Abstract: Pattern informatics(PI) method is a new way to forecast earthquake based on statistical physics, which has seen great development in recent years. In this paper, this method, combined with the method of density at grid nodes of seismic activity, which is used to study the prediction of long-term prediction in north China. The probibilitic results of future seismic evaluation of the occurrence of M_L≥5.0 earthquakes has been shown based on the data of M_L≥3.0 events in earthquake catalog from 1970 to 2011, time window of 16 years, 3 years of “anomalous investigation” and “prediction time term” and combinated with some factors, such as earthquakes numbers in the space-time and magnitude range and distribution of the events. The statistic investigation for the prediction ability is shown by Molchan chart method. It is shown that this combined method is better than PI method in some aspects and could be applied in the analysis of the future seismicity and middle to long term prediction.

Key words: Pattern informatics, Earthquake space concentration, Long-term earthquake forecast, Molchan test