Tectonic Hazards

• Earth Layers

  • Crust-solid
  • Mantle-solid
  • Outer Core-liquid
  • Inner Core- Liquid
• The earths crust is broken into large pieces called tectonic plates
• Continental Plates


  Thicker, older and lighter, they do not subduct
• Oceanic Plates


  Thinner, younger and denser so they can subduct under another plate
• Plate boundaries/ margins are the same thing. They describe the location Earth where 2 tectonic plates meet or sit next to each other
• Tectonic plates move according to the movement below in the mantle
• Convection currents are caused by heat from the core which causes hot rock to rise upwards and cool down as it moves away from the core.
• Some plates are pushed apart and some are being dragged together
• In convection, hot things that are less dense and have more energy rise
• Constructive Plate Margins

  • Plates move apart
  • Convection currents diverge, causing a gap to form between the plates
  • Magma rises up to fill the gap between the 2 plates
• Conservative Plate Boundaries

  • Plates slide past each other
  • Friction and pressure build up
  • They slip past each other, may resulting in the ground to shake (earthquake)
• Destructive Plate Boundaries

  • Oceanic plate slides under the continental plate (subduction)
  • Pressure builds up
  • May result in earthquakes
• Volcano


  An opening in the Earths crust that is formed when magma rises from inside the Earth and erupts through the Earths crust. Can be formed at destructive and constructive plate boundaries
• Hotspots happen at the Earths crust over hotter parts of the earths mantle
• Destructive Plate Margins

  • Highly explosive
  • Produce a lot of gas
  • Produce a lot of lava
• Volcanic Eruption

  • Lava
  • Gases- sulphur
  • Ash
  • Pyroclastic flows
• Pyroclastic flows


  Currents of hot ash, lava and gas that can move downhill at speeds up to 500km/h during an eruption
• Primary Effects: Lava, ash, gas, suffocation, crop and livestock deaths, human deaths and damaged buildings
• Secondary Effects: Increased soil fertility, lahars (mudslides), damaged infrastructure, flooding/tsunamis, lost forests and farmland, volcanic winter, economic damage
• Tsunami is caused by earthquakes or underwater landslide which causes waves on water surface