Résumé
The tectonic evolution of the eastern Mediterranean region is largely influenced by two geological processes: subduction along the Hellenic arc and the westward extrusion of the Anatolian plate via the North Anatolian Fault. The interaction between these features, particularly at the termination of the North Anatolian Fault, has been widely studied but remains debated, largely due to the uncertain geometry of the African slab in the westernmost Hellenic arc. Here, we combined seismological and gravity datasets, revealing a complex deformation zone characterized by slab tearing, fault termination, and mantle upwelling. We processed two receiver function profiles, each about 500 km long and oriented perpendicular to the Hellenic trench, framing the southern tip of the North Anatolian Fault. These profiles reveal new slab geometry consistent with recorded seismicity, confirming slab break-off propagation. However, slab tearing alone cannot account for the regional mantle gravity field. Our findings indicate that asthenospheric upwelling at the slab tear location is necessary to explain the observed asymmetrical and bimodal gravity anomaly, coinciding with the North Anatolian Fault's termination and elevated surface heat flow. These insights enhance our understanding of deformation mechanisms in central Greece, suggesting that the slab tearing may have facilitated recent north-south extension in the Corinth rift, while asthenospheric flow concentrated strike-slip deformation on the North Anatolian Fault.
•Seismic and density models detail the western part of the African slab geometry.•African slab tearing is associated with an asthenospheric upwelling.•Slab tearing and associated mantle processes govern upper plate strain localization.•Slab geometry facilitates recent NS extension in the Corinth rift.•Asthenospheric upwelling localises strike-slip on the NAF.