![]() ![]() State-of-the-art 3D P-Cable seismic data were acquired to characterize the geometry and linkage of faults in the SMT and SOT. Conversely in the alternative model, the deformation is predicted to be compressional associated with a regional blind thrust that reactivated detachment faults along the continental margin. One model predicts that the deformation is transpressional in a predominantly right lateral fault system with left lateral step-overs. 3Nevada Seismological Laboratory, University of Nevada, Reno, Reno, NV, United Statesĭeformation observed along the San Mateo (SMT) and San Onofre trends (SOT) in southern California has been explained by two opposing structural models, which have very different hazard implications for the coastal region.2Faculty of Geological Sciences, Complutense University of Madrid, Madrid, Spain.1Scripps Institution of Oceanography, University of California, San Diego, La Jolla, CA, United States.We propose that the L-O-S tectonic system prolongs the NAF system and may progressively evolve as the future plate boundary.James J. ![]() The Oreoi Channel is controlled by NE-SW-striking faults with a right-lateral component and the Lichades Area displays several fault with oblique direction and pure extension. The Skiathos basin development shows indications of transtensive deformation. This detailed structural analysis together with the synthesis of seismic activity allow to propose a tectonic map with new insights on the recent deformation of the key-area "L-O-S" in the south-western prolongation of NAF. Finally, many earthquakes focal mechanisms located in the Skiathos Basin and the Oreoi Channel indicate strike-slip faulting, with a right-lateral motion along the NE-SW direction. Some normal faults, oriented NE-SW and W-E, have been identified in the basin. The Skiathos Basin presents two main depocenters individualized by areas of rising acoustic basement. The Skiathos Basin is a newly discovered structure from our seismic dataset that is separated from the Skopelos Basin by a NE-SW striking acoustic ridge. In the south-east, the Oreoi Channel is delineated by the Oreoi Fault, a mainly onshore normal fault which is dipping towards north-west. The seismic profiles highlight normal faults of different ages with a NE-SW direction. The Oreoi Channel is a marine straight linking the Lichades Area and the Skiathos Basin. One of the largest sub-active to active fault is striking NE-SW, parallel to the Oreoi Channel, and thus strongly oblique to the main rift deformation. The deformation in the Lichades Area is dominated by numerous active normal faults striking W-E or WNW-ESE and showing metric-scale offsets (up to 5 m.) within the Holocene sequence. The interpretations from these datasets emphasize the evolution of the deformation of the North Evia domain, in particular, along the NE-SW striking lineament "Lichades Area - Oreoi Channel - Skiathos Basin" (L-O-S). We also analysed several seismicity catalogues in order to connect the recent structures from seismic lines to active tectonics over the region. Our study is mostly based on new very-high-resolution seismic reflection profiles (Sparker) acquired during the WATER surveys (Western Aegean Tectonic Evolution and Reactivations) in July-August 20, onboard the R/V "Téthys II". The whole zone experience a relative high seismicity with strike-slip focal mechanisms, especially right-lateral displacements along NE-SW-striking faults, which are mainly located between the North Evia domain and the Southern Thessaly. This major extensional area is mainly constituted by the Corinth rift and the North Evia domain, our study area. In the western prolongation of this termination, there is a wide domain characterised by distributed deformation. In the NAT, the NAF termination is located near to the Sporades Islands. The western termination of NAF is currently located in the North Aegean Trough (NAT) where NAF displays a NE-SW direction. The NAF westward propagation during Neogene and Quaternary times delineates the plate boundary between Eurasia and Anatolia-Aegean. Its right-lateral strike-slip fault initiated in eastern Turkey 13 Ma ago. ![]() The North Anatolian Fault (NAF) is one of the major active structures in the Eastern Mediterranean. ![]()
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