ACTIVE FAULTS IN ROMANIA: SEISMOTECTONIC AND SEISMOLOGICAL ANALYSIS. IMPLICATIONS FOR SEISMIC HAZARD AND RISK MANAGEMENT

This study presents an integrated seismotectonic synthesis of the active fault systems of Romania and adjacent areas of the western Black Sea, based on the combined interpretation of geological, geophysical, and seismological data. An updated inventory of active crustal and transcrustal faults is compiled and systematically characterized in terms of geometry, kinematics, depth extent, and seismic potential. The results highlight the dominant role of tectonic inheritance, showing that present-day deformation is primarily accommodated through the reactivation of pre-existing lithospheric discontinuities formed during earlier Alpine and pre-Alpine tectonic stages. Active deformation is organized into several major tectonic domains—the Carpathian orogen, the intra-Carpathian (Pannonian) region, the Carpathian foreland and platform areas, and the Dobrogea–western Black Sea domain—each displaying distinct structural styles and seismic behavior. Although the Vrancea intermediate-depth source remains responsible for the largest earthquakes in Romania, distributed moderate-magnitude crustal seismicity associated with active faults represents an important and often underestimated component of regional seismic hazard. The study emphasizes the coupling between deep lithospheric processes, regional plate-scale forces, and shallow crustal deformation, and demonstrates the importance of incorporating fault-based seismotectonic information into seismic hazard assessment. The resulting active-fault database provides a consistent framework for seismic source modeling, probabilistic hazard analysis, and risk-reduction strategies at national and regional scales.