Question | Answer |
Volcano | A weak spot in the crust where magma comes to the surface |
Magma | Mixture of melted rock and gases |
Lava | magma when it reaches the surface |
Ring of fire | major volcanic area formed by many volcanoes around the Pacific Ocean |
Volcanoes on diverging plate bounderies | volcanoes form along a mid-ocean ridge |
Island arc | a string of islands created by converging plates when one plate is pushed under another. |
Hot spot volcanoes | an area no where near a plate boundary where magma melts through the crust. |
viscosity of magma | magma can either be thin and runny (low viscosity) or thick and chunky (high viscosity)
The more silica ( silicon + oxygen) magma contains, the thicker it is |
types of volcanic eruptions | eruptions can be quiet or explosive depending on the volcanoes magma |
quiet | thin , runny lava oozes quietly from a vent
Pahoehoe-which is fast moving, thin lava
aa-which is slower, thicker, cooler lava |
explosive volcanic eruptios | magma is thick and sticky
magma becomes trapped in volcanoes pipe, pressure builds
this creates bombs,ash,and lava called a pyroclastic flow |
stages of a volcano | active is a volcano that is erupting or shoes signs that it may erupt in the near future
dormat, or sleeping volcano may become active
extict, or dead volcano is unlikely to erupt again |
other types of volcanic activity | hot springs forms |
explosive volcanic eruptios | magma is thick and sticky
magma becomes trapped in volcanoes pipe, pressure builds
this creates bombs,ash,and lava called a pyroclastic flow |
stages of a volcano | active is a volcano that is erupting or shoes signs that it may erupt in the near future
dormat, or sleeping volcano may become active
extict, or dead volcano is unlikely to erupt again |
other types of volcanic activity | hot springs forms when groundwater heated by magma rises to the surface and collects in a natural pool
Geyser is a fountain of water and steam that erupts from the ground |