Real-Time Foreshock Probability Forecasting Experiments in Japan, Southern California and Whole Globe

Tuesday, 16 December 2014
Yosihiko Ogata, Inst Statistical Mathematics, Tokyo, Japan
I am concerned with whether currently occurring earthquakes will be “foreshocks” of a significantly larger earthquake or not. When plural earthquakes occur in a region, I attempt to statistically discriminate foreshocks from a swarm or the mainshock-aftershock sequence. The forecast needs identification of an earthquake cluster using the single-link algorithm; and then the probability is calculated based on the clustering strength and magnitude correlations. The probability forecast model were estimated from the JMA hypocenter data of earthquakes of M≧4 in the period 1926-1993 (Ogata et al., 1996). Then we presented the performance and validation of the forecasts during 1994 - 2010 by using the same model (Ogata and Katsura, 2012). The forecasts perform significantly better than the unconditional (average) foreshock probability throughout Japan region. The frequency of the actual foreshocks is consistent with the forecasted probabilities. In my poster, I would like to discuss details of the outcomes in the forecasting and evaluations. Furthermore, I would like to apply the forecasting in California and global catalogs to show some universality in the forecasting procedure.


[1] Ogata, Y., Utsu, T. and Katsura, K. (1996). Statistical discrimination of foreshocks from other earthquake clusters, Geophys. J. Int. 127, 17-30.

[2]Ogata, Y. and Katsura, K. (2012). Prospective foreshock forecast experiment during the last 17 years, Geophys. J. Int., 191, 1237–1244.