Abstract
In our previous report (Jour. Seis. Soc. Japan, 2nd Series, Vol. 2, No. 2 (1949), it was stated that the area of aftershock region (Akm2) and the radius of sensibility circle (Rkm) of several earthquakes in Japan were closely related with each other. Recently, we were able to collect more examples (cf. Table 1 and Figs. 1-9) and investigated these data together with those already reported.
From 12 land shocks and 9 oceanic shocks, we obtained the following relations:
log10A=(1.50±0.07)+(3.16±0.10)R×10-3 for land shock,
log10A=(2.13±0.10)+(2.86±0.13)R×10-3 for oceanick shock, which well support our previous results. (cf. Fig. 10.)
If the radius R of the Great Kwanto Earthquake of September 1st, 1923 be assumed as 700km, instead of 900km., the former formula becomes
log10A=(0.87±0.13)+(4.67±0.19)R×10-3
According to Prof. H. Kawasumi the latter relation is more preferable.
