volcanic eruptions

• magma


  Volcanoes erupt when molten rock called ___________ rises to the surface.
• quiet violent explosive


  Volcanic eruptions may be?
• effusive explosive


  2 types of eruptive styles
• effusive eruptions


  they produce lava flows exclusively.
• effusive eruptions


  generally applies to low-viscosity lavas, which can flow in sheets or shoot up as fountains.
• explosive eruptions


  produce pyroclastic debris due to the sudden release of built-up pressure.
• gas expansion


  What is the main source of the pressure when a volcano erupts explosively caused by decompression and flash boiling of water?
• magmatic phreatomagmatic phreatic


  types of eruptions based on their eruptive styles and height of eruption columns
• magmatic eruptions


  These are driven by thermal expansion of the dissolved gases in lava.
• plinian pelean vulcanian icelandic strombolian hawaiian surtseyan


  types of magmatic eruptions
• plinian eruptions


  result from the extreme build up of gases in the magma chamber and conduit with eruption column higher than 10 km
• higher than 10 km


  what is the eruption column of plinian eruptions?
• pelean eruptions


  These eruptions are characterized by nuée ardente or "glowing avalanches."
• vulcanian eruptions


  result from more viscous lava which builds up until it explodes, ejecting large volumes of pyroclastics and an eruption column 5-10 km
• 5-10 km


  what is the eruption column of vulcanian eruptions?
• icelandic eruptions


  sustained fissure eruptions, producing curtains of basaltic lava and produce large igneous provinces (LIPs)
• strombolian eruptions


  result of the bursting of clumps of gas bubbles with incandescent lava flows, with eruption column that is less than 5km
• less than 5 km


  what is the eruption column of strombolian eruptions?
• hawaiian eruptions


  produce low-viscosity basaltic lava flows and fountains and evolve from Icelandic eruptions
• surtseyan eruptions


  occurs in shallow bodies of water and are characterized by strong explosions as a result of magma coming in contact with water.
• phreatomagmatic eruptions


  driven by the violent thermal contraction of magma when it interacts with water, resulting in an explosion.
• phreatomagmatic eruptions


  It is the equivalent of a "wet" Strombolian eruption.
• surtseyan eruption


  best example of a phreatomagmatic eruption, caused by shallow-water lava interaction at sea or with an aquifer is called what?
• phreatic eruptions


  purely steam-driven, caused by the expansion of water into steam when heated by a nearby magma chamber or volcanic source.
• phreatic eruptions


  water flash boils and explodes, fracturing surrounding rock and even tearing off debris.
• volcanic explosivity index


  measure of the explosiveness of a volcano