The Muyakan Earthquake Sequence in the North Muya Region of the Baikal Rift Zone: Detailed Analysis and Possible Reasons

• Published in: Pure and applied geophysics 2022-09, Vol.179 (9), p.3157-3175
• Main Authors: Melnikova, Valentina I., Filippova, Alena I., Gileva, Nadezhda A.
• Format: Article
• Language: English
• Subjects: Earth and Environmental Science; Earth Sciences; Earthquakes; Fault lines; Flooding; Geological faults; Geophysics/Geodesy; Massifs; Mathematical analysis; Mountains; P waves; Railway stations; Rift zones; Seismic activity; Seismological data; Seismology; Sequencing; Surface water waves; Surface waves; Tectonics; Tensors; Thermal water; Tunnels; Wave data
• ISSN: 0033-4553; 1420-9136
• DOI: 10.1007/s00024-022-03124-7

We present results of detailed studies of the Muyakan earthquake sequence, which occurred in the North Muya region of the Baikal rift zone and which is the largest one in the Baikal region as a whole. In its epicentral area, more than 16 thousands of seismic events with M ≥ 1.0 were registered in 2014–2018. The considered sequence is of interest due to the specific tectonic pattern of the North Muya region, occupying a part of the mountain range between the Upper Angara and Muya rift basins, and the proximity of its epicentral field to the eastern portal of the North Muya tunnel of the Baikal-Amur Railway. An analysis of unique seismological data, obtained during the sequence, shows that its seismic regime is characterized by a division of the epicentral field into separate clusters, in which the earthquakes with the most reliably determined depths (about 600 seismic events) occurred in the upper crust (h 4–10 km, δh