VOLCANOES

• acid rain

  formed when sulphurous gases mix with atmospheric water vapour
• lahar - mud flow

  mixture of water and ash that flows down the side of a volcano
• land slides

  a collapse of a mass of earth or rock from a mountain or cliff
• lava flow

  molten rock flowing on the earth's surface
• pyroclastic flow

  mixture of hot rock, lava, ash and gases that move fast along the ground
• ash and tephra

  rock fragments ejected during volcanic eruptions
• tsunami

  a large wave triggered by a volcanic landslide
• volcanic gases

  can include carbon dioxide, sulphur dioxide and chlorine
• Volcanoes at a destructive plate margin:

  1. Oceanic plate subducted or pulled down into the mantle beneath the lighter continental plate
  2. Creates a deep ocean trench at the surface
  3. Part of the mantle melts as the oceanic plate sinks deeper
  4. Hot magma rises up through the overlying mantle and lithosphere
  5. Magma erupts out at the surface producing a linear belt of volcanoes
• volcanoes at a constructive plate margin:

  1. oceanic plates move apart from ridge push+ slab pull
  2. Magma rises up a cools into solid rock, in some parts magma erupts - less viscous lava, it spreads out before cooling.
  3. Shield volcanoes are formed - wide base + gentle slopes
• immediate responses:

  • provide supplies of gas and electricity
  • treat injured people
  • rescue cut-off people
  • evacuate
  • provide food
• long-term responses:

  • improve, repair and update monitoring and evacuation plans
  • boost economy by attracting tourists
  • repair, rebuild and resettle people
  • repair and reconnect infrastructure