Macroseismic intensity attenuation in western China

Abstract

Macroseismic intensity data play an important role in seismic hazard analysis and in developing reliable earthquake loss models. This paper adopts an ellipse model to predict the macroseismic intensity attenuation in both the long-axis and the short-axis directions based on 136 earthquakes recorded throughout western China during 1970–2012. The geometric spreading and energy release of seismic waves are considered in the models proposed in this study. The proposed relation describes the macroseismic intensity simply as a function of the surface wave magnitude, source-to-site distance, and focal depth. This study adopts the focal depth that is not often considered in the current intensity prediction equations in China and uses different functional forms in the long- and short-axis directions. Based on residual analysis and evaluation, a more suitable macroseismic intensity predictive equation was established for western China, and it was compared and discussed with macroseismic intensity prediction equations of other researchers.