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We present the results of statistical simulation for the seismicity within the zone of interaction among the Amur, Eurasian, and Sea of Okhotsk plates where our seismological analysis revealed the Ole kma-Stanovoi seismic area, the Tan Lu zone, and the northern Sakhalin-Japan island arc. We discuss the spatial irregularities in the seismicity maxima distribution in annual cycles. It was found that when considered in clusters that are ordered over longitude, the seismicity maxima form long chains of anomalies. It is shown that the mean migration rate of seismicity maxima does not vary throughout the east-west trending Olekma-Stanovoi and the Tukuringra-Dzhagdy seismic zones that travel from the north-south eastern framing of the Amur plate as far as the east-west Tukuringra-Dzhagdy seismic zone. We determined the period of spatial synchronization of seismicity in annual cycles. Considered in the framework of a wave model that is assumed for the dynamics of seismicity, we show that the seismic activity in annual cycles can be initiated due to the modulation of seismicity by an external periodic force loading.

Abstract. Based on the statistical analysis of spatiotemporal distribution of earthquake epicenters and perennial geodetic observation series, new evidence is obtained for the existence of slow strain waves in the Earth. The results of our investigation allow us to identify the dynamics of seismicity along the northern boundary of the Amurian plate as a wave process. Migration of epicenters of weak earthquakes (2 ≤ M ≤ 4) is initiated by the east-west propagation of a strain wave front at an average velocity of 1000 km yr −1 . We have found a synchronous quasi-periodic variation of seismicity in equally spaced clusters with spatial periods of 3.5 and 7.26 • comparable with the length of slow strain waves. The geodetic observations at GPS sites in proximity to local active faults show that in a number of cases, the GPS site coordinate seasonal variations exhibit a significant phase shift, whereas the time series of these GPS sites differ significantly from a sinusoid. Based on experimental observation data and the developed model of crustal block movement, we have shown that there is one possible interpretation for this fact that the trajectory of GPS station position disturbance is induced by migration of crustal deformation in the form of slow waves.