The first step in estimation of seismic losses in urban areas is the
assessment of regional seismic hazard. The source and local site parameters
determine the accuracy of the hazard model. Using locally derived input
parameters in site response modeling and hazard analyses, the earthquake
potential of Zeytinburnu region in Istanbul is investigated in detail. In this study, two alternative source models including
area and fault (line) sources are considered in the hazard computations. Analyses
are initially performed using generic rock and soil conditions considering
return periods of 475, 975 and 2475 years. Then, site-specific seismic hazard
analyses are made using available local soil conditions. Probabilistic seismic
hazard analyses with line sources and local soil models yield significantly
different results than area sources and a generic soil model for all return
periods. This observation points out the fact that detailed local source and
site parameters should be employed in hazard analyses. In summary, numerical
results obtained with locally derived input parameters indicate that Istanbul
has significant potential for hazard in terms of both local earthquake
occurrence and site amplifications