Historical Seismograms - Evidence from the AD 2000 Izu Islands ...

~~120Deli Cheng, Yushou Xie, and Zhifeng DingMS6.56.05.55.0./: .4.55 5.5 6.0 6.5 MHFigure 4. Ms vs. MH (Hsu) curve of Taiwan earthquakes (1936-1948).4. Results and DiscussionThe magnitudes of the 1,006 Chinese earthquakes that occurred between 1900and 1948 were calculated, checked, or extrapolated, according to the given G-R magnitudescale, the data analysis method and magnitude determination. The revisedmagnitudes were listed in the fourth volume of Compilation of Historical Materialsof Chinese Earthquakes (Xie and Cai, 1985-86). Table 2 lists the parameters forearthquakes with Ms (or nag) 2 6.5, together with their magnitudes from severalpopular catalogues for comparison.4.1. Figure 6 shows the statistical comparison of our unified magnitudes with thosegiven in several other catalogues. The magnitude values listed in this paper agreewell with that in Gutenberg’s table (1954), with a mean deviation = +0.01 and0 = * 0.11. This deviation seems to be related to the fact that supplementary datawere added and formula (3) was used in the treatment of data from near stations. In__comparison with Abe’s results (1981, 1983a), AM = +0.02, with IT = f0.06. Ourmagnitude is a little higher than that given in New Catalogue - of Strong Earthquakesin the USSR (Kondorskaya and Shebalin, 1977), with AM = -0.08 and IT = k 0.15;and differs most from that of Atlas of Earthquakes in USSR (Savarenskii et al.,1962)) with = -0.27 and (T = & 0.22.