The objective of this study was to create a representative earthquake catalog for the Eastern Sector of the Arctic zone of the Russian Federation that combines all available data from Russian and international seismological agencies, with magnitude reduction to a uniform scale. The article describes the catalog compilation algorithm, as well as formalized procedures for removing duplicates and choosing the optimal magnitude scale. Due to different network configurations and record processing methods, different agencies may register/miss different events. This results in the absence of some events in different earthquake catalogs. Therefore, merging the data of various seismological agencies will provide the most complete catalog for the studied region. When merging catalogs, the problem of identifying duplicates (records related to the same seismic event) necessarily arises. An additional difficulty arises when distinguishing between aftershocks and duplicates since both are events that are close in space and time. To solve this problem, we used a modified nearest neighbor method developed earlier by the authors. The modified version, which is focused on identifying duplicates and distinguishing between duplicates and aftershocks, uses a probabilistic metric in the network error space to determine the epicenters and times of seismic events. In the present paper, a comparison and regression analysis of the different magnitude types of the integrated catalog is carried out, and based on the obtained ratios, the magnitude estimates are unified.

The average relationship is established between the basic magnitude for the Kamchatka regional catalog, M L, and modern moment magnitude Mw. The latter is firmly tied to the value of the source seismi

The article is a continuation of the research on creating the most complete and representative earthquake catalogs by combining all available data from regional, national, and international seismological agencies and reducing magnitudes to a uniform scale. The task of identifying and removing duplicates that arise during the merging process is solved using the authors’ modification of the nearest neighbor method. It is evident that the intelligent merging of different earthquake catalogs for the same territory will improve the completeness and representativeness of events in the final integrated catalog. In this article, the earthquake catalog of the western sector of the Arctic zone of the Russian Federation (AZRF) covering the period 1962–2022 was created by merging three regional Russian catalogs and the ISC catalog. The ratio of magnitude types in the catalog for different seismic networks was analyzed, and magnitude estimates were unified based on the obtained ratios. For analyzing seismic activity in the western AZRF, it is recommended to use earthquakes from the period 1998–2020 when the catalog was significantly cleaned from explosions and other events of the “non-earthquake” type.

—A joint analysis of seismicity in the Baikal Rift Zone (BRZ) is carried out using modern instrumental data (Baikal Branch of the Federal Research Center “Geophysical Survey of the Russian Academy of Sciences,” 1963–2021) combined together with historical and paleoseismological data on earthquakes. The structure of the seismicity field within BRZ is studied by the new statistical methods. The spatial resolution in the seismically active areas attained 100–120 km. The analysis revealed patches of seismic activity alternating with areas of relative seismic quiescence (seismic gaps). The seismic patches form a hierarchical structure. At the highest level (a spatial scale of 500–1800 km and a lifetime of 300 years and longer), three main patches of seismicity are identified within BRZ, defining the Sayan, Baikal, and Severomuiskii (North Muya) subregions. Smaller patches form a structure with a spatial scale of 100–500 km and a lifetime of 50–200 years. The patches of seismic activity reflect the segmentation of active faults during the seismotectonic evolution of the Earth crust. The estimates of the maximum regional magnitude M_max from instrumental data for 1963–2021 and from seismogeological data are compared. It is shown that quantile estimates Q_q(T) of the maximum earthquakes in the future time interval T are preferable to the M_max estimates for the seismic risk problems.

This paper continues the series of publications by the authors on the recognition of areas prone to the strongest, strong, and significant earthquakes using the FCAZ system-analytical method. The areas prone to earthquakes with M ≥ 5.5 in the eastern sector of the Arctic zone of the Russian Federation were recognized. It is shown that certain potential high seismicity zones are well confined to the boundaries of the Eurasian, North American, and Okhotsk tectonic plates. In addition, according to the results of the FCAZ recognition, some areas located at a sufficient distance from the main tectonic structures of the studied region were also recognized as highly seismic. The results of the study, among other factors, justify the use of the assessment of the completeness magnitude in the catalog for choosing the set of recognition objects for the FCAZ method.

This paper is devoted to the review of currently functioning seismological agencies, seismic monitoring networks created, developed and supported by them, as well as earthquake catalogs produced. Particular attention is focused on international and national seismological centers and seismic networks. A historical insight about the first observations made by seismic networks completes the picture. The basic parameters of the main seismic networks and the principles of functioning for seismological centers are considered. The key characteristics of seismic catalogs that determine the criteria for their quality are discussed. The system-analytical approach to solving the urgent problem of creating the most complete and representative earthquake catalogs with a unified magnitude scale by integrating data from international, national and regional catalogs in the studied region is presented.