LESSON 5: VOLCANO

• Volcano


  An opening in the earth's crust through which lava, volcanic ash, and gases escape
• Volcanic eruption


  Partly driven by pressure from dissolved gas, much as escaping gases force the cork out of a bottle of champagne
• Types of volcanoes


  • Active
  • Dormant
  • Extinct
• Dormant volcanoes


  • Mt. Makiling (Laguna)
  • Mt. Iraya (Batanes)
  • Mt. Alu (Sulu)
  • Mt. Abuyog (Leyte)
  • Iriga (Camarines Sur)
• Extinct volcanoes


  • Mount Butay
  • Mount Guinsiliban on Camiguin
• Effusive eruption


  Lava flows like a thick, sticky liquid
• Explosive eruption


  Fragmented lava explodes out of a vent, accompanied by ash and gases
• Volcanic hazards


  • Lava flows
  • Ash fall or tephra fall
  • Pyroclastic flows and surges
  • Lahars
  • Volcanic gases
  • Ballistic projectiles
• Lava flow


  A stream of molten rocks that pour or ooze from an erupting vent
• Ash fall or tephra fall


  Also known as "volcanic ash", a widespread distribution by wind
• Pyroclastic flows and surges


  Turbulent mass of ejected fragmented volcanic materials mix with hot gases that flow downslope at very high speeds
• Lahars


  A mudflow made up of volcanic debris, detected by small slope collapses, gathering water through rapid melting of snow and ice, from heavy rainfall on loose volcanic debris, and volcano erupts through crater lake
• Volcanic gases


  As magma rises, gases are released from the liquid portion of the magma (melt) and continue to travel upward, and large eruptions can release enormous amounts of gas in short time
• Ballistic projectiles


  Volcanic materials directly ejected from the volcano's vent with force and trajectory, and rocks that an erupting volcano may hurl into the air
• Precautionary measures before a volcanic eruption


  1. Evacuate immediately if within affected areas

  2. Stay tuned to national news and local community channels

  3. Charge electronics

  4. Know disaster hotlines

  5. Prepare a go-bag
• Precautionary measures during a volcanic eruption


  1. Use N95 mask or damp handkerchief

  2. Protect skin and eyes

  3. Secure pets

  4. Seek cover if outside

  5. Stay inside and close doors/windows

  6. Pull over if driving

  7. Cover food and water

  8. Wash utensils
• Precautionary measures after a volcanic eruption


  1. Do not leave until notified it's safe

  2. Wear protection when clearing ash

  3. Clean gutters and roof

  4. Wait for further announcements