Seismic moment rate and recurrence interval of small-size earthquakes from a 3-D perspective

Repeating postseismic event sequences associated with featured variations of the moment magnitude spectrum and recurrence interval have been fruitfully studied by previous researchers. However, similar features of recorded regular earthquakes are much less frequently observed due to their lower event recurrence frequencies and the range or accuracy limits of the employed observation systems. Based on rapidly increasing catalogs of earthquakes with high-resolution epicenter locations made possible in recent decades and combined with three-dimensional (3-D) numerical calculation techniques, we employ a 3-D seismic density sphere method that recognizes the vertical depth as a similar dimension as the horizontal distance to more quantitatively investigate the seismic moment-recurrence interval (M0-SI) relationship in known seismically active regions in Japan. A subset of 49 seismogenic zones of the 1.8 million events collected in fifteen years show that the logarithm of the seismic interval...