Seismic Intensity Estimates for the Baikal–Olekma Section of the Baikal–Amur Railway

Abstract

In this study, we calculated the seismic intensity for the Baikal–Olekma section of the Baikal–Amur Railway based on data on seismicity on the northeastern flank of the Baikal Rift Zone in 1985–2021. During the analysis of earthquakes with an epicentral intensity higher than 4 (1484 events), we selected 270 earthquakes with Ms = 2.1–6.6, whose calculated intensity exceeded 4 points directly on the railway track from the total number of the recorded seismic events (more than 150 000 earthquakes with M ≥ 1.0). The highest intensity values (8–9) were obtained for large earthquakes close to the Baikal–Olekma section of the Baikal–Amur Railway (Δ < 10 km, Ms = 6.1–6.2). A recurrence interval of such seismic events along the considered section of the railway is 20–60 years. The data are agree well with the macroseismic data available, which confirms the correctness of the results. At the same time, macroseismic effects from strong (Ms ≥ 6.6) but remote earthquakes (Δ = 360–1000 km) were found to have no significant impact on the Baikal–Olekma section of the Baikal–Amur Railway. The calculated values of intensity and recurrence intervals of earthquakes should be taken into account when designing, constructing, and operating industrial and civil infrastructure within the study area.