Volcanourrr

• Types of volcano:

  Active

  Dormant

  Extinct
• Active volcanoes. Has a recent history of eruptions
• Dormant volcanoes. Volcanoes that have not erupted for a very long time, but may erupt in the future
• Extinct volcanoes. Are not expected to erupt in the future
• Viscosity. The ability and the resistence of the magma to flow.
• Viscosity depends on the composition of the magma  

  True
• High temperature 


  Low viscosity
• Low temperature 


  High viscosity
• High silica


  High viscosity
• Low silica 


  Low viscosity
• High viscosity. Viscuos, thicker and features slow moving magma
• Highest viscosity. Magma does not move at all due to it's viscosity
• Lowest viscosity. Thinner and features fast moving magma
• Phreatic. A type of eruption, and is a stream-driven eruption that is caused by the interaction between magma and water, features ash columns, and may be an onset on larger eruption
• Plinian. Largest and the most violent type of eruption, its eruption can reach up to 50km (stratosphere) and is capable of emptying the magma chamber, and becomes inactive after it's eruption
• Hawaiin. Very fluid, and basaltic fluid, and forms rivers from the vent
• Vulcanian. Stronger than strombolian but weaker than pulnian, ejects ashes, characterized by tall columns that reaches up to 20km
• Strombolian. The smallest type of explosive eruption, occurs when volcanic gasses pressure is excessively high.
• Strombolian is characterized by a fountain of lava, and features slow movement of lava
• Mt. Vesuvius erupted in 79 AD
• Mt. St. Helens erupted in 1980
• Mt. Pinatubo erupted in 1991.
• Phreatic. This type of eruption is caused when the water above the magma, and lava is heated.
• Phreatomagtic. A violent eruption, that features large columns and very fine ash, high speed and side way emission of pyroclastics
• Vulcanian characterized by tall eruptions columns that reaches upto 20km high with pyroclastic flow
• Primary factors which affects the magmas viscosity:

  The magmas temperature

  Chemical composition

  The amount of dissolved gasses it contains
• A crater is a funnel shaped at the top of the volcano
• Caldera is formed when a part of the wall of a volcano collapses