Towards a universal rule on the recurrence interval scaling of repeating earthquakes?

A recent analysis of recurrence properties of small repeating earthquakes on a creeping oblique thrust fault in eastern Taiwan reveals a weak variation in recurrence interval (T_r) with seismic moment (M_o). Compared to the scaling of T_r with M_o from repeating earthquake data near Parkfield in California, the repeating data from eastern Taiwan has recurrence intervals that are 2 times shorter. Also in northeastern Japan, T_r of repeating quakes are ∼4 times shorter than those expected from the Parkfield scaling law. When adjusted to account for differences in the geodetically derived slip rates for the three fault zones, however, the T_r-M_o scaling is remarkably consistent among the three regions. It suggests that the tectonic loading rate is likely the most important factor that controls the repeat time. It also suggests that there seems to exist a universal rule on recurrence interval scaling of repeating earthquakes in diverse tectonic settings.