earthquakes

• earthquake features


  focus - where shaking originates from within the Earth

  epicentre - above the shaking focus

  seismic wave - shock waves released by an earthquake

  plate movement - movement of plant

  A) focus

  B) epicentre

  C) seismic waves

  D) plate movement

  
• primary effects of an earthquake

  • death
  • damage to property
  • injuries
  • water pipes burst
  • damage to infrastructure - eg roads
• secondary effects of an earthquakes

  • death
  • electrical cable damage
  • fires due to downed power lines
  • emergency service unable to reach people
  • slow down economy as funds are spent on recovery
  • injuries
  • water pipes burst
  • scarcity of fresh water
  • disease from lack of sanitation and fresh water
• how are earthquakes measure


  Richter scale

  moment magnitude scale

  both show how the magnitude and energy equivalent of the event

  they are logarithmic which means that each magnitude power increases in tenfold

  Chile - 1960 = 9.5M - worse recorded earthquake
• factors effecting severity;

  • depth of focus - proximity to the surface - deeper down - less severe, shallow = more severe - dangerous
  • location of epicentre - cities = more severe (more risks - people, buildings)
  • time of day - night - asleep, busy times of day - more people are out
  • geology - hard rock - absorbs energy, withstands shaking - less severe -- soft rock = least resistance
• factors effecting severity

  • population density - cities (more populated) - higher risk of injury
  • level of development - HIC ; afford to repair, prepare - LIC ; can't afford to prepare and repair, Haiti
  • quality of buildings - better quality buildings can withstand the shaking