3:45 PM - 4:00 PM
[SCG53-32] Tidal effects on seismic activity and rupture nucleation process
Keywords:earthquake nucleation process, tidal response of seismic activity
To understand such sensitivities to stress perturbation from a unified point of view, here we analyze the rupture nucleation process on a fault plane subject to weak periodic stress modulation. Assuming the rate- and state-dependent friction law with one state variable, we calculate the seismicity rate as a function of the perturbation (tidal) phase and the threshold amplitude of stress perturbation above which the seismicity correlates with the stress perturbation. The estimated threshold amplitude is comparable to the tidal stress change. Time-to-failure is also estimated, and it is not significantly affected by the stress perturbation. We also discuss the optimum frequency at which the correlation is enhanced.