Abstract: We re-sorted systematically seismicity pattern anomalies before 246 earthquakes (M≥5.0) according to Earthquake Cases in China (1970—2013), studied statistical characteristics of seismic gaps and seismic belts combined with regional differences. Our results show that, firstly, in these 246 earthquake cases, the number of seismic gaps and seismic belts before the earthquakes is 105 and 51 respectively, which account for 42.7% and 20.7% of the total earthquakes respectively. Secondly, the ratio of the seismic gaps and seismic belts appears to increase with the increase of main shock magnitude. Especially for earthquakes with M≥7.0, seismic gaps appeared before 83.3% earthquakes and seismic belts before 66.7% earthquakes, which indicate that seismic gap and the seismic belt maybe strong signals of earthquake with M≥7.0. In the whole of Chinese mainland and offshore area, there is a linear relationship among the duration time, distribution scale, initial magnitude of seismic gap and seismic strip, and the main shock magnitude, the correlation coefficient can pass the 95% confidence level threshold test. The statistical results of different tectonic divisions have large differences. The linear relationship between the parameters of seismic gap and seismic belt and magnitude of the main shock can pass the threshold value test apart from the duration time of seismic belt in the northern part of the Tibetan Plateau. Only a few parameters pass the threshold value test in the south section of the North-South Seismic Belt and north China, and all parameters in the Tianshan Mountains cannot pass the threshold value test.

Key words: Seismic gap, Seismic belt, Statistical characteristics, Earthquake Cases in China