's magma chamber collapses |
| cinder cone | a steep, cone-shaped hill/mountain made of volcanic ash, cinders, and bombs piled up around a volcano's opening |
| composite volcano | a tall, cone-shaped mountain in which layers of lava alternate with layers of ash and other volcanic materials |
| crater | a bowl-shaped area that forms around a volcano's central opening |
| dike | a slab of volcanic rock formed when magma FORCES ACROSS rock layers |
| dormant | said of a volcano that does not show signs of erupting in the near future |
| extinct | word used to describe a volcano that is unlikely to erupt again |
| geothermal energy | heat energy in Earth's interior from water or steam that has been heated by magma |
| geyser | a type of hot spring that builds up pressure underground and erupts at regular intervals as a fountain of water and steam |
| lava flow | the area covered by lava as it pours out of a volcano's vent |
| magma chamber | the pocket beneath a volcano where magma collects |
| pahoehoe | a hot, fast-moving type of lava that hardens to form smooth, ropelike coils |
| pipe | a long tube through which magma moves from the magma chamber to Earth's surface |
| psyroclastic flow | the expulsion of ash, cinders, bombs, and gases during an explosive volcanic eruption |
| shield vocano | a wide, gently sloping mountain made of layers of lava and formed by quiet eruptions |
| silica | found in magma it is a material that is formed from the elements oxygen and silicon |
| sill | a slab of volcanic rock formed when magma SQUEEZES BETWEEN rock layers |
| vent | the opening through which molten rock and gas leave a volcano |
| volcanic neck | a deposit of hardened magma in a volcano's pipe |
