Spatial and statistical analysis of seismic energy distribution in the Olekmo-Stanovoy seismotectonic zone (South Yakutia)

The seismic activity in the Republic of Sakha (Yakutia) is monitored across a vast territory of 1.5 million km² and is characterized by two major seismic zones of varying rank: the Olekmo-Stanovoy seismotectonic zone in the south andthe Arctic-Asian seismic belt in the north. This article explores the Olekmo-Stanovoy seismotectonic zone, which forms the eastern flank of the Baikal-Stanovoy seismic belt. For statistical analysis, we used a geological and geophysical model of the Southern Yakutia territory. According to this model, the Olekmo-Stanovoy seismotectonic zone is segmented into five structural-tectonic blocks. For the study area, we compiled a regional catalog of earthquakes, supplemented by data from the International Seismological Bulletin (ISC). Based on the seismotectonic features and geodynamic position of the region, a spatial-statistical analysis of seismic energy released during earthquakes over a 58-year instrumental period of regional seismological observations was conducted. The main parameter for calculations was the parameter ΣE (total released seismic energy), which is most often used in the comprehensive quantitative assessment of seismic activity in a region. This study examines the major earthquakes that made the largest contribution to the calculations of the total energy released in each of the five blocks. Analysis of seismic-statistical data collected in the aisles of large structural-tectonic blocks of the first rank revealed the following correlation: in the Olekmo-Stanovoy seismotectonic zone in the direction from west to east, with distance from the Baikal rift zone, seismic activity decreases by 104 times. This thesis also suggests a slowdown in the intensity of seismotectonic and geodynamic processes in the same direction. The results of spatial-statistical analysis of the distribution of seismic energy in large regional blocks of the Olekmo-Stanovoy seismotectonic zone can be relevant for conducting small-scale research to assess the potential seismic activity of poorly studied areas and for medium-term earthquake forecasting as an independent indicator of impending seismic events.

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