THE 29.07.2022 ML = 6.2 TSAGAN-SHIBETU EARTHQUAKE AND SPATIAL POSITION OF THE FOCAL AREA IN THE WESTERN MOUNTAIN FRAMING OF THE TUVA BASIN
A.F. Emanov1, A.A. Emanov1,2, E.V. Shevkunova1, E.A. Gladyshev1
1Altay-Sayan Branch of Geophysical Survey, Siberian Branch of the Russian Academy of Sciences, Novosibirsk, Russia
2Trofimuk Institute of Petroleum Geology and Geophysics, Siberian Branch of the Russian Academy of Sciences, Novosibirsk, Russia
Keywords: Eastern Altai, Tsagan-Shibetu Range, Tsagan-Shibetu earthquake, aftershocks and foreshocks
Abstract
The 29.07.2022 (UTC time 13:01:10.1) Tsagan-Shibetu earthquake with ML = 6.2, MW = 5.5 occurred in the eponymous mountain range in the eastern Altai Mountains (Gorny Altai), in proximity to the Tuva Basin (50.51º N, 90.69º E). The Tsagan-Shibetu Range was seismically inactive in the twentieth century, while neighboring with seismically active ones: the focal area of the 1970 Ureg-Nur earthquake with MS = 7.0 and the seismically active Shapshal Range where earthquakes with magnitude of up to five occurred quite frequently, however, no large earthquakes have hitherto been reported. Significant alterations in the structure of seismicity of Gorny Altai occurred after the 2003 Chuya earthquake with MS = 7.3: the period of quiescence was followed by emergence of new zones of enhanced seismic activity, with the Tsagan-Shibetu Range representing one of them. The internal structure of the mountain range is characterized by the formation of a triple-planed focal area with the pulse-like seismic process developing over time. The evolution of high seismicity in the considered mountain range occurred in the presence of foreshocks.
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