Refinement of seismic regime parameters for the Lena River delta region

Remote Arctic seismically active areas, including the Lena Delta region, need more precise seismic-regime characterization and hazard zoning. Modern seismological data made it possible to identify two main seismolineaments in the Lena Delta and to determine for each: recurrence-plot parameters, seismogenic layer depth in the crust, maximum magnitude, principal stress-axis orientation, and generalized focal-mechanism parameters. Applying a Bayesian approach yielded robust estimates of the maximum magnitude despite the limited number of strong events. We built a one-dimensional crustal velocity model using the receiver-function method, which revealed zones of probable lithological boundaries. A comparative analysis with the corresponding seismolineaments from the Russian general seismic hazard zoning models highlighted the need to adjust existing models for better accounting of local features. The identified seismolineaments show distinct differences in recurrence rates and maximum magnitudes, indicating varied tectonic regimes within the study area. The results can be used for detailed seismic zoning of the Lena Delta and provide a foundation for improving seismic risk assessments and informing infrastructure planning in the Arctic.