TECTONIC HAZARDS

• how to monitor + predict and earthquake:

  • seismometer - identifies tremors or foreshocks using seismic waves
  • patterns of earthquakes
  • random detectors - measures gasses in groundwater and soil
  • animals acting strangely
• how to plan in case of an earthquake:

  • fasten furniture to the ground and walls
  • turn off gas, electricity and water
  • practice earthquake drill (1st September in Japan)
  • have emergency aid supplies
• how to protect for an earthquake:

  • secure infrastructure - roads, building and bridges (usually done in HICs as it's expensive)
  • shock absorbers - rubber under buildings that absorbs tremors
  • sheer walls - concrete walls with steel in them to reduce movement
  • cross-bracing - steel bracing over walls to reinforce them
  • rolling weights - weights that go the opposite way of the building
• how to monitor + predict a volcano:

  • thermal heat sensors - measures the change in temperature
  • tilt meter - measures the ground changing
  • water levels and temperature
• how to plan in case of a volcano:

  • have evacuation plans
  • prepare shelters, food supplies and strategies
  • practice in advance - cover eyes and mouth from the fumes
  • create a hazard map - routes of lahars, pyroclastic and lava flow
• how to protect for a volcano:

  • evacuation
  • difficult as buildings rarely withstand lahars, ash fall, pyroclastic and lava flow
• monitoring


  where specialist equipment is used to warn when a tectonic hazard will occur e.g. seismometer
• prediction


  data from monitoring that gives an indication of a hazard occurring
• protection


  buildings that withstand shaking e.g. aseismic buildings
• planning


  when authorities or individuals can create routes for evacuation
• conservative plate margin

  • plates move parallel to each other at different speeds or directions, strain energy builds up until the plates release and slide past each other
  • no volcanoes
  • large earthquakes

  A) conservative

  
• constructive plate margin

  • two oceanic plates move apart from each other that creates a gap between them where magma then moves up to fill it
  • yes volcanoes
  • small earthquakes

  A) constructive

  
• destructive plate margin

  • one oceanic, one continental plate move towards each other and get locked together, the oceanic subducts and once they're released strain energy is also released
  • yes volcanoes
  • large earthquakes

  A) destructive

  
• ridge push


  hot magma rises up, heating the plate and lifts is
• slab pull


  cooling plate becomes denser and subducts, this pulls the plate into the mantle
• oceanic crust


  thin (5 - 10 km), dense, formed of basaltic crust, constantly recycled
• continental crust


  thick (20 - 200 km), less dense, formed of mainly granite rock