Towards a seismogenic source model of the Dinarides

Abstract

Geology-based seismogenic source models are becoming the fundamental input for seismic hazard assessment at the scale of an entire country. In this work, we will illustrate in simple steps the complex process that leads from basic data to a fully-fledged seismogenic source model of the Dinaride thrust belt, running along coastal Croatia, Montenegro and part of Albania. We started from a layer of basic geological and structural data and explored a wide range of indicators of recent tectonic activity, such as drainage anomalies/diversions and displaced or warped geological markers. We then analyzed the interplay of these indicators with known or prospective tectonic structures. To the picture thus obtained, we added a layer with a revised historical seismic catalog and selected a few earthquakes for which we re-estimate epicenter and magnitude. At the end of our analyses we combined all these data in a structured GIS database. With these data at hand, we also compared the longer-term indicators with present-day stress/strain data such as GPS velocities and earthquake focal solutions. Following the approach already developed for the construction of the Database of Individual Seismogenic Sources for Italy, we developed a seismogenic source model for the Dinarides in which the better constrained seismogenic faults have been mapped and parameterized and made ready for use in seismic hazard practice. We believe that our experience in the Dinarides will become useful in unifying and formalizing the process of constructing seismic source models in other countries.