资源环境科技发展态势分析平台

The period T-r of repeating earthquakes scales as Vc-1M01/6,Vc being the creep rate of the fault and M-0 the seismic moment of the events. Models consisting of a single asperity embedded in a creeping fault capture this scaling but fail to explain the variability in recurrence time observed during natural sequences. Here I show by a statistical analysis of repeating earthquakes generated in a rate-and-state fault model, that the observed scaling and variability in T-r are reproduced if a population of asperities is considered. For that, the density of asperities needs to be smaller than a critical threshold allowing system-size ruptures. Creep mediated stress transfers control the variability in T-r in this regime, which increases with asperity density. Beyond that density, the seismicity is highly clustered leading to moment-independent recurrence. The dynamics of repeating earthquakes could therefore be an indicator of the amount of seismogenic asperities on creeping faults.