volcanic hazards

• Types of Volcanic Hazards


  • Lava flow
  • Dome growth
  • Pyroclastic flow
  • Pyroclastic surge
  • Pyroclastic lateral blast
  • Ashfall
  • Ballistic projectile
  • Volcanic gases
  • Lahar
  • Flooding
  • Debris avalanche
  • Landslide
  • Tsunami
  • Seiche
  • Subsidence
  • Fissuring
  • Secondary/hydrothermal explosion
  • Secondary pyroclastic flow
• Directly associated with eruption


  • Lava flow
  • Dome growth
  • Pyroclastic flow
  • Pyroclastic surge
  • Pyroclastic lateral blast
  • Ashfall
  • Ballistic projectile
  • Volcanic gases
• Indirectly associated with eruption


  • Lahar
  • Flooding
  • Debris avalanche
  • Landslide
  • Tsunami
  • Seiche
  • Subsidence
  • Fissuring
  • Secondary/hydrothermal explosion
  • Secondary pyroclastic flow
• Lahar


  Hot or cold mudflows that can destroy buildings, infrastructure, and crops
• Ashfall


  Fine particles that can collapse roofs, damage crops, and cause respiratory problems
• Pyroclastic Flows


  Extremely hot and fast-moving clouds of ash and gas that can incinerate everything in their path
• Ballistic Projectiles


  Large rocks launched from the volcano that can cause serious injury or death
• Volcanic Gases


  Toxic gases like sulfur dioxide that can irritate the lungs and cause breathing difficulties
• Lava Flows


  Molten rock that can destroy buildings, infrastructure, and block rivers
• Management of Volcanic Hazards

  • Monitoring
  • Hazard maps
  • Early warning systems
  • Evacuation plans
  • Education
• Monitoring


  Tracking volcanic activity to predict potential eruptions
• Hazard maps


  Identifying areas at risk from different volcanic hazards
• Early warning systems


  Alerting communities of imminent eruptions
• Evacuation plans


  Establishing procedures for evacuating people from danger zones
• Education


  Raising awareness of volcanic hazards and preparedness measures
• Signs of an Impending Eruption

  • Increased volcanic earthquakes
  • Changes in steaming activity
  • Crater glow
  • Ground deformation
  • Localized landslides
  • Drying vegetation
  • Increased hot spring activity
  • Changes in water chemistry
• Volcano Alert Levels


  • Permanent Danger Zone (PDZ)
  • Alert levels (may vary by agency)
• Permanent Danger Zone (PDZ)


  Area around a volcano at high risk from eruptions
• Alert levels


  Indicate the severity of volcanic activity and the potential for eruption
• Before a Volcanic Eruption

  • Evaluate the risk of your location
  • Develop an emergency plan for evacuation and communication
  • Prepare a disaster supply kit
• During a Volcanic Eruption

  • Follow instructions from authorities
  • Evacuate danger zones if instructed
  • Protect yourself from ashfall by wearing a mask and goggles
  • Stay indoors if possible
• After a Volcanic Eruption

  • Listen to updates on air quality and water safety
  • Be aware of the risk of lahars following heavy rainfall
  • Help with recovery efforts