Generic approach for modelling earthquake hazard

The earthquake attenuation behaviour is a critical part of seismic hazard modelling for regions of low and moderate seismicity. This paper presents a new approach for attenuation modelling, which does not involve the use of strong motion data, and is based on taking measurements of the shear wave velocity (SWV) in bedrock by a non-invasive technique to characterize the transmission of seismic waves. The developed filters are then applied to the generic source model for intraplate earthquakes for calculating the frequency content of seismic waves at the bedrock surface and was used as input to soil response analyses for the determination of site seismic hazard. Ground motion parameters and response spectra are then obtained from the stochastically simulated accelerograms to develop representative attenuation models for rock conditions. The described approach of obtaining a seismic attenuation relationship based on modelling the rock and soil crustal properties is not constrained to any particular environment. Thus, the approach is described as generic. The northern suburbs of the city of Melbourne, Australia, have been used as the study area to illustrate the modelling procedure. The peak ground velocity values (PGV's) predicted from attenuation relationship developed from this study are well correlated with the PGV's inferred from MMI Intensity data of historical earthquakes felt in Melbourne over the past hundred years.