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Volcanic Activity
Inside Earth: Chapter Three, Section Two
Term | Definition |
---|---|
magma chamber | the pocket beneath a volcano where magma collects. |
pipe | a long tube through which magma moves from the magma chamber to Earth's surface. |
vent | the opening through which molten rock and gas leave a volcano. |
lava flow | the area covered by lava as it pours out of a volcano's vent. |
crater | a bowl-shaped area that forms around a volcano's central opening. |
silica | a material that is formed from the elements oxygen and silicon; silica is found in magma. |
pahoehoe | a hot, fast-moving type of lava that hardens to form smooth, replace coils. |
aa | a slow-moving type of lava that hardens to form rough chunks; cooler than pahoehoe |
pyroclastic flow | the expulsion of ash, cinders, bombs, and gases during an explosive volcanic eruption. |
active | said of a volcano that is erupting or shows signs of erupting in the near future. |
dormant | said of a volcano that does not show signs of erupting in the near future. |
extinct | said of a volcano that is unlikely to erupt again. |
hot spring | a pool formed by groundwater that has risen to the surface after being heated by a nearby body of magma. |
geyser | a fountain of water and steam that builds up pressure underground and erupts at regular intervals. |
geothermal energy | energy from water or steam that has been heated from magma. |
quiet eruption | occurs when a volcano's magma flows easily. |
explosive eruption | occurs when a volcano's magma is thick and sticky and builds up in the pipe. |