Empirical ground motion equations for the Eastern Alps, Austria

Abstract

We present a new set of region-specific empirical Ground Motion Equations for the transition zone between the southern Vienna Basin and the Eastern Alps, the area with the highest seismic hazard in Austria. The equations include Intensity Prediction Equations for EMS-98 macroseismic intensity, Ground Motion Prediction Equations for four instrumental ground motion variables, and Ground Motion Intensity Conversion Equations to convert instrumental to macroseismic ground motion parameters. The equations are calibrated from seven low-to-moderate-magnitude earthquakes \(\left(3.0\le {M}_{w}\le 4.1\right)\) between 2021 and 2024. These events were recorded by a significantly densified seismic network and resulted in the most extensive macroseismic dataset for the region to date, with about 2,000 intensity data points and high-quality waveforms from both permanent and temporary stations. Our equations capture local attenuation characteristics and near-field effects not resolved by existing national models. These GMEs represent an important step towards improving regional seismic hazard assessment and rapid impact estimation for moderate-magnitude earthquakes in this low-to-moderate seismicity area.