How Often Do Earthquakes Occur?

Earth is an active place and earthquakes are always happening somewhere. In fact, the National Earthquake Information Center locates about 12,000-14,000 earthquakes each year! This fact sheet illustrates information on the frequency of earthquakes of various magnitudes, along with details on the effects of earthquakes and the equivalent energy release. On average, Magnitude 2 and smaller earthquakes occur several hundred times a day world wide. Major earthquakes, greater than magnitude 7, happen more than once per month. "Great earthquakes", magnitude 8 and higher, occur about once a year.


Keypoints:

  • Earthquakes are always happening somewhere.
  • For each step up in magnitude the annual number of earthquakes decreases (roughly) by a factor of 10. 
  • For each step up in magnitude an earthquake releases 30 times more energy.
  • While the number of earthquakes that can be detected and located each year has been increasing, this doesn’t mean that the annual average number of earthquakes has increased.     

 

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