Geography tectonic hazards

    Cards (29)

    • Inner core
      About 1400km in diameter, a solid and dense layer composed of iron and nickel with temperatures of about 5500°C
    • Outer core
      About 2100km thick, a semi-molten metal layer with temperatures between about 5000-5500°C
    • Mantle
      About 2900km thick, a semi-molten layer which is less dense than the outer core
    • Crust
      The thickness varies, and is made up of two types of crust
    • Types of crust
      • Oceanic crust
      • Continental crust
    • Oceanic crust
      • Thinner (5-10km) but heavier and denser
    • Continental crust

      • Thicker (25-90km) but is older and lighter
    • Oceanic crust is continually being created and destroyed as a result of plate movement where it is denser and so subducts under the continental crust
    • Continental crust is much older than oceanic crust, as it isn't destroyed
    • Tectonic plates
      The crust is broken into a number of tectonic plates
    • Tectonic theory once stated the movement of the plates was the result of convection currents in the mantle
    • Slab pull theory
      Current theory which suggests that the movement is the result of the weight of the denser oceanic plates subducting and dragging the rest of the plate along
    • Plate boundary or margin
      Where two plates meet
    • Plate boundaries
      • Constructive
      • Destructive
      • Conservative (transform)
    • Volcanic eruptions and earthquakes most commonly occur at or near plate boundaries
    • Primary effects of earthquakes
      • Buildings and homes destroyed/damaged
      • People Injured/killed
      • Transport routes destroyed/damaged
      • Water/gas/electricity supplies cut
    • Secondary effects of earthquakes
      • Economy slows as businesses take time to re-establish and money is spent on rebuilding
      • Aid struggles to reach those in need due to damaged/destroyed transport routes
      • Fires start due to broken gas and electricity supplies
      • Lack of clean water leads to disease
      • Damaged/destroyed homes lead to homelessness
      • Food prices increase
    • Primary effects of volcanic eruptions
      • Buildings, homes and farmland destroyed/damaged
      • People injured/killed
      • Transport routes destroyed/damaged
      • Aircraft grounded due to ash in the atmosphere
      • Contaminated water supply
      • Ash fall buries houses/crops
    • Secondary effects of volcanic eruptions
      • Economy slows as businesses take time to re-establish and money is spent on rebuilding
      • Aid struggles to reach those in need due to damaged/destroyed transport routes
      • Lack of clean water leads to disease
      • Damaged/destroyed homes lead to homelessness
      • Flooding caused by ice/snow melting on the volcano slopes may also cause lahars
      • Food prices increase
    • Immediate responses to tectonic hazards
      • Rescue teams search for survivors
      • Medical assistance for those injured
      • Shelter provided for homeless
      • Food and water provided
      • Recovery and burial of bodies
      • Warnings issued if possible
      • Evacuation
      • Clearing ash and debris
    • Long-term responses to tectonic hazards
      • Rebuild homes and other buildings
      • Improve building regulations
      • Improve drills, evacuation plans and warning systems
      • Repair water, gas and electricity supplies
      • Money given to farms for seed and new livestock
      • Data from eruptions used to improve future predictions
      • Government planning improved
      • Transport routes rebuilt
    • Reasons why people live in tectonically active areas
      • Fertile soils
      • Tourism
      • Minerals and precious stones
      • Geothermal energy
      • Creating new land area
      • Don't want to leave family and friends
      • Have always lived there and don't want to leave
      • As technologies and prediction improve people are also more confident that they are prepared for the hazard
    • Monitoring equipment for volcanoes
      • Seismometers
      • Lasers and tiltmeters
      • Remote sensing
      • Gas sensors
    • Monitoring equipment for earthquakes
      • Seismometers
      • Gas sensors
      • Ground water levels
    • Accurate timings for volcanic eruptions are not possible
    • It is impossible to predict the date, time or location of earthquakes
    • Protection measures for volcanoes
      • Evacuation and exclusion zones
      • Strengthening of roofs to support weight of falling ash
    • Protection measures for earthquakes
      • Earthquake drills
      • Earthquake resistant building design
      • Sea walls to protect against tsunami
    • Planning measures for volcanoes and earthquakes
      • Hazard mapping and risk assessment
      • Evacuation plans
      • Education about what actions to take, including drills
      • Stockpile of emergency supplies
      • Training of emergency services
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