Macroseismic intensity prediction equations for Vrancea intermediate-depth seismic source

This paper focuses on the development of a macroseismic intensity prediction equation (MIPE), for Vrancea intermediate-depth seismic source, that is able to differentiate between the sites located in the fore-arc and back-arc regions of the Carpathians Mountains. The database consists of more than 9000 observed data points (pairs of sites and macroseismic intensities) for six strong earthquakes originating from Vrancea intermediate-depth seismic source. Throughout this paper, the macroseismic intensities are expressed on MSK scale. The coefficients of the MIPE and the standard deviations of the model are obtained through the maximum likelihood method. The MIPE proposed for Vrancea intermediate-depth seismic source is valid for a magnitude range from M w 6.0 to M w 7.7 and for epicentral distances up to 1000 km in the fore-arc region and up to 800 km in the back-arc region. The inter- and intra-event residuals of the model are investigated, and magnitude and distance scaling are discussed. The predictive results obtained with the proposed MIPE are compared with other results from the literature. In the end, the correlation between the observed values of ground motion amplitudes and macroseismic intensities is discussed. In addition, an empirical relation between ground motion amplitudes and macroseismic intensities is obtained. Copyright Springer Science+Business Media Dordrecht 2015