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Chapter # Section 2
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Question | Answer |
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Silica | material that is formed from the elements oxygen and silicon. |
Magma Chamber | beneath a volcano, magma collects in a pocket. |
pipe | long tube in the ground that connects the magma chamber to earth's surface. |
lava flow | area covered by lava as it pours out of a vent. |
crater | bowl-shaped area that may form at the top of a volcano's central vent. |
What helps you determine whether the volcano is quiet or explosive? | the silica content of magma. |
Pyroclastic flow | occurs when an explosive eruption hurls out ash, cinders, and bombs as well as gases. |
Active Volcano | "alive", shows signs that may erupt again in the future. |
Dormant Volcano | "sleeping", like a sleeping bear, may awaken in the future and become active. |
Extinct Volcano | "dead", not likely to erupt ever again. |
Hot spring | forms when groundwater heated by a nearby body of magma rises to the surface and collects in a natural pool. |
Geyser | fountain of water and steam that erupts from the ground. |
Geothermal Energy | water heated by magma can provide a clean reliable energy source. |
Although quiet and explosive eruptions involve different volcano hazards, Can both of them cause damage as far from the crater's rim? | Yes |
What texture is magma if it is high on silica and what color? What type of rock does it turn into when the lava cools? | Really sticky and slow-moving and makes light-colored lava. When is cools, it forms rock rhyolite which has the same composition as granite. |
What texture is magma if it is low in silica? What type of rock does it form when the lava cools? | flows readily and produces dark-colored magma. When it cools, basalt is formed. |
What happens to the gases when a volcano erupts? | They dissolve and escape from the magma. |
How does magma reach Earth's surface? | Forms in the asthenosphere and is put under great pressure. Because magma is less dense then the surrounding solid material, magma flows up through any cracks or openings in the rock above. It rises till it reaches Earth's surface. |
What happens to the pressure as it gets closer to Earth's surface? | The pressure decreases. |
What is the difference between quiet eruption and explosive eruption? | quiet- thinner, runny, gases dissolve gently, less silica explosive- thick, sticky, erupts explosively, lot of silica, hard for gases to escape, strong force when erupts |