Seismic Network of the Southern Segment of the Far Eastern Zone of Russia and Its Potential for Studying Upper Mantle Heterogeneities

Abstract— This paper presents the key characteristics of a digital broadband seismic network in the southern part of the Russian Far East. It is shown that there has been a qualitative leap in the instrumental capabilities of seismic observations in the region over the past 20 years. The modern configuration of the network not only fulfills its primary purpose (monitoring regional seismicity), but also enables the study of structural features in the mantle transition zone (MTZ). Analysis of data from the “Gorny” (GRNR) station using P-receiver functions (PRF) has revealed converted waves from the 410 km and 660 km discontinuities. The observed travel time anomalies can be explained either by lower seismic velocities than those predicted by the IASP91 reference model or by anomalous depths of the MTZ discontinuities.