# Daily Archives: April 7, 2012

## 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

$N = 10^{a-bM}$,

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