Abstract—

This paper considers the September 28, 2019 earthquake that occurred on the northeastern flank of the Baikal Rift Zone (BRZ), called the Lenger earthquake after its location. The seismic moment tensor and hypocentral depth of the event are calculated from data on surface wave amplitude spectra with additional information on P-wave first-arrival polarities recorded at regional stations. The hypocentral depth is 11–12 km, the moment magnitude M_w = 5.1, and the scalar seismic moment M₀ = 5 × 10¹⁶ N m. The earthquake source is formed under the influence of horizontal submeridional extension and subhorizontal NE–SW compression. The latter approximately coincides with the azimuth of the fast S-wave velocity in the upper mantle obtained from SKS-splitting and surface wave tomography data. The Lenger earthquake was felt at epicentral distances of more than 600 km. Comparison of its macroseismic effects with effects of other strong seismic events in the study area demonstrates that the regional macroseismic field equation should be actualized for the territory of the northeastern flank of the BRZ. Analysis of the obtained data, along with the available information on the stress-strain field of the crust of this area indicates that the geodynamical pattern of the conjunction zone of the northeastern flank of the BRZ and the Olekma–Stanovoi orogenic system influences the low-active Transbaikalia block. However, due to low tectonic activity, the tectonic stress accumulation period sufficient for the occurrence of relatively strong seismic events is larger than in regions with high-level tectonic activity.

中文翻译：

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2019年9月28日的地质，地球物理和宏观地震数据，M w = 5.1贝加尔湖裂谷东北部发生的地震

摘要-

本文考虑了2019年9月28日发生在贝加尔湖纵裂带（BRZ）东北侧面的地震，其所在地称为伦格地震。根据表面波振幅谱的数据以及在区域台站记录的P波初到极性的其他信息，计算出该事件的地震矩张量和震中深度。震源深度为11–12 km，矩震级M _w  = 5.1，标量地震矩M ₀  = 5×10 ¹⁶ N m。地震源是在水平的半地下伸展和水平的NE-SW压缩作用下形成的。后者与快S的方位角大致重合SKS获得的上地幔的波速分裂和表面波层析成像数据。在震中距离超过600 km时感到了Lenger地震。将其宏观地震效应与研究区域其他强地震事件的影响进行比较，结果表明，应该为BRZ东北侧领土实施区域宏观地震场方程。对所获得数据的分析以及该地区地壳应力-应变场的可用信息表明，BRZ东北侧面与Olekma-Stanovoi造山系统交汇区的地球动力学模式影响了低空活跃的Transbaikalia街区。但是，由于构造活动低，