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It is reported that 41 stationary seismic stations, 2 arrays, and 7 temporary seismic stations, located in the area of Novovoronezh and Kursk nuclear stations, monitored seismicity of the Russian territory of the East European Platform (EEP) in 2015. The registration capabilities of the seismic network at the EEP as a whole were estimated based on the average station noise level and the equation for the energy decay of seismic phases. Zones with the best capabilities have been allocated. A feature of seismicity in 2015 is the manifestation of earthquakes of moderate magnitudes (ML=2.7–3.9) in the peripheral regions (in the southwest, west, and northwest) and in zones associated with paleorift structures: in the southwest – with the Dnieper Donetsk and in the northeast – with the Kirov-Kazhim and Soligalich (Central Russian) aulacogenes. The results of the macroseismic survey are given for the earthquake in Poltava on February 2, 2015, with M=3.7; focal mechanisms of two earthquakes (03.02.2015 and 12.06.2015) are constructed. According to the data of the Latvian Center, an earthquake was recorded in the region of Lithuania bordering the Kaliningrad region. Weaker natural seismicity with ML≤2.5 was recorded in Karelia and the regions bordering with Finland, near the Kandalaksha Bay, near the Khibiny, and Lovozersky massifs on the Kola Peninsula, and on the territory of the Voronezh crystalline massif.

We review historical earthquake research in Northern Europe. 'Historical' is defined as being identical with seismic events occurring in the pre-instrumental and early instrumental periods between 1073 and the mid-1960s. The first seismographs in this region were installed in Uppsala, Sweden and Bergen, Norway in 1904-1905, but these mechanical pendulum instruments were broad band and amplification factors were modest at around 500. Until the 1960s few modern short period electromagnetic seismographs were deployed. Scientific earthquake studies in this region began during the first decades of the 1800s, while the systematic use of macroseismic questionnaires commenced at the end of that century. Basic research efforts have vigorously been pursued from the 1970s onwards because of the mandatory seismic risk studies for commissioning nuclear power plants in Sweden, Finland, NW Russia, Kola and installations of huge oil platforms in the North Sea. The most comprehensive earthquake database currently available for Northern Europe is the FENCAT catalogue covering about six centuries and representing the accumulation of work conducted by many scientists during the last 200 years. This catalogue is given in parametric form, while original macroseismic observations and intensity maps for the largest earthquakes can be found in various national publications, often in local languages. No database giving intensity data points exists in computerized form for the region. The FENCAT catalogue still contains some spurious events of various kinds but more serious are some recent claims that some of the presumed largest historical earthquakes have been assigned too large magnitude values, which would have implications for earthquake hazard levels implemented in national building codes. We discuss future cooperative measures such as establishing macroseismic data archives as a means for promoting further research on historical earthquakes in Northern Europe.

Information on seismic monitoring in the East Baltic region for 2016–2017 is presented. During this period of time, several tectonic earthquakes occurred, the epicenters of which are located in the north and northwest of Estonia and in the area of Lake Võrtsjärv. The territory of Estonia and the adjacent waters of the Baltic Sea are still the most seismically active parts of the East Baltic region. Attention is drawn to the inherited nature of seismicity, i.e. in the areas of modern earthquakes, earthquakes had already occurred before the instrumental period. Another feature of several earthquakes in the East Baltic region is their association with meteorite craters, which are most often found in the East Baltic region in Estonia and near it, in the Baltic Sea. As before, the bulk of seismic information is associated with man-made explosions in industrial quarries and in the Baltic Sea. The identification of earthquakes of small magnitude remains an urgent problem.

The article concerns results of studying two significant seismic events — an explosion (23.09.2020 09:00) and an earthquake (30.09.2020 20:00), which occurred in the area of the city of Kryvyi Rih. There were developed algorithms to process records by the Kryvyi Rih seismic station. There was done a comprehensive interpretation of the seismologic and geological-geophysical data. The seismic events’ coordinates were determined, the quality of seismological data processing was evaluated based on the expert method, the level of trustworthiness of the resulting parameters was estimated. The nature of the eathquake’s origin was analyzed based on the shape and the records’. The structure of the mechanism of the earthquake center shows that this was a natural seismic event of the induced type. The article also provides results of geotectonics study of the region of its origin and shows the connection of the geological structures with the epicenter’s parameters. The parameters of the stress-strain state of the crust in the Kryvyi Rih iron-ore basin are calculated, and the parameters of the epicenter of the induced earthquake (2020.09.30 20:00:40.836, UTC) are established. The experimentally calculated depth of the epicenter of local earthquake coincides with the hypothetical depth of 15 km at the lower edge of faults according to the model of the distribution of the depths of the earthquake hypocenters on the Eastern European platform. The proposed methods and algorithms open new opportunities for modern geophysical research in the long-term seismic hazard assessment of Kryvyi Rih. Meanwhile, for a more precise determination of the place, time and nature of local seismic events in the area it is necessary to develop, here and on adjacent territories, a network of seismic stations capable of recording events of comparable and lesser magnitude.