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Strong motion records and synthetic isoseismals of the Pyrgos, Peloponnisos, Southern Greece, Earthquake Sequence of March 26, 1993

Abstract

In this work, several seismological observations are presented in order to explain characteristic features of the earthquake sequence which occurred in March 1993 in southwestern Greece, very close to the city of Pyrgos.

Fault plane solutions of the largest fore- and aftershocks and the main shock, as well as the directions at which the maximum ground accelerations were recorded suggest that this earthquake sequence has been developed by rupturing three distinct focal planes with different focal mechanisms. The first focal plane, located in the off-shore area, strikes NW-SE, dips SE and includes most of the foreshock activity. The foreshock activity migrated to the northeastern part of the city of Pyrgos and took place on planes with a predominant direction NE-SW. The main shock ofM x =5.5 occurred in a focal plane located between the two above-mentioned areas. Strong motion records of significant shocks of the sequence show peak acceleration values on components consistent with the relevant fault plane solutions.

Furthermore, the observed macroseismic field has been compared with synthetic isoseismals computed by using a certain velocity model and the focal mechanism parameters of the main shock.

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References

  1. Ambraseys, N., Stavrakakis, G., andSimpson, K. (1993),Re-evaluation of Strong Ground Motion Data from Greece, ESEE Research Report, Imperial College of Science, Civil Engineering Dept., No. 93/3, 450 pp.

  2. Cerveny, V., andJansky, J. (1985),Fast Computation of Ray Synthetic Seismograms in Vertically Inhomogeneous Media, Studia Geophys. et Geod.29, 46–67.

  3. Comninakis, P. E., andPapazachos, B. C. (1986),A Catalogue of Earthquakes in Greece and Surrounding Area for the Period 1901–1985, Publication of the Geophysical Lab.1, University of Thessaloniki.

  4. Dziewonski, A. M., Ekström, G., andSalganik, M. P. (1994),Centroid-moment Tensor Solutions for January–March 1993, Phys. Earth Planet. Inter.82, 9–17.

  5. McGarr, A. (1984),Scaling of Ground Motion Parameters, State of Stress and Focal Depth. J. Geophys. Res.89, 6969–6979.

  6. Makropoulos, K., Drakopoulos, L., andLatoussakis, J. (1989),A Revised and Extended Earthquake Catalogue for Greece since 1900, Geophys. J. Inter.98, 391–394.

  7. Panza, C. F., andGuscito, M. (1982).Influence of Focal Mechanism on Shape of Isoseismals: Irpinia Earthquake of Nov. 23, 1980. Pure and Appl. Geophys.120, 577–582.

  8. Panza, G. F., Graglietto, A., andSuhaldoc, P. (1991),Source Geometry of Historical Events Retrieved by Synthetic Isoseismals, Tectonophysics193, 173–184.

  9. Panagiotopoulos, D. G. andPapazchos, B. C. (1985), Travel times of Pn waves in the Aegean and surrounding area, Geophys. J. R. Astr. Soc.80, 165–176.

  10. Papanastassiou, D., Stavrakakis, G. N., andDrakopoulos, J. (1994),A Study of the March 26, 1993, Pyrgos, Earthquake Sequence and its Tectonic Implications, Proceedings of the XXIV General Assembly of the European Seismological Commission, Sept. 19–24, 1994, Athens (in press).

  11. Papazachos, B. C. (1990),Seismicity of the Aegean and Surrounding Area, Tectonophysics178, 287–308.

  12. Papazachos, B. C., Kiratzi, A. A., andPapadimitriou, E. E. (1991),Fault Plane Solutions for Earthquakes in the Aegean Area, Pure and Appl. Geophys.136, 405–420.

  13. Stavrakakis, G. N., Kalogeras, I., andDrakopoulos, J. (1992),Preliminary Analysis of Greek Accelerograms Recorded at Stations of NOA's Network: Time Period 1973–1990, Publ. of the Institute of Geodynamics, No. 4, National Observatory of Athens, 432 pp.

  14. Stavrakakis, G. N., andPapanastassiou, D. (1995),Spatial-temporal Analysis of the Pyrgos, Peloponnisos, Southern Greece, Earthquake Sequence of 1993, Proceedings of the 5th International Conference on Seismic Zonation, Oct. 17–19, 1995, Nice, France, 1141–1148.

  15. Suhaldoc, P., Cernobori, L., Pazzi, G., andPanza, G. F. (1987),Synthetic isoseismals: Applications to Italian earthquakes. In Proc. CSEM Summer School on Seismic Hazard in Mediterranean Regions, Strassburg, July 21–Aug. 1, 1986, 205–228.

  16. Zahradnik, J. (1989),Simple Method for Combined Studies of Macroseismic Intensities and Focal Mechanism, Pure and Appl. Geophys.130, 83–97.

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Stavrakakis, G.N. Strong motion records and synthetic isoseismals of the Pyrgos, Peloponnisos, Southern Greece, Earthquake Sequence of March 26, 1993. PAGEOPH 146, 147–161 (1996). https://doi.org/10.1007/BF00876674

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Key words

  • Greece
  • strong motion
  • synthetic isoseismals