Process and trend of great earthquakes in the globe and main zones

Based on the qualitative analysis of the seismicity characteristics in the globe, circum-Pacific seismic belt, low latitude circum-earth zone and the great triangle region (Western China continent and its surroundings), we calculated the periodic components using Morlet wavelet transform and evaluated the current earthquake risk by the Nowcasting method quantitatively. Some results are as follows: (1) The most significant periodic component of the global seismicity is 48.6-year and the earthquake potential score EPS of M-w >= 8.5 shocks is about 0.91. The active period of large earthquakes dating from 2004 may last and there is high risk of earthquakes with M-w >= 8.5. (2) The most significant period of the circum-Pacific seismic belt is 48.6-year and its temporal characteristics of large earthquakes are generally consistent with that of the globe. The earthquake potential score EPS of M-w >= 8.5 shocks is about 0.91. The duration time of the active period of M-w >= 8.5 earthquakes is still short and it will continue. The risk of shocks with M-w, 8.5 is high. ((3) The significant period of the low-latitude circum-earth zone is 33.1-year, which reflects the activity of earthquakes with M-w >= 8.0. And the EPS value for M-w 8.0 shocks is about 0.46. The active period beginning from 2004 may tend to end, and the risk of M-w >= 8.0 shocks in the next 10 years is lower. CD The main periodic of the great triangle region is 23.4 year, which reveals the temporal characteristics of the M-s >= 7.8 earthquakes. The EPS value for M-s >= 7.8 events is 0.72. Since 2001, earthquakes with M-s >= 7.8 have been active, and the active state is similar to that in the first 50 years of the 20th century. After the 2015 Hindu Kush M-s 7.8 earthquake, the great triangle region may enter a relatively quiet period of M-s >= 7.8 earthquakes, which may last for 7 similar to 12 years. In the next few years, there is a possibility for M-s >= 7.8 shocks, but the risk is small.