Earthquake rates inferred from active faults and geodynamics: the case of the External Dinarides

Abstract

The goal of earthquake rate models is to define the long-term rate of seismicity above an established magnitude threshold. No earthquake rate models exist for the External Dinarides, although this area is prone to frequent earthquakes that have significant impacts on natural and human environments. In this study, we apply a tectonic/geodynamic approach to build a fault-based and a deformation-based earthquake rate model for the External Dinarides. The main difference between the two models is the inclusion of off-fault seismicity in the deformation-based earthquake rate model. We explore the impact of the moment-balancing uncertainties on the expected number of earthquakes above an established magnitude. The results show comparable earthquake rates for both input models. The slip rate, the elastic modulus and the seismogenic depth play important roles in the variability of earthquake rates, whereas the effects of the corner magnitude and the Gutenberg-Richter β parameter are insignificant. A comparison with the available historical seismic catalogue shows good agreement for MW>5.8 earthquakes