Earthquake forecasting by the time series analyses of earthquake source parameters

We collect earthquakes (EQ's) from a focus catalog of Japan Metrological Agency (JMA) for a small mesh region of about 5 degrees and a large region of about 30 by 35 degrees. The online catalogue, which is almost two days behind, has been available to the public since June of 2002. The EQ selection windows are set for magnitude M (larger than Mc) and focal depth only for some small regions (less than 300 km). The value of Mc is dependent of the regional seismicity. For example, Mc is about 3.3-3.5 for small region and Mc is 4 for the large region. We then sequence the source parameters of every EQ in the chronological event order for each region. The EQ source parameters are the epicenter's latitude (LAT) and longitude (LON), focal depth (DEP), inter-EQ time interval (INT) and magnitude (MAG). The findings of our experimental forecasting, started on June 2003 (www.tec21.jp), suggest that the following deterministic forecasting of large EQ (larger than about 6) for small regions is possible as forecasting of typhoons [Takeda, 2003; Takeda & Takeo, 2004]. 1) In months and weeks ahead of time. 2) The date of rupture within a day or two. 3) The hypocenter within about 0.5 degrees in LAT and LON and about 20km in DEP. 4) The magnitude within 0.5. Our physical model of the seismogenesis bases the forecasting. For example, the model can accurately predict the fault width of the large EQ. The model is an extension of so-called brittle-ductile interaction hypothesis envisioned by Aki [2003, 2004]. Furthermore, running sum of INT over some consecutive events shows the temporal state of stress accumulation in the region. This is because chaos analysis of the series finds that the running sum has only three independent dynamical variables, suggesting that they are three principal stress components in the region. Monitoring only the temporal variations of the stress accumulation in the large region is extremely useful in forecasting only the rupture date of major EQ's whose M is larger than about 7 within a day or two day accuracy. Thus, one can extend our time series analyses globally as long as any EQ catalogue similar to that of JMA is available.