Hazards

• Blast/Explosion


  Close to Volcano - damage to buildings, trees blasted away
• Lava Flows


  Slow moving - rarely kills but destroys properies and agricultural land

  low viscous - ‘fissure’ eruptions are most dangerous

  Viscous - ‘sticky’ lava types move more slowly and rarely spread from source
• Pyroclastic Material


  Magma can be explosively erupted as particles

  Area around volcano is often uneven

  vary in size due to: Clast size, velocity and wind direction, gradient of size of volcano, magma viscosity
• Ash (<2mm): Forms rock tuff once lithified

  Lapilli (2mm - 64mm): Forms Lapilli Tuff

  Bombs (>64mm): Agglomerate once lithified (close to crater of volcano)
• Ash Fall


  Affects wide area.

  Damage to Property - weight can cause roof collapse

  Toxic chemicals can poison the soil - food shortages
• Pyroclastic Flow


  Contains a high density mix of hot lava blocks, pumice, ash & volcanic gas.

  Move at high speeds

  High Temps. (200 - 700) can ignite fires

  Responsible for many deaths as unpredictable
• Volcanic Gas


  Water vapour, CO2 & SO2.

  Rainfall near volcanoes are acidic. Fumatoles on or near volcanoes can emit these gases
• CO2 is not poisonous in ‘normal’ amounts in the air; However, because it is heavier than air, it collects in depressions and can suffocate anything that wondering into pockets of it
• Lahar


  Mudflow made of volcanic debris. Water based, pyroclastic flows are gas based. Can happen Weeks/Months after eruption, move Quickly and are destructive but only travel in valleys

  Formed Via:

  Rapid melting of snow & Ice

  Heavy rainfall on loose volcanic debris

  Volcano erupts through a crater lake

  When a Crater lake drains due to overflow
• Landslides


  Gravity-driven slides of masses of rock and loose volcanic material.

  During an eruption, heavy rainfall or earthquake - more likely on steep slopes
• Tsunamis


  Created by explosive eruptions on volcanic islands