science

• Magma

  Extremely hot liquid and semi-liquid rock under Earth’s surface
• When there is enough magma and enough pressure on it

  A volcanic eruption occurs
• Throat


  Central tube where the magma rises up and emerges out the top of the mountain
• Types of eruption

  • Effusive eruption
  • Explosive eruption
• Water content and silica content affect bubble formation
• Magma composition affects how a volcano erupts
• Volcano


  Any place where gases and melted rock (magma) come out of the ground
• Effusive eruption


  • Also known as Quiet or nonexplosive eruption
  • Most common type of eruption
  • Produces calm lava flow
  • Releases huge amounts of lava but less ash and dust
• Types of volcanoes

  • Shield volcano
  • Cinder cone volcano
  • Composite volcano (stratovolcanoes)
• Explosive eruption


  • Less common but more destructive
  • Produces clouds of hot ash, gas, and rock fragments
  • Does not produce lava flows
• Crater


  The opening at the top of a volcano
• Pyroclastic materials

  • Hardened magma that is blasted into the air
  • Produced by explosive eruptions
• Mantle


  The layer under the earth’s surface where the lava comes up
• Bubble formation in magma

  1. More water results in more bubble formation

  2. More silica results in less bubble formation
• Magma can push through holes in the crust


  Causing a volcanic eruption
• Vents


  Openings in the earth’s crust where magma escapes
• Lava


  • Magma that flows on the Earth’s surface
  • Produced by effusive (nonexplosive) eruptions
• Volcanic eruption styles

  • Icelandic
  • Hawaiian
  • Strombolian
  • Vulcanian
  • Pelean
  • Plinian
• Magma consists much of the planet's mantle
• Magma chamber


  Underneath a volcano is a pool of molten rock
• Caldera


  A large depression that forms when a magma chamber collapses
• Earth's layered structure

  • Inner core
  • Outer core
  • Mantle
  • Crust
• Pyroclastic materials

  • Ash
  • Gas
  • Rock fragments
• Viscosity


  The resistance to flow