Moment Magnitude - Reflexions

Moment Magnitude

The magnitude of energy measured during a seism. The more energy the seism has freed, the higher the magnitude. But it consists of a logarithmic scale: an increase of a magnitude of 1 corresponds to a multiplication of energy by 30 and by 10 for the amplitude of ground swing. The best known measuring scale is that imagined by Richter in 1935, which does nevertheless not measure the intensity of energy but rather the amplitude on a seismograph. It is hardly used today. What the media wrongly call the Richter scale in fact corresponds to the scale of moment magnitude conceived by Hiroo Kanamori in 1977. This scale is linked to the seismic moment, a measure of the seism’s energy.