Analysis of Spatial Clustering of Seismic Events Using DPS Topological Filtering Algorithm: Baikal Region

Abstract—The paper presents the results of applying the Discrete Perfect Set (DPS) topological filtering algorithm to analyze the spatial clustering of seismic epicenters in the Baikal region. The study in based on the earthquake data recorded by the seismic network of the Baikal Branch of the Geophysical Survey of the Russian Academy of Sciences in the region between (48° N, 58° N) and (99° E, 122° E) from 1964 to 2018. Clustering characteristics are obtained for (i) the recording period from 1989 to 2018 with different parameters of the DPS algorithm and four levels of the minimum energy class K_Р of seismic events and (ii) six nonoverlapping time intervals from 1964 to 2018 and seismic events of energy class K_Р ≥ 8.6 with fixed parameters of the DPS algorithm. The dynamics of the clustering parameters from 1964 to 2018 possibly characterizes the variability of seismicity in the region. Namely, the decrease in the linear size of the identified groups of epicenters from about a thousand km to tens km may indicate a significant change in seismic activity in the Baikal region at the end of the 1990s and the beginning of the 2000s compared to the period between 1964 and 1997.