This study continues a series of annual brief reviews on the seismic activity in the southern part of the Russian Far East, based on the data from the catalog of the “Yuzhno-Sakhalinsk” Regional Information Processing Center, part of the Sakhalin Branch of the Federal Research Center “Geophysical Service of the Russian Academy of Sciences” (SB FRC GS RAS). The main seismic parameters for the study area in 2025 are presented: maps of earthquake epicenters and their maximum macroseismic effects, a statistical estimate of the seismic activity level using the SESL’09 scale, Benioff graphs, and density maps of nominal elastic deformation. On July 29, 2025, a strong earthquake with a magnitude of 8.8 occurred at the junction of the Kuril-Okhotsk and Kamchatka regions. Foreshock and aftershock activity in the focal zone of this earthquake accounted for approximately half of all seismic events in the study area. Brief information on this earthquake is provided, based primarily on the data from the Geophysical Survey of the Russian Academy of Sciences. Brief information is also provided on other significant earthquakes in the southern Far East that are of interest for detailed study. The seismicity level of the Kuril-Okhotsk region in 2025 is estimated to be high; that of the Sakhalin region, average background; and that of the Amur region and Primorye, low background.

Due to methodological changes in the work of the Sakhalin Branch of the Federal Research Center “Geophysical Survey of the Russian Academy of Sciences” (SB FRC GS RAS), it became necessary to clarify the transition relationships between the energy characteristics of earthquakes in the Sakhalin region used for the magnitude unification of the catalog. To obtain the transition relationships, a sample for the period from 2017 to October 2024 was used from the database of the “Yuzhno-Sakhalinsk” regional information processing center, which is a part of the SB FRC GS RAS. Using the generalized orthogonal regression method, the relationships linking the magnitude of crustal (h < 40 km) earthquakes ML and the energy classes KР and KC were calculated, as well as the magnitudes ML and MPVA separately for crustal and deep-focus (h = 250–600 km) earthquakes in the region. The relationship between ML and the magnitude of the Japan Meteorological Agency Mj was also obtained. It was revealed that for shallow Sakhalin earthquakes Mj ≈ ML; for deep-focus earthquakes, an underestimation of the magnitude ML relative to Mj was noted. As the observational data accumulates, it is assumed that the obtained relationships will be refined.

The paper continues the series of annual brief reviews of the seismicity in the southern part of the Russian Far East, based on the data from the catalog of the “Yuzhno-Sakhalinsk” Regional Information Processing Center of the Sakhalin Branch of the Federal Research Center “Geophysical Survey of the Russian Academy of Sciences”. The main parameters of the seismicity of the studied area in 2024 are given: maps of earthquake epicenters and their maximum macroseismic effects, statistical estimate of the seismicity level SESL'09, Benioff graphs, and density maps of nominal elastic deformation. The information on some of the most significant and interesting for detailed study earthquakes is given. Seismicity of the south of the Russian Far East remains moderate in 2024, within the background level. At the same time, there is a reduced level of crustal and upper mantle seismicity (h ≤ 70 km). Almost all major earthquakes in 2024 occurred in the interval of deep earthquakes (h > 70 km). The strongest earthquake with Mw = 6.8 occurred in the middle part of the Kuril Island arc at the depth of h = 182 km.

The paper presents an overview of the seismicity of the southern part of the Russian Far East in 2023 based on the data from the catalog of the “Yuzhno-Sakhalinsk” Regional Information Processing Center (RIPC) of the Sakhalin Branch of the Federal Research Center “United Geophysical Survey of the Russian Academy of Sciences” (SB FRC UGS RAS). The main parameters of seismicity, such as maps of earthquake epicenters and their macroseismic events, the statistical estimation of the seismicity level (SESL'09), Benioff graphs, and density maps of nominal elastic deformation in 2023 in comparison with the previous longer time interval, are given. A brief analysis of the most significant and interesting earthquakes for detailed study is given. The seismicity of the Kuril-Okhotsk, Sakhalin, and Amur and Primorye regions remained moderate during the year, within the background values. The strongest earthquake with Mw = 6.4 occurred in the southern part of the Kuril Island arc.

The Yuzhno-Sakhalinsk Seismological Regional Information Processing Center (RIPC) recently used the Richter magnitude Mwa to estimate the energy level of Far Eastern earthquakes. To date, this is the most common energy characteristic in the operational catalog of the RIPC. The basis is digital waveforms of regional seismic stations emulated to the characteristics of the Wood–Anderson seismograph. In the present paper, the results of determining the magnitude Mwa in Russian Far Eastern conditions are analyzed. The magnitude determination accuracy is estimated, and station corrections are obtained. The regression relation Mwa and Japanese Meteorological Agency magnitude Mj showed a high similarity between these scales. This made it possible to use Mj as the reference when studying the features of Mwa. The regional seismic network makes it possible to correctly estimate the magnitude Mwa at a regional distance (up to about 1000 km), including for deep-focus earthquakes (up to 600 km). Transfer relations between Mwa and other mass-determined regional energy characteristics of earthquakes are obtained. The Mwa scale can be used to estimate the energy level of any earthquakes in the Kuril–Okhotsk and Sakhalin regions in the magnitude range of weak and moderately strong events and is recommended for inclusion in regional earthquake catalogs for the Russian Far East.

A strong earthquake with a magnitude Mw = 7.0 occurred on February 13, 2020, at a depth of 142 km in the vicinity of the Southern Kuril Islands. Over recent decades, there has been an anomaly near the focal zone in the earthquake distribution over the layers of the double seismic focal zone in accordance with the seismic dislocation kinematic type compared to the other areas of the intermediate depths of the southern part of the Kuril arc. Inversion of the earthquake focal mechanisms of intermediate depth was performed for the southern part of the Kuril Islands along the upper and lower layers of the seismic focal zone. In the upper layer, compression prevails along the slab; the axis of maximum compression σ3 is mainly parallel to the slab and is oriented at an angle of 140–160° (320–340°) to the direction of its dip, i.e., subparallel to the Pacific Plate motion vector in the mantle in this area. The stress state of extension along the slab prevails in the lower layer; the axis of minimum compression σ1 is parallel to the slab and is mainly rotated by 20° (200°) clockwise from the direction of its dip. This orientation of the principal stress axes could indicate that, in addition to the slab unbending, their formation is affected by the mantle resistance to its movement. In the upper and lower layers, we marked the areas where the shear stress prevails that correspond to the kinematic type of transform faults, which are presumably seismically active on the descending plate. The most complex pattern of the stress state of the medium was obtained near the focus of the earthquake that occurred on February 13, 2020. Here, in the upper layer, an area with the stress state of extension and orientation of the principal axes corresponds more to the lower layer. Seismic quiescence is observed in the lower layer, near the focus of this earthquake within the area 60 km wide along the island arc and at the entire interval of intermediate depths.

The paper presents an overview of the seismicity of the southern part of the Russian Far East for 2021: Amur–Primorye region, Sakhalin and Kuril-Okhotsk region. It is based on data from the catalog of the “Yuzhno-Sakhalinsk” Regional Information Processing Center of the Sakhalin Branch of the Federal Research Center «United Geophysical Survey of the Russian Academy of Sciences». Regression relationships between the energy characteristics of earthquakes in the catalog are given. The main parameters of seismicity are estimated: statistical estimation of seismicity level SESL’09; Benioff diagrams; density maps of conditional elastic deformation. The information about the most significant earthquakes in the responsibility zone of the SF FRC UGS RAS is given. According to formal indicators, the seismicity of these regions in 2021 was within the background values. The magnitude of the strongest earthquake recorded in the catalog of 2021, which occurred on September 20 within the Kuril-Kamchatka seismofocal zone at a depth of 41 km, was Mw = 6.1. The strongest crustal earthquake in the Sakhalin region with Mwa = 4.4 occurred on April 18 near the settlement of Tymovskoe, where it was felt with an intensity of 5-6 points.

A review of the Amur and Primorye, Sakhalin, and the Kuril-Okhotsk region seismicity for 20162017 is presented on the basis of data from the regional network of stationary seismic stations of the Sakhalin branch of the Geophysical Survey RAS with the involvement of data from adjacent seismological Russian and foreign agencies, as well as ten stations of the local network operating in the south Sakhalin. Parameters of 4561 seismic events have been determined, 114 of them are explosions. Focal mechanisms were calculated for 32 earthquakes. 88 earthquakes have shown a macroseismic effect. A map of the epicenters is presented, the distribution of the number N of crustal and deep-focus earthquakes by a magnitude, a total seismic energy E for seismically active regions of three regions are given, in comparison with the average parameters N and E for 2001-2015. For each region, an analysis of the parameters of the seismic regime in 2016-2017 is given in comparison with long-term averages, the maximum and significant seismic events are described. The seismicity of the Priamurye and Primorye, Sakhalin, and the Kuril-Okhotsk region in 20162017 can be characterized as a moderate one.

The study has been done on the orientation of the principal axes of tectonic stress field at intermediate depths of earthquakes of the southern flank of the Kuril-Kamchatka subduction system separately for the upper and lower double seismic focal zones. Use has been made of the NIED and GlobalCMT catalogue data. The computation-based results are presented on schemes of the stressed state of the investigated areas and in tables. In the context of the southern Kuril Islands, evidence has been provided for predominance of the maximum compressive stresses along the slab plane in the upper layer and minimal compressive stresses (deviation extension) in the lower layer. However, the principal axes of maximum and minimum compression are displaced in direction relative to the slab dip: by 30–40° counterclockwise for the compression axis in the upper layer, which coincides with the direction of plate movement, and clockwise for the extension axis in the lower layer. This might be caused by the right-lateral strike-slip component of the Pacific Plate subduction. Unlike the general trend, the orientation of the principal axes of the stress field beneath the central Hokkaido-related segments in the upper layer is almost identical to that in the lower layer. There have also been found the segments exposed to shear stress, with the most extensive located opposite the northern Kunashir Island and beneath the southern Hokkaido Island. The results obtained for major large groups of clusters show good accordance with those published by other authors. The discrepancies relate primarily to small groups of isolated clusters showing local stress field heterogeneities.

Анализ тенденций развития военно-экономического обеспечения национальной безопасности, показал, что наиболее вероятным вариантом обеспечения горючим соединений, воинских частей и иных организаций округа войск национальной гвардии будет через передачу части функций обеспечения горючим сторонним организациям нефтепродуктообеспечения, обладающей необходимой разветвлённой сетью структурных подразделений во всех регионах. Это, в свою очередь, повлечёт необходимость уточнения, а в ряде случаев и коренного пересмотра функций, выполняемых центральными и окружными органами военного управления службы горючего войск национальной гвардии, с акцентом на совершенствование их деятельности в вопросах размещения государственных заказов на оказание услуг по обеспечению горючим для соединений, воинских частей и иных организаций округа войск национальной гвардии. Цель – Обоснование предельной стоимости логистических операционно-складских работ при формировании первоначальной цены контракта для обеспечения адекватности и обоснованности применяемых в расчётах показателей учитывающие внешние и внутренние экономические факторы. Метод или методология проведения работы: в статье использовались экономико-математические методы, а также статистические методы анализа. Результаты: получены наиболее информативные параметры, раскрывающие вопросы интеграции однородных функций системы материально-технического обеспечения войск национальной гвардии РФ с гражданским сектором экономики. Область применения результатов: полученные результаты целесообразно применять экономическими субъектами, осуществляющими закупочную деятельность, при прогнозировании первоначальной цены контракта на основе имеющихся статистических данных и предлагаемых обоснованных коэффициентов.

A review of the Amur and Primorye, Sakhalin, and the Kuril-Okhotsk region seismicity for 2015 is presented on the basis of data from the regional network of stationary seismic stations of the Sakhalin branch of the Geophysical Survey RAS with the involvement of data from adjacent seismological Russian and foreign agencies, as well as ten stations of the local network operating in the south Sakhalin. Parameters of 1643 seismic events have been determined, 126 of them are explosions. Focal mechanisms were calculated for 62 earthquakes. 48 earthquakes have shown a macroseismic effect. A map of the epicenters is presented, the distribution of the number N of crustal and deep-focus earthquakes by a magnitude, a total seismic energy ∑E for seismically active regions of three regions are given, in comparison with the average parameters N and ∑E for 20012014. For each region, an analysis of the parameters of the seismic regime in 2015 is given in comparison with long-term averages, the maximum and significant seismic events are described. The seismicity of the Priamurye and Primorye, Sakhalin, and the Kuril-Okhotsk region in 2015 can be characterized as a moderate one.

Обсуждается проблема современной геодинамики Дальневосточного региона на основе мониторинга разномасштабных деформаций и сейсмичности в области сочленения Евразийской, Североамериканской, Тихоокеанской, Амурской и Охотской литосферных плит с применением современных методов космической геодезии и широкополосной сейсмологии. Дан краткий обзор этапов развития Единой сети геодинамических наблюдений ДВО РАН, основных результатов сейсмологических и GPS/ГЛОНАСС-наблюдений, полученных в рамках целевой комплексной программы научных исследований ДВО РАН «Современная геодинамика, активные геоструктуры и природные опасности Дальнего Востока России (2009–2013 гг.)» и проектов ДВО РАН 2014, 2018, 2019 гг., а также достигнутых позиций ДВО РАН в области геодинамики. The problem of the recent geodynamics of the Far East region is discussed based on monitoring of different-scale deformations and seismicity in the articulation of Eurasian, North American, Pacific, Amurian and Okhotsk lithospheric plates using modern methods of space geodesy and broadband seismology. We present a brief overview of the development stages of the Unified Network of Geodynamic Observations of the Far Eastern Branch of the Russian Academy of Sciences, the main results of seismological and GPS/GLONASS observations obtained within the framework of the Targeted Comprehensive Research Program of the Far Eastern Branch of the Russian Academy of Sciences for 2009–2013 «Recent geodynamics, active geological structures and natural hazards of the Far East of Russia», Projects of the Far Eastern Branch of the Russian Academy of Sciences (2014, 2018, 2019) and the achievements of FEB RAS in the field of geodynamics.

The article presents instrumental and macroseismic data of the earthquake that occurred on April 12, 2014 in the Primorye Region of the Far Eastern Federal District of the Russian Federation. Primorye refers to areas with a weak of shallow seismic activity. This relatively small magnitude M=4.5 earthquake is a rare occurrence in this region. It caused a significant macroseismic effect over an unexpectedly large area. The highest seismic intensity as large as 5 degrees was observed in the settlements nearest to the epicenter – Mezhgorye, Krylovka and Maryanovka. 36 minutes after the main event, an aftershock was recorded with an epicenter 6.5 km southeast of the main shock location, felt by the inhabitants of the settlement of Krylovka. According to the data obtained, the focal mechanism of the earthquake might be treated as the strikeslip fault type with the nodal planes of the sublatitudinal and sublongitudinal extension. In view of tectonics, the earthquake and its aftershock epicenters might be related to a nameless NW striking fault located near Mezhgorye Settlement and linking the Krylovsky and Chernorechensky faults.

Earthquake focal mechanisms in the Southern Kuril-Kamchatka and Northern Japan subduction zones were analysed to investigate the features of the tectonic stress field inside the Pacific lithospheric plate subducting into the upper mantle. Earthquake focal mechanism (hypocenter depths of more than 200 km) were taken from the 1966– 2018 NIED, IMGiG FEB RAS and GlobalCMT catalogues. The tectonic stress field was reconstructed by the cataclastic analysis method, using a coordinate system related to the subducting plate. In most parts of the studied seismic focal zone, the axis of the principal compression stress approximately coincides with the direction of the Pacific lithospheric plate subduction beneath the Sea of Okhotsk. It slightly deviates towards the hinge zone separating the studied regions. The principal tension stress axis is most often perpendicular to the plate movement, but less stable in direction. This leads to compression relative to the slab in some parts of the studied regions, and causes shearing in others. The hinge zone is marked by the unstable position of the tension axis and high values of the Lode–Nadai coefficient, corresponding to the conditions of uniaxial compression, while the compression direction remains the same, towards the slab movement. Two more areas of uniaxial compression are located below the Sea of Japan at depths of 400–500 km.

This article presents an overview of the seismicity of the southern part of the Russian Far East, comprising Primorsky Krai, Sakhalin and Amur oblasts including Kuril-Okhotsk, based on preliminary data from the earthquake catalogues of the Sakhalin branch of the Federal Research Center "United Geophysical Survey of the Russian Academy of Sciences", obtained in 2019.A brief description of the seismicity of the regions over the past year is provided, showing its level in comparison with the previous years and indicating the strongest and most seismically interesting earthquakes.In terms of seismicity, 2019 was relatively calm in all three regions, with no seismic events of magnitude greater than 6.2.Particular attention is drawn to the reduced level of seismic activity in the middle Kuril Islands.

The review of the Kuril-Okhotsk region seismicity in 2014 is presented. Earthquake parameters were obtained on the basis of the data of the seismic stations of Sakhalin branch GS RAS and the data of neighboring seismological Russian and foreign agencies. 83.6 % of earthquakes are located within the depth interval of h80 km, 13.5 %  within the intermediate layer h=81–300 km, 2.9 % of earthquakes have depths h>300 km; the maximum depth of the hypocenter was h=559 km. The analysis of the seismic situation in 2014 in comparison with the data for 2001–2013 is carried out, a description of the seismic situation in seismically active regions is given. For 30 earthquakes information was obtained on the macroseismic effect in Russia, the maximum intensity did not exceed Ii=5; for 50 earthquakes there was information on the intensity in the territory of the Japanese Islands, the maximum value was Ii =67 by the MSK-64 scale. The strongest earthquake in the region occurred in the central part of the Sea of Okhotsk on September 18 at 04h17m with h=529 km and MSH=6.2. Its focal mechanism is classified as an incision with a small right-lateral strike-slip component along a subvertical plane of north-eastern strike. The seismicity of the region in 2014 can be considered as a moderate, the number of earthquakes with a magnitude MP≥4.5 and their total seismic energy do not exceed the average values over a 13-year period, the level of seismicity of the region according to the SOUS’09 method is classified as а “background average”. The distribution of earthquake hypocenters and their focal mechanisms show that most of the earthquakes in the Kuril-Okhotsk region relate to the process of the subduction of the Pacific lithospheric plate under the Okhotsk Sea plate.

On November 25, 2013, at 03:23 UTC, an earthquake with a magnitude of МwGCMT=5.2 was recorded in the Laperuz Strait water area. This earthquake was the strongest in the south of Sakhalin Island in 2013. Parameters of the earthquake have been determined by data of seismic stations of the regional network of GS RAS Sa-khalin branch, seismic stations of global network IRIS (GSN) and Hokkaido University. Earthquake parameters on data of regional network are in accordance with data of the international seismological centers. The intensity of concussions in some areas of Sakhalin was 4–5 points on a scale of MSK-64 and 3 points on the JMA scale on the island of Hokkaido. The focus shift has happened under conditions of close horizontal compression, seismodislocation type – uplift. The earthquake of 2013 has arisen in the place of regional tec-tonic structures contact – breaks of West Sakhalin and Central Sakhalin. The seismic model was described by data of local network of field stations. Results of observations of an earthquake on November 25, 2013 are written in this article.

The article contains a description of the seismicity of the Amur region, Primorye, Kuril-Okhotsk and Sakhalin regions in 2018.The paper shows the modern registration capabilities of the Sakhalin branch of the Federal Research Center United Geophysical Service RAS (SF FRC UGS RAS), Yuzhno-Sakhalinsk.We describe the strongest earthquakes most felt by the inhabitants of the region.The focal mechanisms of strong events are presented, and assumptions about the nature of their source are made.It is shown that seismicity in 2018 for the territory of the Sakhalin branch of the FRC UGS RAS was relatively calm, although somewhat more remarkable in comparison with the last decade.It differs only in the area of the northern Kuril Islands, where seismic activity in 2018 was higher than the long-term average level.

In July 2012 – November 2013, a series of strong earthquakes occurred near Urup Island (Kuril Islands, Russia). The article analyzes the position of earthquake foci, focal mechanisms, and macroseismic information according to the SF FRC UGS RAS and IMGiG FEB RAS. The entire set of events according to the epicenter and the mechanisms of the source is divided into a swarm of interplate earthquakes in the immersion zone of the Pacific lithospheric plate with a magnitude up to Mw=6.0 and a stronger and deeper event inside the submerged plate with a magnitude Mw=7.0.

The review of seismicity of Amur and Primorye in 2013 according to the data of permanent seismic sta-tions’s network of the Sakhalin branch of the GS RAS is presented. Maps of the representative registration of earthquakes (Mmin), of epicenters of earthquakes and explosions are presented. Distributions of shallow earthquakes by T.G. Rautian energy classes КR, and of deep-focused by magnitude MPVA are shown; total amount of seismic energy released in six seismoactive areas is given. The results of observations of after-shock activity of Skovorodino earthquake on October 14, 2011 (M=6.2) are presented. Seismicity recorded in 2013 is compared with the results of long-term observations. In general, the seismic regime of the Pri-amurye and Primorye region in 2013 is identical to that in 2012. The Turano-Bureinsky district (No. 4) con-tinues to be the dominant region in terms of released seismic energy of crustal earthquakes, which is similar to the previous year. The more stable operation of seismic stations in 2013 had a positive effect on the quality of seismic events in the catalog. There is a noticeable shortage of small events in the catalog (with КР≤6.5) despite this. This is mostly relevant to Stanovoy District No. 1 and Yankan-Tukuringra-Dzhagdinsky No. 2 regions. There was a significant increase in the total amount of released seismic energy of deep-focus earthquakes in the Sikhote-Alin area No. 5 in 2013. The peculiarity of 2013 was a slight in-crease in the number of recorded technogenic events, the largest of which are located on the territory of northern China. In most parts of the Amur and Primorye region the level of seismic activity in 2013 re-mained moderate.