Earthquake on march 8, 2020 within the Kotlas graben (Central Russian aulacogen)

The results of the instrumental processing of the seismic event on March 8, 2020 in the Lensky district of the Arkhangelsk region, near the border with the Komi Republic, in the middle reaches of the Vychegda river are presented. Particular attention is paid to determining the nature of the seismic event. It is classified by us as a «tectonic earthquake» and has the following parameters: 62.578N, 49.122E, t0 = 23:29:39.4 (UTC), h = 30 km, Kp = 8.9, ML = 2.8, Ms = 2.0, еrror ellipse: Az Major = 40°, Rminor = 6.0 km, Rmajor = 17.8 km. There are no macroseismic earthquake data since the epicentral region is located within the Yarensky State Biological Reserve and is poorly populated. In tectonic terms, the March 8 earthquake refers to the Kotlas graben, which stands out as an independent structure and is the northeastern end of the Central Russian aulacogen, marking the collision suture zone between Fennoscandia and Volga-Sarmatia. The occurrence of seismic events within Riphean aulacogens confirms that they are seismic generating structures.