Magneto-based earthquake hazard models for Absheron Peninsula

An earthquake hazard model based on the variations of magnetic susceptibility of rocks integrating with macroseismic parameters of a credible earthquake, considering dynamics of the site effects was developed and applied to the Absheron peninsula (Azerbaijan).Magnetic well logging data, lithological and geological maps of the Absheron peninsula, seismic catalogues were also utilized.The maximum expected ground motion for Absheron is estimated for shallow Baku-Caspian 25.11.2000earthquake near the site, which is noted as a scenario "near-event earthquake" and considered as credible earthquake with moment magnitudes Mw=6.18 and Mw=6.08.The moment magnitude is accepted as Mw=6.8.Local site effect assessment was carried out by detailed geotechnical investigation of soil from bedrock to surface using one-dimensional (1-D) ground response analysis with SHAKE2000.We estimated the response of soil layers under earthquake effect by computing soil amplification and the variation of ground motion characteristics on the surface.Based on the scenario earthquake parameters, the surface peak ground acceleration is computed, correlated with the MSK-64 intensity, and mapped.We simulated ground acceleration, seismic intensity and magnetic susceptibility.The northeast and southeast parts of the peninsula are characterized by surface peak ground acceleration of 165-250 gal and intensity VIII-IX, which is 31% and 49% higher than the seismic hazard in the same values compared to other parts.For the eastern part, magnetic susceptibility varies between 0.5-1.0.The values indicate the distinct relationship of variations in the magnetic field with the seismic effect of earthquakes.Our approach makes a significant contribution to improving existing methods for seismic hazard assessment.