The high seismic danger for the town and its agglomerations is confirmed by the spatial confinement of the territory of Alagir to the zone of the possible seismic source (PSS) at the intersection of the Vladikavkaz and Ardon regional seismically active deep faults, the catalogue of historical seismic events and modern seismic activity. Starting from 2015, seismic events do not decrease, but on the contrary, their number increases to three events during the day, covering the area of manifestation along the entire expected width of the Vladikavkaz fault from Ingushetia to Kabardino-Balkaria and noticeably concentrating in the Ossetian sector of the fault. Three earthquakes on the same day were noted near Alagir in 2015; seismic events in this territory were recorded in 2016. On May 25, 2017, a seismic event was recorded near Alagir with a magnitude of about 3.0; on October 18, 2018, two events per day were recorded with epicenters at a distance of 58 and 36 km from Vladikavkaz; on December 8, 2018, between Alagir and Ardon (near the villages of Kadgaron, Ramonovo and Tsalikovo) a seismic event with a magnitude 3.3 occurred; on April 12, 2018, and April 26, 2018, seismic events occurred near the town of Alagir; on February 16, 2019, two events per day with magnitudes 3.5 and 3.7 occurred and on February 21, 2019, two events with M = 3.4 were registered. All these seismic events are united by the sublatitude zone of their confinement, which coincides with the spatial position of the Vladikavkaz fault, which is convincing evidence of the seismic activity of this territory at the present time primarily due to the activity of the Vladikavkaz fault. This fact proves the need to conduct continuous monitoring of the seismic situation and forehanded taking preventive measures.The article provides a detailed description of the Ardon and Vladikavkaz regional seismogenic deep faults using the data from the latest results of their research; the article also describes the engineering-geological and geomorphological conditions of the town territory based on a set of data on the physical and mechanical properties of soils and the results of engineering and geological and seismic zoning, that is provided with the attached schematic maps.
|Issue||2019, № 4 (Т. 11)|
|Key words||Seismic hazard, active tectonic deep faults, engineering and geological conditions, geological zoning, seismic microzonation, monitoring.|