Mantle Dynamics of the Eastern Mediterranean and Middle East: Constraints From P-Wave Anisotropic Tomography

High-resolution images of P-wave anisotropic tomography beneath the Eastern Mediterranean and Middle East are determined by inverting a large number of high-quality P-wave arrival times. Our results clearly show along-strike variations of subducting slabs in the Hellenic subduction zone. At least three high-velocity anomalies are imaged beneath and behind the north Hellenides, which are associated with the subducting Hellenic slab at different stages, while in regions further south, a single slab is revealed that has subducted down to a depth of ~1,100 km. The slab feature is not prominent in the Cyprus subduction zone, but a fine-scale high-velocity structure is revealed beneath the central Anatolia, which may reflect the detached Cyprus slab. Trench-parallel fast-velocity directions occur in the forearc mantle wedge of the Hellenic subduction zone, which may reflect mantle flow induced by slab curvature. In the backarc north Aegean and westernmost Anatolia, dominant NNE-SSW to N-S fast-velocity directions exist in the shallow mantle, which accord well with the extensional direction of present deformation at the surface, suggesting a vertically coherent deformation in the lithosphere. Our results reveal a large-scale mantle flow beneath western Arabia, which is possibly related to the Zagros and Caucasus orogens and westward motion of the Anatolia lithosphere. The Arabian lithospheric plate is thinner beneath the Zagros than that under the Mesopotamian Foredeep, suggesting that a large portion of the crust was scrapped off from the subducted Arabian lithosphere during the Zagros orogen.