Stochastic Simulation and Development of the Ground Motion Prediction Equation for the Baikal Rift Zone

Abstract

To obtain realistic and correct estimates of seismic effects in the Baikal Rift Zone (BRZ), a ground motion prediction equation has been developed based on the records of local earthquakes (magnitudes mb ~ 3.4–5.5, hypocentral distances R ~ 15–220 km) obtained by Ulan-Ude and Severomuisk seismic stations. At the first step, in our previous works, using stochastic simulation of the accelerograms of the recorded local earthquakes we estimated the regional parameters of radiation and propagation of seismic waves (stress drop in an earthquake source, quality function of the medium, geometrical spreading, wave attenuation at high frequencies, local site amplification, etc. These parameters were then used to generate a set of earthquake accelerograms over a wide range of magnitudes (Mw ~ 4.0–8.0) and distances (R ~ 1–200 km) on a rock site, and a ground motion prediction equation (GMPE) describing the dependence of peak ground accelerations (PGA) and peak ground velocities (PGV) on magnitude and distance are constructed. The obtained PGA estimates are compared with those estimated from GMPE recommended for BRZ by the international Global Earthquake Model (GEM) project. The scatter of the estimates obtained based on GEM GMPE indicates the relevance of developing the own GMPEs for Russian regions based on the records of local earthquakes. The GMPE derived in this work can be used for seismic hazard assessment in the BRZ eastern part and will be updated as new data are acquired.