ISSN 1069-3513, Izvestiya, Physics of the Solid Earth, 2008, Vol. 44, No. 9, pp. 691–705. © Pleiades Publishing, Ltd., 2008. Original Russian Text © V.I. Ulomov, K.N. Akatova, N.S. Medvedeva, 2008, published in Fizika Zemli, 2008, No. 9, pp. 3–19. Estimation of Seismic Hazard in the Kaliningrad Region V. I. Ulomov, K. N. Akatova, and N. S. Medvedeva Schmidt Institute of Physics of the Earth (IPE), Russian Academy of Sciences (RAS), Bol’shaya Gruzinskaya ul. 10, Moscow, 123995 Russia e-mail:
[email protected] Received December 17, 2007 Abstract—The paper discusses problems of seismic zoning of the Kaliningrad region, where a series of per- ceptible earthquakes occurred in 2004; the strongest event had a magnitude of Ms = 4.3 and produced shakings of an intensity of 6 in the coastal zone of the Sambiiskii Peninsula, classified as a 5-intensity zone. The enhanced seismic effect is shown to be caused by bad ground conditions, long-term action of seismic effects, resonance phenomena, and other factors. To gain additional constraints on the seismic hazard degree in the Kaliningrad region, the paper discusses an improved version of the model of earthquake sources underlying the compilation of normative maps of seismic zoning (OSR-97). Modified fragments of OSR-97 probability maps of the Kaliningrad region are constructed at different levels of probability that the seismic effect indicated in the maps will be exceeded over 50 yr. It is shown that additional seismological investigations should be con- ducted in this region. PACS numbers: 91.30.Px DOI: 10.1134/S1069351308090012 1.