Volcanic Eruptions

• Volcano


  An opening in the Earth's surface that allows the energy from the interior of the Earth to escape to the surface

  
• Magma


  The molten rock materials beneath the Earth's surface
• Lava


  Magma that have already reached the surface of a volcano

  
• Lahar


  • A mixture of water, pyroclastic materials and rock fragments flowing down a volcano or river valley
  • Highly destructive to anything in its path
  • May partially or completely bury buildings and other structures
• Ash Fall


  • The fragments measure less than 2mm in diameter.
  • Composed of bits and pieces of pulverized rock, minerals and volcanic glass
  • May cause change in local climate
  • May cause the collapse of buildings
  • May corrode building materials or destroy agricultural lands
  • May clog air filters in vehicles
  • May pose health problems (respiratory diseases)
• Pyroclastic Flow


  • A fast-moving fluidized mass of rock fragments and gases
  • Maintains a very high temperature, burning everything in its path
• Ballistic Projectile


  • A rock fragment that is ejected from a volcano during its explosive eruption
  • Two types are bomb and block.
  • Bombs are partially molten or molten when ejected
  • Blocks are solid when ejected
  • Pose a serious hazard to humans, animals, plants and properties
  • Can travel as far as 5 kilometers or even further
• Volcanic Gas


  • Consists of Sulfur dioxide and hydrogen sulfide which are poisonous and hazardous to organisms
  • Causes acid rain which corrodes structures and plants
  • May cause respiratory problems and other health risks
• Lava Flow


  • A molten rock material that pours down from the slopes of the volcano
  • Denser and moves more slowly than pyroclastic flow
  • May destroy vegetation, houses, infrastructures and can also cause forest fire

  
• Signs of Impending Volcanic Eruptions


  • Occurrence of tremors or increase frequency of low intensity earthquakes
  • Deformation in the ground manifested by change in ground elevation
  • Increase amount of volcanic gases and temperature
  • Glow of volcanic crater due to presence of magma
  • Thermal change within the surrounding of the volcano
  • Change in color of nearby vegetation and lakes
  • Landslide or rock fall not due to heavy rains
  • Drying up of springs and freshwater sources around the volcano

  
• Alert Levels


  • 0 - Quiet or No Alert
  • 1 - Low Level of Volcanic Unrest
  • 2 - Moderate Level of Volcanic Unrest
  • 3 - High Level of Volcanic Unrest
  • 4 - Hazardous Eruption Imminent
  • 5 - Hazardous Eruption in Progress

  
• Stand-Down Procedures


  • From Level 5 to Level 4: Wait at least 24 hours after hazardous activity stops
  • From Level 4 to Level 3 or 2: Wait at least 2 weeks after activity drops below Level 4
  • From Level 3 to Level 2: Wait 2 weeks after activity drops below Level 3
• Precautionary and Safety Measures Before Volcanic Eruptions


  • Stay updated with the local news
  • Prepare a family emergency preparedness plan
  • Prepare an emergency supply kit
  • Pack all important and essential items in a light and waterproof containers
  • Secure livestock in enclosed shelters
  • Listen to public safety announcements of local authorities
• Precautionary and Safety Measures During Volcanic Eruptions


  • Follow evacuation orders issued by authorities and stay in the designated evacuation centers
  • If told to stay indoors, Keep your windows and doors closed and place damp clothes to all openings to prevent the entry of ashes
  • Wear long sleeves and long pants
  • Wear goggles to protect your eyes
  • Use face mask or damp cloth over your face to prevent inhalation of ashes and other volcanic particles
  • Listen to your radio for the latest emergency information
• Precautionary and Safety Measures After Volcanic Eruptions


  • Wait for the announcement from authorities before going back to your houses
  • Inspect your house for any damage and refer to authorities if it you are not sure of the structural condition of your house
  • Family members with respiratory problems should be kept away from ashes and other volcanic particles
  • Wear a dust mask, gloves and goggles when cleaning the debris and ashfalls in your area
  • Check the electrical wiring, appliances and gas tank before using them
  • Stay informed and listen to emergency updates and news
• BE ALERT AND BE GUIDED BY THE INFORMATION COMING FROM NDRRMC AND MDRRMC/CDRRMC
• The 90-kilometer West Valley Fault runs from the Angat reservoir in Bulacan through Quezon City, Marikina, Pasig, Makati, Taguig, Muntinlupa, Rodriguez Rizal, Cavite and ends in Calamba, Laguna. The West Valley Fault can generate a large earthquake with M 7.2 which threatens to lives, buildings and infrastructures, and livelihood.
• The Philippine Institute of Volcanology and Seismology (PHIVOLCS) is responsible for monitoring and assessing the status of active volcanoes in the country. It also provides advisories on volcanic eruption and seismic activities.
• The National Disaster Risk Reduction Management Council (NDRRMC), chaired by the President, coordinates disaster risk reduction efforts among national government agencies and local governments units. It issues warnings and alerts during disasters and emergencies.
• Lahars may be generated by intense rainfall over the volcano area and may affect riverside communities far down the PDZ.
• Sulfur Dioxide is a major gas component of magma.
• Volcanic Hazards are volcano- related phenomena that pose potential threat or negative impact to life, property and environment.
• BLOCK – if the projectile or rock is solid when ejected.
• •BOMB – it is launched partially molten or in molten state.
• ASHFALL - fine particles of ash from an explosive eruption can travel long distances and cause respiratory problems.
• •ASHFLOW - it is composed of ash, pumice fragments, and other lightweight materials.
• PYROCLASTIC FLOW - a fast moving mixture of hot gases, ash, pumice, and rocks that flows rapidly down the slopes of a volcano at speeds up to 700 km/hr.
• •LAHAR – it is a mudflow consisting of water, rocks, boulders, tree trunks, logs, and vegetation debris.
• •PYROCLASTIC FLOWS – they are hot clouds of gases and solids moving at high speeds from an erupting vent.