Seismic hazard of Romania: Deterministic approach

The seismic hazard of Romania is estimated in terms of peak-ground motion v alues-displacement, velocity, design ground acceleration (DGA)--computing c omplete synthetic seismograms, which are considered to be representative of the different seismogenic and structural zones of the country. The determi nistic method addresses issues largely neglected in probabilistic hazard an alysis, e.g., how crustal properties affect attenuation, since the ground m otion parameters are not derived from overly simplified attenuation "functi ons," but rather from synthetic lime histories. The synthesis of the hazard is divided into two parts, one that of shallow-focus earthquakes, and the other, that of intermediate-focus events of the Vrancea region. The previous hazard maps of Romania completely ignore the seismic activity in the southeastern part of the country (due to the seismic source of Shabl a zone). For the Vrancea intermediate-depth earthquakes, which control the seismic hazard lever over most of the territory, the comparison of the nume rical results with the historically-based intensity map show significant di fferences. They could be due to possible structural or source properties no t captured by our modeling, or to differences in the distribution of damage able buildings over the territory (meaning that future earthquakes can be m ore spectacularly damaging in regions other than those regions experiencing damage in the past). Since the deterministic modeling is highly sensitive to the source and path effects, it can be used to improve the seismological parameters of the historical events.