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,
Richter magnitude scale isolated area. Several scales have historically been described as the "Richter scale", especially the "local magnitude" formula_2 and the surface wave formula_3 scale. In addition, the "body wave magnitude", formula_4, and the "moment magnitude", formula_5, abbreviated MMS, have been widely used for decades. A couple of new techniques to measure magnitude are in the development stage by seismologists. All magnitude scales have been designed to give numerically similar results. This goal has been achieved well for formula_2, formula_3, and formula_5. The formula_4 scale gives somewhat different values than the other scales. The reason for so many different ways to measure