The Tuva earthquakes of December 27, 2011, M L = 6.7, and February 26, 2012, M L = 6.8, and their aftershocks

Environmental effects of the 2011--2012 Tuva earthquakes (Russia): Application of ESI 2007 macroseismic scale in the Siberian mountains

“…In 1960-1980 there were repeated earthquakes with moderate magnitudes ( = 4 − 5.5), however the epicentral area of earthquakes 2011-2012 was practically aseismic more than 50 years [Emanov et al, 2014]. However the possibility of the strong earthquakes within Academician Obruchev ridge was determined with use of the seismogeological approaches.…”

“…The depth of hypocenter of the first earthquake was estimated as ℎ = 17 km, the second one ℎ = 14 km [Emanov et al, 2014]. The intensities of both shocks in the town Saryg-Sep, the nearest populated area, situated in 40 km from epicenter, were VII-VIII and VII on the MSK-64 scale, respectively.…”

“…The Tuva earthquakes were governed by same regularities. According to focal mechanisms (GS RAS, http://www.ceme.gsras.ru, [Emanov et al, 2014]), the motion of the first earthquake had mainly strike-slip kinematics; the second earthquake was characterized by predominated reverse fault kinematics with strike-slip components ( Figure 1). The dextral horizontal strike-slip is typical for north-western plane; the left-lateral slip are characterized by the north-eastern plane.…”

“…The white dashed lines show the supposed active faults, the continuous lines show the studied faults according to [Arzhannikov, 2000;Arzhannikov, Zelenkov, 1995]. The stars show the epicenters of Tuva earthquakes according to [Emanov et al, 2014]. The source mechanisms are based on GS RAS.…”