L5

• Volcano


  An opening in the earth's crust through which lava, volcanic ash, and gases escape. Volcanic eruptions are 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
• Active volcanoes


  • Have a recent history of eruptions; they are likely to erupt again
• Dormant volcanoes


  • Have not erupted for a very long time but may erupt at a future time
• Dormant volcanoes

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


  • Are not expected to erupt in the future
• 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. The fragmented rock may be accompanied by ash and gases
• Volcanic hazards

  Phenomena arising from volcanic activity that pose potential harm/threat to people or property in a given area within a given period of time
• Lava flows


  • A stream of molten rocks that pour or ooze from an erupting vent
  • Eruptive during explosive or non explosive activity
• Ash fall or tephra fall


  • Also known as "volcanic ash"
  • Often loosely used to refer to all explosive eruption products including dissolved gases in magma
  • It is 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
• Pyroclastic flows and surges can destroy anything on its path, burn sites, forest, farmlands, destroy crops and buildings
• Lahars


  • A mudflow made up of volcanic debris
  • Detected by small slope collapses that gather water
  • Through rapid melting of snow and ice
  • From heavy rainfall on loose volcanic debris
  • Volcano erupts through crater lake
• Volcanic gases


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

  
• Volcanic gases and their effects

  • CO2 - Carbon dioxide - trapped in low-lying areas can be lethal to people and animals
  • SO2 - Sulfur dioxide - Is irritating to eyes, skin and respiratory system
  • H2S - Hydrogen sulfide - is very toxic in high concentrations (Exposure to 500 ppm can cause a human to fall unconscious in 5 minutes and die in an hour or less)
  • HF, HCl, HBr - Hydrogen halides - are toxic acids (can poison drinking water supplies, agricultural crops, and grazing land)
• Ballistic projectiles


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


  1. Before:

  2. Evacuate immediately if you live or are staying within the radius of affected areas

  3. Stay tuned to national news and your local community's channels

  4. Charge your electronics

  5. Know disaster hotlines and other emergency hotlines

  6. Prepare a go-bag in case of evacuation

  7. During:

  8. Use an N95 dust mask to protect yourself

  9. Protect your skin and eyes

  10. Secure your pets inside your home

  11. If you are outside, seek cover immediately

  12. If you are inside, stay tuned to the news

  13. If you are driving, pull over and stop

  14. Cover food and water containers

  15. After:

  16. Do not leave your home or indoor shelters until notified

  17. Wear protection when clearing out ash

  18. Clean your gutters and roof

  19. Wait for further announcements from LGUs or national news