Active faulting at the western tip of the Gulf of Corinth, Greece, from high-resolution seismic data

Arnaud Beckers (1, 2) , Aurélia Hubert-Ferrari (1) , Christian Beck (2) , Sarah Bodeux (1) , Efthymios Tripsanas (3) , Dimitris Sakellariou (3) , Marc de Batist (4)

1 Dept of Geography
2 ISTerre - Institut des Sciences de la Terre
3 HCMR - Hellenic Centre for Marine Research
4 UGENT - Universiteit Gent = Ghent University

The Gulf of Corinth is one of the fastest-spreading intra-continental rifts on Earth. GPS data indicate that the rift is currently opening in a NNE-SSW direction, with a rate of extension reaching up to 16 mm yr (super - 1) in its westernmost part. Although the rest of the offshore rift has been well studied, the western tip of the rift is still poorly explored. We present an accurate map of submarine faults in this area based on two high-resolution seismic reflection surveys (single-channel sparker). In the eastern part of the studied area, the sedimentary infill is affected by the known North Eratini, South Eratini, and West Channel faults. Further to the west, the seafloor is mostly flat and is bounded to the north by the normal, south-dipping, Trizonia fault. To the north, the shallower part of the Gulf shows to the east a diffuse pattern of normal and strike-slip deformation, which is replaced to the west by a 7.5 km long SE striking strike-slip fault zone, called the Managouli fault zone. To the westernmost tip of the Gulf, in the Nafpaktos Basin, two fault sets with different strikes are encountered; the one with a NE-SW strike exhibits a clear strike-slip component. The western tip of the Gulf of Corinth is the only part of the Corinth Rift where convincing evidence for strike-slip movement has been found. This fault pattern is likely related to the complex deformation occurring at the diffuse junction at the western tip of the Rift between three crustal blocks: Continental Greece, Peloponnese, and the Ionian Island-Akarnania block.

Mots clés: risk assessment; rifting; plate tectonics; neotectonics; natural hazards; Mediterranean Sea; Ionian Sea; Gulf of Corinth; geophysical surveys; geophysical profiles; geophysical methods; extension :tectonics; faults; geologic hazards; East Mediterranean; active faults; seismic methods; seismic profiles; seismic risk; seismic stratigraphy; strike-slip faults; surveys; tectonics; triple junctions

Domaines: Sciences de la Terre

Arnaud Beckers, Aurélia Hubert-Ferrari, Christian Beck, Sarah Bodeux, Efthymios Tripsanas, et al.. Active faulting at the western tip of the Gulf of Corinth, Greece, from high-resolution seismic data. Marine Geology, 2015, 360, pp.55 - 69. ⟨10.1016/j.margeo.2014.12.003⟩. ⟨hal-01415480⟩