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Flashcards in Earthquakes Deck (2)
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What are earthquakes and how are they caused?

  • Earthquakes are a seismic event resulting from tectonic movement
  • They are caused by tension that builds up at all types of plate margins
  • When plates violently jerk past each other, it causes an earthquake due to vibrations
  • The shock waves spread out around the focus, and the earthquake gets weaker the further way it is from the focus

How is an earthquake measured?

  • Measured on the Richter scale
  • It has no upper limit and is logarithmic, meaning for each stage it increases, its power is 10x the previous stage. E.g. An earthquake with a magnitude of 5 is 10 times greater than one with a magnitude of 4
  • The Mercalli scale measures the impacts of an earthquake using observations of the event
  • Scale is between 1-12
  • 1 being only detected with instruments and 12 being total destruction