Transforming the Eastern Mediterranean: The Aegean-Cyprus Slab Tear

The Aegean and Western Anatolian region has experienced widespread extension since the Late Oligocene, characterized by southward migration of arc volcanism, exhumation, and basin formation. Recent seismic data have revealed a significant tear between the subducted Aegean and Cyprus slabs. Such a tear is expected to disrupt local mantle flow, yet its impact on surface processes like topography, deformation, and magmatism remains poorly understood. In this study, we develop 4D geodynamic models to explore the effects of slab tearing in this part of the eastern Mediterranean region. Our model results demonstrate that tear-induced mantle flow aligns closely with a range of geological and geophysical observations, including a counterclockwise toroidal flow beneath Western Anatolia. The slab tearing also triggers rapid transient mantle upwelling, resulting in dynamic topographical uplift. Additionally, it facilitates the influx of hot asthenosphere from behind the subducted slab, promoting partial melting and widespread magmatism across the region. The model further indicates that the overlying continent is under extension, with the extension direction transitioning from NE-SW in Western Anatolia to N-S towards the Aegean trench. Our findings reconcile with observed geological anomalies in the Aegean zone and Western Anatolia, such as the distribution of volcanic activity and patterns of crustal deformation. This correlation not only validates our model but also provides new insights into the complex interactions between slab dynamics and surface expressions, enhancing our understanding of how slab discontinuities manifest geological phenomena.