Abstract
The Vrancea seismoactive region, characterized by intermediate-depth earthquakes, is the quake source that has to be taken into account for microzonation purposes of Bucharest that could suffer serious damage also because of the severe local site effects. The strong seismic events originating in Vrancea have caused the most destructive damage experienced on the Romanian territory and may seriously affect vulnerable high risk constructions (such as nuclear power plants, chemical plants, large dams, pipelines etc.) located on a wide area, from Central Europe to Moscow.
Realistic numerical simulation, describing the propagation of the seismic wavefield generated by a given quake in a complex geological structure, is a powerful tool, that may be efficiently used to estimate the ground motion for microzonation of the whole Bucharest area.
The realistic modelling of ground motion is carried out by means of a sophisticated hybrid technique that combines modal summation (Panza, 1985; Vaccari et al, 1989; Florsch et al., 1991; Panza, 1993; Romanelli et al., 1996) and finite difference (Fäh 1991; Fäh and Panza, 1994; Fäh et al., 1994). The input data necessary for computations are the laterally variable anelastic structural model and the focal mechanism of the seismic source.
The medium is modelled with a regional layered structure (bedrock structure), containing the seismic source and assumed to be representative of the path from the source to Bucharest, and a local structure, that is a NE20°SW oriented cross section, describing the local structure of Bucharest, along the studied path. The seismic source is described by a double-couple, buried in a layered medium, and corresponds to the focal mechanism of the May 30, 1990 Vrancea earthquake. The upper frequency limit considered in the computations is 1.0 Hz, and this allows us the modelling of seismic input appropriate for ten storeys and higher buildings.
The simulated signals are satisfactorily compared with the available instrumental records from Magurele station (44.347°N, 26.030°E), and stability tests are performed with respect to the variation of focal mechanism, regional and local structure.
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References
Alterman, Z.S., Karal, F.C. (1968), Propagation of elastic waves in layered media by finite difference methods, Bull. Seism. Soc. Am., 58, 367–398.
Boore, D.M. (1972), Finite difference methods for seismic wave propagation in heterogeneous matherials, Methods in Computational Physics, Vol. 11, B.A. Bold, ed., New York, Academic Press, 1–37.
Dziewonski, A.M., Ekstrom, G., Woodhouse, J.H., Zwart, G. (1991), Centroid-moment tensor solutions for April-June 1990; Physics of the Earth and Planetary Interiors, 66, 133–143.
Enescu, D., (1980), Contribution to the knowledge of the focal mechanism of the Vrancea strong earthquake of March 4, 1977, Rev. Roum. Géol, Géophys., Géogr., Ser. Géophys., 24, 3–18.
Enescu, D., Zugrãvescu, D. (1990), Geodynamic consideration regarding the eastern Carpathians are bend, base on studies on Vrancea earthquakes, Rev.Roum.Géophysique, 34, 17–34.
Enescu, D., Enescu, B.D. (1993), Contributions to the knowledge of the genesis of the Vrancea (Romania) earthquakes, Romanian Reports in Physics, 45, 777–796.
Fäh, D. (1991), Stima del moto sismico del suolo in bacini sedimentari, Tesi di dottorato, tutor: G.F. Panza, Trieste University.
Fäh, D., Panza, G.F. (1994), Realistic modelling of observed seismic motion in complex sedimentary basins, Annali di Geofisica, Vol.XXXVII, No. 6, 1771–1796.
Fäh, D., Suhadolc, P., Müller, St., Panza, G.F. (1994), A hybrid method for the estimation of the ground motion in sedimentary basins: quantitative modelling for Mexico city, Bull. Seismol. Soc. Am., 84, No.2, 383–399.
Florsch, N., Fäh, D., Suhadolc, P., Panza, G.F. (1991), Complete synthetic seismograms for high-frequency multimode SH-waves, PAGEOPH, 136, 529–560.
Fuchs, K., Bonjer, K.P., Bock, G., Radu, C., Enescu, D., Jianu, D., Nourescu, A., Merkler, G., Moldoveanu, T., Tudorache, G. (1978), The Romanian earthquake of March 4, 1977. II. Aftershocks and migration of seismic activity, Tectonophysics, 53, 225–247.
Ismail-Zadeh, A.T., Panza, G.F., Naimark, B.M. (1996), Stress in the descending relict slab beneath Vrancea, Romania, ICTP preprint, IC/96/93, Trieste, Italy.
Kelly, K.R., Ward, R.W., Treitel, S., Alford, R.M. (1976), Synthetic seismograms: A finite difference approach, Geophysics, 41, 2–27.
Mândrescu, N, Radulian, M. (1998), Seismic microzoning of Bucharest (Romania): a critical review; Natural Hazards, this issue.
McKenzie, D.P. (1970), Plate tectonics of Mediterranean region, Nature, 226, 239–242.
McKenzie, D.P. (1972), Active tectonics of the Mediterranean region; Geophys., J.R.A.S., 39, 109–185.
Oncescu, M.C. (1984), Deep structure of the Vrancea region, Romania, inferred from the simultaneous inversion for hypocenters and 3-D velocity structure, Ann.Geophys., 2, 23–28.
Oncescu, M.C., Burlacu, V., Anghel, M., Smalberger, V. (1984), Three dimensional P-wave velocity image under the Carpathian Are, Tectonophysics, 106, 305–319.
Oncescu, M.C, Trifu, C-I. (1987), Depth variation of moment tensor principal axes in Vrancea (Romania) seismic region, Ann.Geophysicaes, Ser.B, 5, 149–154.
Oncescu, M.C, Trifu, C.-I. (1987), Depth variation of the seismic moment tensor principal axes in Vrancea (Romania) seismic region, Ann.Geophysicae, 5B, 149–154.
Oncescu, M.C, Mârza, V.l., Rizescu, M., Popa, M. (1998), The Romanian earthquake catalogue between 984–1996, Natural Hazards, this issue.
Panza, G.F. (1985), Synthetic seismograms: the Rayleigh waves modal summation, J.Geophys., 58, 125–145.
Panza, G.F., Suhadolc, P. (1987), Complete strong motion synthetics, Seismic Strong Motion Synthetics, Academic Press Inc., London, 153–204.
Panza, G.F. (1993), Synthetic seismograms for multimode summation—theory and computational aspects, Acta Geod. Geoph. Mont. Hyng., Vol. 28 (1-2), 197–247.
Radulian, M., Mândrescu, N., Popescu, E., Utale, A., Panza, G.F. (1998), Seismic activity, stress field and seismogenic zones in Romania, Terra Nova, in press.
Radulian, M., Ardeleanu, L., Campus, P., Šilený, J., Panza, G.F. (1986), Waveform inversion of weak Vrancea (Romania) earthquakes, Studia Geoph. et Geod., 40, 367–380.
Romanelli, F., Bing, Z., Vaccari, F., Panza, G.F., (1996), Analytical computations of reflection and transmission coupling coefficients for Love waves, Geophys. J. Int., 125, 132–138.
Vaccari, F., Gregersen, S., Furlan, M., Panza, G.F. (1989), Synthetics seismograms in laterally heterogeneous, anelastic media by modal summation of the P-SV waves, Geophys. J. Int., 99, 285–295.
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Moldoveanu, C.L., Panza, G.F. (1999). Modelling, for Microzonation Purposes, of the Seismic Ground Motion in Bucharest, Due to the Vrancea Earthquake of May 30, 1990. In: Wenzel, F., Lungu, D., Novak, O. (eds) Vrancea Earthquakes: Tectonics, Hazard and Risk Mitigation. Advances in Natural and Technological Hazards Research, vol 11. Springer, Dordrecht. https://doi.org/10.1007/978-94-011-4748-4_9
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