| A | B |
|---|
| magma | molten mixture of rock-forming substances, gases and water from the mantle |
| lava | magma that has reached the surface |
| a volcanic eruption is | the gases dissolved in magma rush out, carrying the magma with them |
| magma chamber | magma collects inside a pocket within the volcanoe |
| pipe | a long tube in the ground that connects the magma chamber to the Earth's surface |
| lava flow | an area covered by lava as it pours out of a vent |
| crater | bowl-shaped area that may form at the top of a volcano around the volcano's central vent |
| silica | a material that is formed from the elements oxygen and silicon |
| Pahoehoe | fast moving, hot lava |
| aa | lava that is cooler and slower moving |
| pyroclastic flow | an explosive eruption hurls out ash, cinders, and bombs as well as gases |
| active | is erupting or shows signs that it may erupt in the near future |
| dormant | "sleeping" stage, where as it might erupt in the future |
| extinct | unlikely to erupt again |
| hot spring | groundwater has heated by a nearby body of magma rises to the surface and collects in a natural pool |
| geothermal energy | water heated by magma can provide this type of energy |
| hot spots | places where magma from deep within the mantle melts through the crust above it |
| Ring of Fire | one major belt formed by the many volcanoes that rim the Pacific Ocean |
| volcano | a weak spot in the crust where molten material from the mantle comes to the surface |
| magma | the molten mixture of rock-forming materials, gases, and water |
| lava | liquid magma that reaches the surface |
