Regional modification of acceleration attenuation functions

abstract Strong ground motion attenuation functions developed on the basis of data from one physiographic region do not generally apply to other regions due to both differences in source characteristics and seismic wave attenuation. At the same time, many regions with known seismic hazard lack sufficient strong motion data to develop regionally unique attenuation functions. A method is proposed for the estimation of peak ground acceleration attenuation functions for these regions. The technique makes use of regional variations in relationships between event magnitude and epicentral intensity and event magnitude and radius of the felt area to correlate peak ground accelerations from a region which has empirical strong motion data to one lacking this data. The necessary relationships to make the modifications require only limited instrumental observations. The method is an improvement over previously suggested schemes in that the fundamental assumptions are more restricted than those previously used.