Supporting Data for: Do large earthquakes occur at regular intervals through time? A perspective from the geologic record.

Abstract

We analyzed a catalogue of 31 published earthquake chronologies to assess the commonality of quasi-periodic earthquake recurrence across a range of fault types and tectonic settings. The statistical approach we employ differs from previous methods in that it explicitly incorporates numeric uncertainties in the examined earthquake chronologies, while recognizing that random sequences of events (against which the chronologies are tested) may appear to be less disordered over the short time scales typical of most published records. Our results show that 58% of the chronologies support an interpretation of quasi-periodic recurrence (probability of random recurrence < 10%). These include strike-slip, normal, and reverse faults in both plate-boundary and intraplate environments, which exhibit evidence for quasi-periodic recurrence with comparable frequency. We conclude that quasi-periodic failure is likely the norm for faults in the seismogenic crust, and that stress renewal is a first-order control on fault rupture across a wide range of tectonic settings.