Abstract.A seismic hazard map proposed as part of a new building code for Romania is presented here on basis of the recommendations in EUROCODE 8.Seismic source zones within an area of about 200 km around Romania were constructed considering seismicity, neotectonics and geological development. The probabilistic seismic hazard assessment in terms of intensities is performed following Cornell (1968) with the program EQRISK (see Mc Guire, 1976), modified by us for use of intensities.To cope with the irregular isoseismals of the Vrancea intermediate depth earthquakes a factor is introduced to the attenuation law (Kövesligethy, 1907). Using detailed macroseismic maps of three earthquakes is calculated by fitting the attenuation law to observed intensities, i.e. to local ground conditions. Strong local variation of is avoided by a gridding of 0.5 • in longitude and 0.25 • in latitude. The contribution of the Vrancea intermediate depth zone to the seismic hazard at each grid point is computed with the corresponding representative . A seismogenic depth of 120 km is assumed.The final seismic hazard is the combination of both contributions, of zones with crustal earthquakes and of the Vrancea intermediate depth earthquakes zone. Calculations are done for a recurrence period of 95, 475 and 10 000 years. All maps show the dominating effects of the intermediate depth earthquakes in the Vrancea zone, also for the capital Bucharest.

The moderate-size earthquake (ML 5.7) which occurred on November 22, 2014 in Vrancea region (Romania), is the largest crustal event instrumentally recorded. Its aftershock sequence lasted around 70 days, 222 earthquakes with M L ≥ 0.1 being located using the records collected by the Romanian seismic network. The seismic sequence occurred mainly in the lower crust (depths greater than 25 km), and the epicenter distribution-along a NNE-SSW direction-follows the orientation of the Vrancea crustal earthquakes alignment. The spatio-temporal distribution of the seismic activity, as well as the seismic energy release during the seismic sequence are analysed in detail, and the focal mechanisms of the largest events-34 shocks with local magnitude ≥ 1.8-are determined using reliable P-wave polarities and amplitude ratios. Taking into consideration that the moderate-size shock on November 22, 2014 is the strongest instrumentally recorded crustal earthquake in the region, its focal mechanism provides highly relevant seismological information on the deformation field in front of the Carpathian bend. The obtained fault plane solution indicates normal faulting with a dominant dip-slip component; both nodal planes being oriented NW-SE.

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Abstract. Since 2007 Bulgaria and Romania are members of the European Union. All member states have to introduce the European earthquake building code EUROCODE 8 (EC 8) in the coming years. Therefore, new seismic hazard maps have to be calculated according to the recommendations in EC 8.Here the authors present a novel approach to compute such hazard maps. We prefer to use the macroseismic intensity as hazard parameter because of two reasons:-The irregular azimuthal attenuation pattern of the Vrancea intermediate depth earthquakes can be advantageously taken into account by using detailed macroseismic maps.-The intensity is directly related to the degree of damage and is the original information in the historical earthquake catalogues.The main base of our probabilistic analysis is the earthquake catalogue for SE-Europe (Shebalin et al., 1998) in combination with national and regional catalogues. Fore-and aftershocks were removed. Seismic source zones inside an area of about 200 km around Romania and Bulgaria were defined based on seismicity, neotectonics and geological development. For each seismic source the intensity-frequency relation was calculated and a maximum possible earthquake as well as a seismogenic depth was estimated. An appropriate attenuation law was assumed. To cope with the irregular isoseismals of the Vrancea intermediate depth earthquakes, a factor was included in the macroseismic attenuation law. Using detailed macroseismic maps of three strong intermediate depth earthquakes, was calculated for each observation. Strong local variations of are avoided by averaging The contributions of all seismic sources, the crustal normal depth source zones and the Vrancea intermediate depth zone, were summed up and the annual probability of exceedance was calculated. The contribution of the Vrancea intermediate depth zone to each grid point was computed with the corresponding representative of this point; a seismogenic depth of 120 km has been assumed.Each final seismic hazard map is a combination of two maps, the one for normal depth source zones and the one for the Vrancea intermediate depth zone. This is illustrated for a recurrence period of 475 years. Additional hazard maps were calculated for different recurrence periods.

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