Global Frequency of Earthquakes

How often do earthquakes occur?

Graph of global frequency
of various magnitude earthquakes

Earthquakes are always occurring somewhere in the world. Millions of small (too small to be felt) earthquakes happen every year, while major earthquakes happen, on average, about once per year. The graph above shows the relative frequency of various magnitude earthquakes (using the common Richter Magnitude scale on the left) and the equivalent amount of high explosive required to produce the same amount of energy release as the earthquake (using the kilograms of explosive scale on the right)

Several Canadian historical earthquakes and some natural and man-made explosions are shown for reference.

Our thanks to the IRIS consortium's Education and Outreach program for allowing us to modify their original figure.

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