Seismic Hazards

  • Created by: hollyjxne
  • Created on: 13-05-18 18:16
View mindmap
  • Seismic Hazards
    • Earthquakes are the primary hazard of seismic activity
      • Tension created at plate boundaries, when plates jerk past each other vibrations are sent out
        • shockwaves (vibrations) are spread out from the focus.
          • The epicenter is the point on earths surface where earthquake is first felt.
        • ground shakes and sometimes ruptures
      • Measuring the scale of an earthquake
        • Mercalli Scale
          • Measures impacts using observations, scale of 1-12
        • Richter Scale
          • measures magnitude and is logarithmic
        • Moment Magnitude Scale
          • Based on total amount of energy released and is logarithmic
      • Tsunamis
        • Large waves caused  by the displacement of a large volume of water
          • Triggered  by underwater earthquakes, whereby the seabed moves
        • More poreful when closer to the coast
      • Soil liquefication
        • Soil is over saturated with water and so the vibrations cause it to act like water
          • Soil is made weak and is easier to deform so more likely to subside
    • Tsunamis
      • Large waves caused  by the displacement of a large volume of water
        • Triggered  by underwater earthquakes, whereby the seabed moves
      • More poreful when closer to the coast
    • Landslides and avalanches
      • Earthquakes are the primary hazard of seismic activity
        • Tension created at plate boundaries, when plates jerk past each other vibrations are sent out
          • shockwaves (vibrations) are spread out from the focus.
            • The epicenter is the point on earths surface where earthquake is first felt.
          • ground shakes and sometimes ruptures
        • Measuring the scale of an earthquake
          • Mercalli Scale
            • Measures impacts using observations, scale of 1-12
          • Richter Scale
            • measures magnitude and is logarithmic
          • Moment Magnitude Scale
            • Based on total amount of energy released and is logarithmic
        • Soil liquefication
          • Soil is over saturated with water and so the vibrations cause it to act like water
            • Soil is made weak and is easier to deform so more likely to subside
      • Shaking causes rocks and soils to dislodge and cause landslides
    • Location of seismic hazards
      • Margin type
        • Biggest /highest magnitude earthquakes  @ destructive margins
      • Depth of focus
        • Deep focus = higher magnitude but less damage as shockwaves have further to travel

Comments

No comments have yet been made

Similar Geography resources:

See all Geography resources »See all Natural hazards resources »