Peculiarities of Localization Zones of the Major Earthquakes in the Kuril-Kamchatka Arc

Abstract—The processes occurring during the interaction of crustal blocks in a subduction zone are reflected both in the features of the seismic regime and in the distribution of the major earthquake sources in the study area. In this study, we analyze the peculiarities of localization zones of the major earthquakes of the Kuril-Kamchatka arc based on two catalogs: the regional catalog of Kamchatka Branch, Federal Research Center, Geophysical Survey, Russian Academy of Sciences, and global international catalog of USGS NIEC of the US Geological Service for 1990–2024. Combination of catalogs based on a modified nearest neighbor method allowed us to remove duplicates—repeated earthquakes in initial catalogs—and to obtain a new unified catalog consisting of 52 574 earthquakes. The nearest neighbor method was applied to identify two subsets: independent and spatially and temporally clustered earthquakes, which were further used to analyze the density of seismic events. The obtained regularities were compared with the focal characteristics of the major earthquakes of the subduction zone. The proposed approach allowed us to identify localization zones of potential megaearthquake sources along the Kuril-Kamchatka arc.