SEISMICITY of the BAIKAL REGION and TRANSBAIKALIA in 2016–2017

Abstract

We consider a character of the seismic process in the Baikal region and Transbaikalia in 2016–2017. During the considered period, 17869 earthquakes with KR≥5.6 were registered; 95 % of these seismic events were localized in the Baikal rift zone. The largest earthquakes occurred at the north-eastern flank of the Baikal rift on November 22, 2016 (KR=13.9, Mw=5.0) and April 3, 2017 (KR=13.5, Mw=4.8). Felt effects, not exceeding 5, were observed for 47 regional earthquakes. Focal mechanisms were determined from P-wave first-motion polarities for 73 seismic events (KR≥9.4) and seismic moment tensors (scalar seismic moments, moment magnitudes, focal mechanisms) were calculated from surface wave amplitude spectra and regional P-wave first-motion polarities for 12 seismic events (KR≥11.9, Mw≥4.2). It was found that normal faults and combined types of motions were realized in sources of 94 % of the earthquakes with the obtained focal mechanisms. In general, moderate seismic activity was observed in 2016–2017.