Spatial variation of seismic moment release before strong and intermediatestrength earthquakes in the fifth seismicactivity period of northeastern China region

To investigate whether the accelerating moment release (AMR) appeared before strong and intermediate-strength earthquakes, related to earthquake preparation process, or not, this study carried out a spatio-temporal scanning over them value, denoting AMR level, derived from the seismic activity in the fifth active period of northeast China region. By referring other studies the spatiotemporal windows of mvalue scanning for searching AMR before MSge;5 earthquakes were determined. For the earthquake data during the 5 months before each MSge;5 earthquake a monthly spatial scanning was performed, and the temporalmvariations before theMSge;5 earthquakes were obtained. The result indicates that AMR appeared before the 4 earthquakes out of the 5 studied cases. The same scanning were performed to search for precursory variation of Benioff strain release around the rupture nucleation point before the strong and intermediatestrength earthquakes. The result shows that accelerating Benioff strain release emerged before 3, out of 5, MSge;5 earthquakes studied.