Abstract：Based on the analysis of seismicity characteristics in northeast China, the following conclusions can be obtained: 1) We should make a concrete analysis from the time prosodic characteristics of the seismicity period in northeast China.The duration of the fifth active period, the number of earthquakes and other indicators,all show that the fifth period of seismic activity in northeast China has ended.
The magnitude 5.7 and 5.1 earthquakes in Jilin Songyuan in 2018 and 2019 may mark the beginning of the sixth active period in northeast China. 2)The main seismic areas in northeast China are located in Songliao basin and Greater Khingan range area from 2013 to 2019. The two regions have the activity characteristics of migration pair with the boundary line between Greater Khingan range and Songliao basin. By analyzing the migration trajectories of five groups, it is possible for future earthquakes to migrate to Greater Khingan range region. 3) The boundary between paired earthquakes and unpaired seismicity in northeast China is formed by the southern margin of Songliao basin.Since 1900, paired earthquakes in northeast China have occurred mainly in Songliao basin and Greater Khingan range region.The time interval between the paired earthquakes is 0.1 month to 37.0 months, the distance interval is as far as 309.0 km, and the magnitude difference is up to 0.7.A total of 27 earthquakes with a magnitude of 5.0 or above occurred in the Songliao basin and Greater Khingan range area, among which 24 earthquakes had paired activity and the incidence of paired earthquakes was about 89%.71% of the paired earthquakes occurred in the Songliao basin and 29% in Greater Khingan range region.The law of paired seismic activity is universal in Songliao basin and Greater Khingan range area and can be used as a prediction index. 4) Comparing the results of surface strain rate in northeast China from 2013 to 2015 and 2015 to 2018, the area of the most significant change is located in the middle of Songliao basin, which is also the area with the most significant change in northeast China. There is a risk of future earthquakes in the area. 5) Songliao basin will remain the main area of shallow seismic activity in northeast China.
