abstract
Regional relationships between earthquake magnitude and rupture length have been determined for different parts of the world based primarily on aftershock data. It appears from this study that a given rupture corresponds to an earthquake of different magnitude in different regions. The correlation between rupture length and magnitude is high for each region, and the noted scatter in such data for a given rupture is consistent with separation between extremes. This suggests that the scatter in worldwide data may be due to regional differences. Assuming that stress and stress drop are constant, the regional difference in magnitude for a given rupture can be interpreted in terms of regional variation in seismic efficiency. Furthermore, data suggest that seismic efficiency in a region is dependent on rupture length or magnitude.
