1999 Jiji earthquake The tremor measured 7.6 on the Moment magnitude scale, 7.3 on the Richter scale, and the focal depth was . The Central Weather Bureau recorded a total of 12,911 aftershocks in the month following the main tremor. The total energy released is estimated to be 2.1 × 10 J, approximately the same as the yield of the Tsar Bomba. The earthquake was in an unusual location for Taiwan, which experiences the majority of its earthquakes off the eastern coast, such quakes normally causing little damage. One of the aftershocks, on 26 September, was a strong earthquake in its own right,
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