How Often Do Earthquakes Occur?

Novice Spanish

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.

NOTE: Out of stock; self-printing only.

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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Related Software-Web-Apps

IRIS Earthquake Browser

The IRIS Earthquake Browser (IEB) is an interactive tool for exploring millions of seismic event epicenters (normally earthquakes) on a map of the world. Selections of up to 5000 events can also be viewed in 3D and freely rotated with the 3D Viewer companion tool. 

Software-Web-App Novice

Related Animations

Magnitude Explained: Moment Magnitude vs. Richter Scale

The "moment magnitude" scale has replaced the Richter scale for large earthquakes. Scientists have developed far-more sensitive seismometers that, with faster computers, have enabled them to record & interpret a broader spectrum of seismic signals than was possible in the 1930's, when the Richter magnitude was developed. Find out what scientists learn from seismograms.

Animation Novice