SEISMIC HAZARD IN THE PANNONIAN REGION László Tóth 1,3 , Erzsébet Gy ri 2 , Péter Mónus 1,3 , Tibor Zsíros 1,3 1: Seismological Observatory, Hungarian Academy of Sciences, Budapest, Hungary toth@georisk.hu 2: Research Group of Geophysics and Environmental Physics of HAS , Budapest, Hungary 3: GeoRisk Earthquake Research Institute, Budapest, Hungary ABSTRACT Seismic hazard for single sites and hazard maps for the whole Pannonian region (44.0-50.0N; 13.0-28.0E) have been calculated. The hazard assessment was carried out using a probabilistic approach by incorporating a wide range of parameter values and viable interpretations that were consistent with the data. Alternative interpretations were described by branches of a logic tree. Each branch was weighted according to the ability of that interpretation to explain the available data. The resulting seismic hazard map describes expected shaking with a 475-year return period in terms of peak ground acceleration. Furthermore, some important contributors to seismic risk are highlighted, and a liquefaction hazard map is presented for the territory of Hungary. Keywords: seismicity, seismic hazard, Pannonian Basin INTRODUCTION The Pannonian region is situated between the Mediterranean area, which is one of the most seismically active regions in the world, and the East European platform, which can be treated as nearly aseismic. Deformation in the Pannonian basin system is ongoing (Bada et al. 1998, Horváth and Cloetingh 1996). One of the most direct pieces of evidence for the continuing deformation, in addition to GPS geodetic data (Grenerczy et al. 2002), is current seismic activity (Bada et al. 1999, Gerner et al. 1999). In the following paper, we give a brief review of seismic hazard methodology, present the latest seismic hazard map of the region and highlight some chief factors (e.g., site effect, liquefaction) contributing to seismic risk. 369 © 2006 Springer. Printed in the Netherlands. N. Pinter (eds.), The Adria Microplate: GPS Geodesy, Tectonics and Hazards, 369–384.