First International Conference on MOLDAVIAN RISKS – FROM ...

<strong>First</strong> <strong>International</strong> <strong>Conference</strong> on MOLDAVIAN RISKS - FROM GLOBAL TO LOCAL SCALE
16-19 May 2012, Bacau, Romania
SEISMOGENIC ZONES AND SEISMIC HAZARD AT LOCAL
AND REGIONAL SCALES IN MOLDAVIA
Mircea Radulian, Neculai Mandrescu
National Institute for Earth Physics, Magurele, Ilfov, Department of Seismology
Corresponding author: Mircea Radulian, mircea@infp.ro
Abstract: The paper is presenting an overall characterization of the seismotectonics and
seismicity in the Moldavia region as fundamentals to define the seismogenic zones and the
associated seismic hazard for this region. The hazard level is clearly controlled by the
earthquake activity in the Vrancea region. Some effects recorded at the southern boundary
of the Moldavian Platform (Galati – Braila) are induced by the shallow seismicity located
along the system of NW-SE oriented faults (Peceneaga-Camena, Sfantu Gheorghe,
Trotus), crossing the northern Dobrogea and terminating in the Barlad Depression. The
distribution of the seismic hazard due to the Vrancea earthquakes is analyzed in connection
with the revised macroseismic data and instrumentally recorded accelerograms. The effects
of the focal depth, source directivity and seismic wave attenuation and their impact on
hazard level are investigated. The amplification of the ground motion due to the shallow
geological layers and resonance frequency in the Bacau area and surroundings are
estimated on the basis of borehole data. Implications on management strategy to mitigate
earthquake risk are finally discussed.
Key words: seismogenic zone, Vrancea earthquake, seismic hazard, microzonation, Moldavia,
Bacau
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