SUMMARY

The Gulf of Corinth is one of the most active extensional regions in the Mediterranean area characterized by a high rate of seismicity. However, there are still open questions concerning the role and the geometry of the numerous active faults bordering the basin as well as the mechanisms governing the seismicity. In this paper, we use a 2D plane strain finite element analysis to constrain the upper crust rheology by modeling the available deformation data (GPS and geomorphology). We consider a SSW-NNE cross-section of the rift cutting the main active normal faults (Aigion, West Eliki and Off-Shore faults). The models run for 650 Kyrs assuming an elasto-visco-plastic rheology and 1.3 cm/yr horizontal extension as boundary condition (resulting from GPS data). We model the horizontal and vertical deformation rates and the accumulation of plastic strain at depth and we compare them with GPS data, with long term uplift rates inferred from geomorphology and with the distribution of seismicity, respectively. Our modeling results demonstrate that dislocation on high-angle normal faults in a plastic crustal layer plays a key role in explaining the extremely localized strain within the Gulf of Corinth. Conversely, the contribution of structures such as the antithetic Trizonia fault or the buried hypothetical sub-horizontal discontinuity are not necessary to model observed data. 2 CIANETTI ET AL. Key words: Finite-element methods – Rheology – Normal faultin