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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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
- strong motion
- synthetic isoseismals