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Slip Model
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Athens Earthquake Sequence
On 7 September 1999, an earthquake of magnitude Mw = 6.0 occurred in the Aspropirgos basin located close to the Saronic Gulf as well as to the city of Athens, the capital of Greece. This event was the strongest that happened in a region of low seismic activity. In this region no evidence of important earthquakes was reported by historical catalogues or other sources, therefore this area was considered to be of low seismic risk. Although the earthquake magnitude was moderate the caused damage was very serious. There were 143 killed people, a great number of wounded and several thousands of people became homeless. Consequently it may be considered as one of the most disastrous earthquakes that occurred in Greece during the last centuries.
The seismogenic area is situated next to the eastern edge of the Gulf of Corinth where important earthquakes occurred during the last 20 years. The Gulf of Corinth is characterized by E-W trending, north-dipping normal faulting and by a NNE-SSW direction of extension with a rate of about 1 cm/yr. On 1981 three major earthquakes of magnitudes MS=6.7, 6.4 and 6.4 occurred in the easternmost part of this Gulf. Focal mechanisms of these events revealed normal faulting trending E-W dipping north for the two first events and south for the last event of 4 March. The constrained focal depths vary between 8 and 10 km. Surface breaks were observed and were related to the second and the third event. Coseismic slip reaches 150 cm but the more typical range is 50-70 cm. The aftershock activity is mainly concentrated at the eastern edge of the Gulf (Fig. 1), close to the Vill station, and reaches until the village of Plataies (Pl).
The Cornet seismological permanent network has been installed
since 1995 around the eastern Gulf of Corinth by the Department of Geophysics
of the University of Athens. For the period 1996-1999 approximately 5000 events were recorded, while more than 2000
were located in the Gulf and the surrounding area. During the operation
period of the Cornet network there was no clear evidence of seismic activity
in the Aspropirgos basin, until the earthquake sequence of 7 September.
The Cornet network has recorded four foreshocks, the main shock of 7 September
1999 and numerous aftershocks.
The calculated slip model revealed strong directivity to the East
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