| A | B |
|---|
| gases in magma | What increases the pressure of the molten rock underground leading to a volcanic eruption? |
| magma chamber | the pocket beneath a volcano where magma collects |
| vent | the opening through which molten rock and gas leave a volcano |
| pipe | a long tube through which magma moves from the magma chamber to Earth's surface |
| crater | a bowl-shaped area that forms around a volcano's central opening |
| lava flow | the area covered by lava as it pours out of a volcano's vent |
| silica | material in magma formed from the elements oxygen & silicon |
| the amount of silica it contains | What determines how easily magma flows? |
| the amount of gas in the magma, how thick or thin the magma is, its temperature, & its silica content | What 4 factors determine the force of a volcanic eruption |
| quiet eruption | What type of eruption involves lava flows? |
| explosive eruption | What type of eruption blasts out cinders, ash, and bombs? |
| 2 types of lava | What are pahoehoe & aa? |
| pyroclastic flow | What do we call the violent explosion of ash, cinders, bombs, & gases? |
| active | What do we call a volcano that is erupting or has shown signs that it may erupt in the near future? |
| extinct | What do we call a dead volcano--one that is unlikely to erupt again? |
| dormant | What do we call a sleeping volcano--one that is expected to awaken & become active? |
| geothermal energy | heat energy in Earth's interior from water or steam that has been heated by magma |
| hot spring | a pool formed by groundwater that has risen to the surface after being heated by a nearby body of magma |
| geyser | a type of hot spring that builds up pressure underground & erupts at regular intervals as a fountain of water & steam |
