Geography - Tectonic Hazards

• What are tectonic plates?

  Parts of the earths crush floating on top of the mantle
• What are two types of tectonic plates?

  • Continental
  • Oceanic
• What is the difference between continental and oceanic crusts?

  • Continental plates are thicker
  • Oceanic plates are denser
• What causes tectonic plates to move?

  Convection currents in the mantle
• What is the place where tectonic plates meet called?

  Plate margin / boundary
• What are the 3 types of plate boundary?

  • Destructive
  • Constructive
  • Conservative
• In what direction are the plates at a destructive plate margin moving?

  Towards each other
• What happens at a destructive plate margin?

  • The denser oceanic plate subducts under the continental plate into the subduction zone. The heat of the mantle melts the oceanic crust and turns into into gas - rich magma. The magma rises through gaps in the crust to form composite volcanos.
  • If two continental crusts meet, the grounds folds up, forming fold mountains.
• What are the properties of a composite volcano?

  • Explosive
  • Viscous lava
  • Can form lahars
  • Release pyroclastic flows
• How can earthquakes form at destructive plate margins?

  Tensions builds up when one plate get stuck to another as it moves past
• What type of earthquakes occur at destructive plate margins?

  High Magnitude
• Name an example of a destructive plate margin

  Nazca plate and south American plate
• In what direction are plates moving at constructive plate margins?

  Away from each other
• What occurs at a constructive plate margin?

  As the plates move away from each other, magma rises through the gap formed. This magma cools to form ridges and shield volcanos.
• What are the properties of shield volcanos?

  • Not explosive
  • Runny lava
• What causes earthquakes at constructive plate margins?

  Tension builds along cracks in the plates as they move away from each other.
• What type of earthquakes occur at constructive plate margins?

  Low magnitude
• Give an example of constructive plate margin

  Eurasian plate and north American plate
• In what direction are plates moving at conservative plate margins?

  The same direction
• How do earthquakes occur at conservative plate margins?

  Tension builds up when the plates get stuck
• What types of earthquakes occur at conservative plate margins?

  High magnitude
• Give an example of a conservative plate margin

  Pacific plate and north American plate
• What are shock waves?

  Vibrations released by an earthquake
• What is the focus?

  The point in the earths crust in which the earthquake starts
• What is the epicenter?

  The point on the earths surface directly above the focus
• What is magnitude?

  A measure of the amount of energy released by an earthquake.
• What are the 4 ways in which the effects of tectonic hazards can be reduced?

  1. Monitoring
  2. Prediction
  3. Planning
  4. Protection
• How can you monitor for earthquakes and volcanic eruptions?

  • Earthquakes - Use seismometers and lasers to monitor the movement of plates
  • Volcanos - monitor signs that come before an eruption
• How can you predict earthquakes and volcanic eruptions?

  • Earthquakes - monitor movement of the earths crust
  • Volcanos - monitor volcanos closely
• How can you plan for earthquakes and volcanic eruptions?

  • Avoid high risk areas
  • Plan evacuation routes
  • Stockpile emergency supplies
• How can you be protected from earthquakes and volcanic eruptions?

  • Earthquakes - Aseismic buildings
  • Volcanos - Strengthen infrastructure
• Why do some people choose to live in areas with are high risk of tectonic hazards?

  • Friends/Family
  • Risk can be reduced by wealth
  • Tourism
  • Jobs
  • Minerals
  • Government support