The western part of the Gulf of Corinth attracts attention due to its seismically active fault system and considerable seismic
hazard. Detailed studies of the seismic activity of the region have been carried out especially as part of the so-called Corinth
Rift Laboratory (CRL) Project. For standard earthquake locations, the CRL uses the HYPO algorithm and a special structural
model that is composed of homogeneous layers (Rigo et al., 1996). This model was derived from a passive seismic experiment
in a broader area around the western part of the Gulf. A significant part of the seismic activity is concentrated close to
the town of Aigion, which was damaged by a strong earthquake in 1995. A sequence of smaller earthquakes occurred to the south
of this town in the year 2001. In the present paper, we have used this sequence to derive an improved structural model for
the region in the vicinity of the town of Aigion. This new model is based on the minimization of travel-time residuals. In
particular, we used arrival times from a subset of 88 events recorded by at least 5 stations of the southern part of the CRL
network, had magnitudes of over 2.3, and were recorded at the nearest station (station code AIO). A variant of the method
of conjugate gradients has been used for this purpose. In comparison with the model derived by Rigo et al. (1996), the new
model is characterized by a higher νP/νS velocity ratio and by higher velocities to a depth of about 7 km. The new model was derived with the aim to get more accurate
locations of future events in the vicinity of the town of Aigion. 相似文献