Volcano Notes

Volcano Parts

  • Vent: Opening for magma to escape.
  • Ash Cloud: Cloud of volcanic ash.
  • Crater: Mouth of a volcano.
  • Conduit: Underground magma passage.
  • Magma Reservoir: Pool of liquid rock.

Volcano Locations

  • Ring of Fire: Pacific Ocean area with 90% of world's volcanoes and 75% of earthquakes.
  • Contains 452 volcanoes.

Origin of "Volcano"

  • From 'Vulcano' island in Italy.
  • Named after Roman god of fire, Vulcan.

Volcano Formation

  • Magma forms from Earth's mantle.
  • Pressure causes magma to rise and leak onto the surface.

Earth's Layers

  • Crust: Outer layer, 0-60km thick.
  • Mantle: 2897km thick, made of magma.
  • Outer Core: Liquid iron and nickel, creates Earth's magnetic field.
  • Inner Core: Solid iron and nickel, hottest part (up to 5500°C).

Composite Volcanoes

  • Formed from layers of volcanic rock and ash.
  • Prone to explosive eruptions.

Why Volcanoes Erupt

  • Earth's crust made of tectonic plates.
  • Plate movement causes friction and volcanic activity.

Number of Volcanoes

  • More than 1500 active volcanoes on Earth.
  • Over 80 volcanoes under the ocean.

Shield Volcanoes

  • Have gentle slopes due to runny lava.

Volcano Stages

  • Active: Recently erupted, may erupt again.
  • Dormant: Hasn't erupted recently, but may erupt in future.
  • Extinct: Unlikely to erupt again.

Volcano Examples

  • El Popo (Mexico): Dangerous volcano, erupted several times.
  • Mount St. Helens (USA): Active composite volcano, erupted in 1980.
  • Sunset Crater (USA): Cinder cone volcano.

Volcano Definitions

  • Magma: Hot fluid or semi-fluid rock below the Earth's crust.
  • Lava: Magma that has erupted onto the surface.
  • Friction: Resistance when surfaces rub together.

Volcanoes on Other Planets

  • Other planets and moons have volcanoes (most are extinct).
  • Mars: Olympus Mons is the largest volcano in the solar system.
  • Io (Jupiter's moon): Active volcanoes.
  • Triton (Neptune's moon): Active volcanoes that release ice.

Largest Active Volcano

  • Mauna Loa (Hawaii): Largest active volcano by volume and area.