Gutenberg-Richter

In a comment on the last post, it was mentioned that the frequency of earthquakes of any given magnitude or greater will be given by the Gutenberg-Richter law. It states that the expected number of earthquakes in a given region over a given span of time, of a given earthquake magnitude or greater, will be

,

where is the quake magnitude, and are constants, and is the expected number. For active regions, the constant usually has a value near 1.

Open Thread

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Deja Vu

A new study by scientists from the U.S. Geological Survey, not yet published but scheduled to be presented at the upcoming annual meeting of the Seismological Society of America, reports a dramatic increase in earthquakes of magnitude 3.0 or greater over a large area of the U.S. More interestingly, the report states that the increase is “almost certainly man-made,” and attributes it to oil and gas production.