Methods for Assessing the Seismic Hazard of Stable Continental Areas Using Combined Paleoseismological and Geophysical Data

Assessing the seismic hazard of stable continental areas, where modern seismic activity is insignificant, is a complex task that needs to be solved in order to ensure the safety of people and buildings in these territories. Traditional methods, including seismotectonic research, seismological monitoring, identification of seismic source zones (SSZs), and subsequent hazard assessment, are ineffective in such areas due to the lack of representative earthquake statistics and low informativeness of the data. In the seismic zoning of such areas (especially for solving seismic safety problems for critical objects, such as nuclear power plants), one cannot limit oneself to modern seismicity data: it is necessary to take into account rare seismic events, i.e., earthquakes with a large recurrence period. The joint study of active faults, earthquakes of historical record, and paleoearthquakes can significantly extend the time range of a strong-earthquake catalog and make it possible to identify new, previously unidentified SSZs. To assess the seismic hazard of territories in stable continental regions, the authors of this article propose using paleoseismological data together with the results of seismological and geophysical studies, which makes it possible to combine paleoearthquake and modern seismicity data. seismic observations are analyzed to obtain additional information on the stress–strain state of the study area and determine the earthquake focal mechanisms of identified SSZs. The results of geophysical studies make it possible to judge the existence of ancient but still “nonconsolidated” faults in SSZs, which may, in tandem with other research methods, indirectly confirm their correct identification as active. In the article, this approach is used to assess the seismic hazard of Karelia and the Kola Peninsula. The seismic impacts parameters of events with a long recurrence period are evaluated for individual objects and populated areas of this region.