earthquakes

• what is the focus/ hypocenter

  the point inside the crust from which the pressure is released
• what is the epicentre

  the point on the earths surface vertically above the focus
• seismic wave 


  how an earthquakes energy is released
• primary wave definition

  • travel through the earths body (body wave)
  • push through the crust mantle and core
  • fastest wave
  • travel through solids + liquids
• secondary wave

  • travel through the earths body (body wave)
  • shake through the crust and mantle only
  • travel through solids
  • cause more damage then primary waves
• love waves

  • travel along the earths surface (surface waves)
  • move side to side
  • slowest out of the 3 waves
  • largest
  • cause the most damage
• how are seismic waves measured

  measured using a seismometer, this detects and measures ground movement
• how are earthquakes measured

  • magnitude and intensity are used to measure earthquakes
  • magnitude is measured using the moment magnitude scale measuring the total energy
  • intensity is measured by the effect on people, structures and the environment. modified mecalli scale is used . takes observations and rates them.
• primary effects of an earthquake

  direct result of an earthquake

  ground shaking, crustal fracturing
• secondary effects 


  liquefaction: shaking causes surface rocks to loose strength and become more liquid then subsoil looses ability to support foundations.

  landslides, avalanches, tsunamis
• aftershocks 


  can cause additional damage and structures become weakened

  • occur for weeks, months, years
  • happen in the earthquakes general area
• predicting earthquakes 


  no method to predict when eq will strike although knowledge on plate tectonics shows areas of risk
• What is the definition of risk in the hazard risk equation?

  Probability of harmful consequences
• What factors contribute to vulnerability in the hazard risk equation?

  Physical, social, economic, environmental factors
• What does capacity to cope refer to in the context of disaster events?

  Use of resources during adverse conditions
• What is physical vulnerability?

  Living in hazard-prone areas
• What is economic vulnerability?

  Risk of losing jobs and assets
• What is social vulnerability?

  Inability to support disadvantaged individuals
• What is knowledge vulnerability?

  Lack of education or training
• What is environmental vulnerability?

  Increased hazard risk due to population pressure
• vulnerability

  the ability to anticipate, cope, resist and recover from natural disasters
• resilience

  the ability of a community to cope with a hazard.
• mega disaster

  2000+ deaths
• disaster

  500+ deaths
• governance 


  the process by which a country is run