11:30 AM - 11:45 AM
[SSS14-16] Physics of earthquake triggering: effect of stress perturbation to slip acceleration
To understand such sensitivities to stress perturbation in a unified point of view, here we analyze the rupture nucleation process on a fault subject to weak periodic stress modulation. Assuming the rate- and state-dependent friction law with one state variable, we calculate the threshold amplitude above which the rupture initiation exhibits correlation with the perturbation phase. It is found that the crack-like nucleation is more sensitive to the perturbations than the patch-like nucleation. The estimated threshold amplitude for the crack-like nucleation is significantly lower than the tidal stress change. Time-to-failure for the both nucleation types in the presence of perturbation is estimated, and it is not significantly affected by the stress perturbation. We also discuss the optimum frequency at which the correlation is enhanced.