[S-SS03] New insights in Earthquake predictability: modelling and forecasting

[SSS03-P02] Nonstationary Renewal Model for Forecasting Repeating Earthquakes under Aftershock-Triggering Effects

*Shunichi Nomura¹, Masayuki Tanaka² (1.The Institute of Statistical Mathematics, 2.Meteorological Research Institute)

Keywords:Recurrent earthquakes, Renewal processes, ETAS model

The point process models to predict earthquake occurrences are roughly classified into two types except for the simplest Poisson process; one is the renewal process for repeating earthquakes and the other is the ETAS (Epidemic-type aftershock sequence) model taking the aftershock-triggering effect of every earthquake into account. However, relatively small repeating earthquakes have the characteristics of both models such that they usually recur periodically but their recurrence intervals get much shorter after nearby large earthquakes. We propose a nonstationary renewal process model for such repeating earthquakes that incorporates the aftershock-triggering effect of nearby large earthquakes as a relative change in the loading rate. We apply the proposed model to the repeating earthquake catalog on Pacific Plate subduction zone in the northeastern Japan and evaluate probabilistic forecasts of the next repeating events considering the aftershock-triggering effect of the 2011 Tohoku earthquake.