Tectonic hazards

• Plate boundaries


  Also called plate margins, the parts of the world where one tectonic plate is next to another
• Constructive (divergent) plate boundaries


  • Magma rising up in the mantle below, cooling off and spreading out to create new crust
  • Mostly appear at the bottom of the sea, with some evidence on land like in Iceland
• Magma and gases like carbon dioxide along constructive boundaries


  Can melt through the crust and get released out, causing volcanic eruptions
• Earthquakes happen at constructive boundaries but aren't usually that powerful
• Destructive (convergent) plate boundaries

  • Tectonic plates being carried towards each other
  • Oceanic plate forced underneath continental plate in subduction
  • Water and dead plankton dragged down, turned into water vapour and carbon dioxide which bubble up and melt continental crust
  • Pressure builds up and eventually erupts violently
  • Extremely powerful earthquakes can happen as plates get stuck and then suddenly unstuck
• Collision (convergent) plate boundaries

  • Both plates are continental, so they crash head-on and crumple upwards creating mountains like the Himalayas
  • Plates grind, crack and buckle upwards over millions of years, getting stuck and then suddenly unstuck, causing earthquakes
• No volcanoes at collision boundaries, as there is no magma rising up from underneath
• Conservative (transform) plate boundaries

  • Tectonic plates sliding past each other, either in opposite directions or at different speeds
  • Plate edges get stuck and then jump back into moving, releasing energy and causing earthquakes
  • No magma rising up, so no volcanoes