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Earthquake Effects

Earthquake Effects

Primary Effects

  • Short periods of intense ground motion
    • Can damage human structures
    • “Earthquakes don’t kill people, buildings kill people”
  • A few factors determine the amount and intensity of damage done
    • Key factor of intensity of damage is the earthquake’s magnitude
    • Length is also important (larger earthquakes tend to be longer)
    • How buildings are structured and constructed
    • Surface materials on which structures are built
    • Structures on loose/sedimentary materials usually experience more intense shaking
    • Structures on solid rock are generally more stable
    • Some structures can be engineered specifically to mitigate earthquake damage

Secondary Effects

  • Other processes related to the shaking
  • Mountainous areas → landslides (loose rocks/soil break free)
  • Wet, low-lying areas → liquefaction (wet soils liquify)
    • Especially common in areas of sandy soils
  • Ground cracking
  • Fire
    • Shaking may break gas lines, which catch fire
    • Eg. 1906 San Francisco earthquake → wooden buildings survived quake but not fire
  • Tsunamis
    • Fault movements displace water above the fault
    • Waves radiate from epicenter
    • Not overly noticeable in middle of ocean, but can wreck coastal areas
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