In this study, we measure the seismic radiation energy,,E,, and seismic moment, M-o, of twenty-two larger-sized aftershocks with 5.1 <= M-L <= 6.5 of the 1999 M-s 7.6 Chi-Chi, Taiwan, earthquake from high-quality digital strong-motion data recorded at stations with epicentral distances of less than 50 kin through a method proposed by Andrews (1986). We also eliminate the effects on the measures
... [Show full abstract] of E-s and M-o due to site amplification and finite frequency bandwidth limitation. Comparison of the values of M-o obtained in this study and those listed in the Harvard CMT catalogue shows that Andrews' method to measure M-o from local seismograms is acceptable. The measured values are E-s = 2.0 x 10(18) -8.9 x 10(21) g cm(2) sec(-2) and M-o = 1.3 x 10(23) -1.4 x 10(26) g cm see(-2) cm(-1), which give the scaled energy to be E-s/M-o = 7.4 x 10(-6) -2.6 x 10(-4). The scaled energies of the 22 events are dependent upon earthquake magnitude, M-s, when both E-s and M-o are evaluated from local seismograms; yet, independent of M-s when M-o is estimated from teleseismic data. Scaled energy slightly depends on the depth, h (in km), through the following form: E-s/M-o = 1.92 x 10(-5)e(0.09h). In addition, the corner frequency, f(c), is also measured. Its value ranges from 0.15 to 1.34. The scaling law between M-o and f(c) is: M-o similar to f(c)(-3.65).