secondary impacts of earthquakes

• what is a secondary hazard


  the effects resulting from primary

  eg, sanitary destruction (primary) leads to water disease
• what is a risk


  the probability of a hazard event occuring and creating loss of life
• what is a hazard


  a percieved natural event which has the potential to threaten both life and property
• what is vunerability


  a high risk combined with an inability of individuals and communities to cope
• what is capacity to cope

  the ability of affected communities to cope with a given hazard
• what is the equation of risk

  hazard x vunerability

  -----------------------

  capacity to cope
• 4 secondary hazards

  soil liquefaction

  landslides + avalanches
• what is soil liquefaction


  violent destruction of the ground cases it to become liquid-like when strongly shaken

  
  

  the surface may seem dry however excess water such as ground water will sometimes come to the surface through cracks
• what does soil liquefaction cause

  the ground may crack which causes damage to surface structures and underground utilities

  - eg tube networks

  - pipes

  - buildings

  
  

  liquefaction in the Bay area due to the 1989 san francisco earthquake cost the US $100,000 million
• what are landslides/avalanches


  where slope failure occurs as the result of the ground shaking
• what do landslides/avalanches cause

  deaths

  environment destruction long + short term
• what are global hazards

  a widespread and potentially destructive event that poses significant threats to human societies, ecosystems, and economies on an international scale
• categories of global hazards

  hydrological and atmospheric

  geophysical

  natural-technological disasters

  context
• what is a hydrological and atmospheric hazard

  a hazard formed by hydrological (floods) and atmospheric (storms and droughts) processess
• what is a geophysical hazard

  a hazard formed by tectonic/geological processes eg earthquakes, volcanoes and tsuamis
• what is a natural-technological disaster


  where natural hazards trigger technological disasters eg flooding causes a dam to burst
• what is a context hazard

  Widespread (global) threat due to environmental factors such as climate change
• what is a multi hazard zone

  an area which is prone to a range of hazards, some of these may be interrelated, such as earthquake triggering landslide