Abstract
The statistical distribution of earthquake magnitude is governed by the well-known Gutenberg-Richter (G-R)law. The seismogenic fault-length is transformed through the Matsuda formula into earthquake magnitude. The statistical distribution of the magnitude such transformed can also be governed by the similar law. On the basis of the list of active faults in Japan, we derive two kinds of statistical distribution formulas of seismogenic fault-length, which are consistent respectively with the modified G-R formula and with the Makjania formula.
