Moment magnitude scale released, and an increase of two steps corresponds to a 10 (1,000) times increase in energy. Thus, an earthquake of "M" of 7.0 releases about 32 times as much energy as one of 6.0 and nearly 1,000 times one of 5.0. The moment magnitude is based on the seismic moment of the earthquake, which is equal to the shear modulus of the rock near the fault multiplied by the average amount of slip on the fault and the size of the area that slipped. Since January 2002, the MMS has been the scale used by the United States Geological Survey
Seismic magnitude scales well" with the seismic moment magnitude in the range of 4.5 to 7.5, but underestimate larger magnitudes. Body-waves consist of P-waves that are the first to arrive (see seismogram), or S-waves, or reflections of either. Body-waves travel through rock directly. The original "body-wave magnitude" – mB or m (uppercase "B") – was developed by and to overcome the distance and magnitude limitations of the scale inherent in the use of surface waves. is based on the P- and S-waves, measured over a longer period, and does not saturate until around M 8. However, it is not sensitive to events smaller