The Influence of the North Anatolian Fault and a Fragmenting Slab Architecture on Upper Mantle Seismic Anisotropy in the Eastern Mediterranean

The eastern Mediterranean hosts, within the span of a few hundred kilometers, extensional, strike-slip, and collision tectonics above set fragmenting subducting slabs. Slab roll-back, toroidal flow, lithospheric dripping/delamination processes are also believed to be operating. Associated asthenospheric flow deformation expected manifest as seismic anisotropy, measurable via study SKS shear wave splitting. Surprisingly, previous splitting investigations have resolved only long wavelength patterns anisotropy in region, interpreting them large-scale flow; moreover, no anisotropic signature has been associated with North Anatolian Fault (NAF), unlike other major strike-slip plate boundaries worldwide. We present 29-year record observations, revealing hitherto-unrecognized short-length-scale variations backazimuthal parameters that attest multi-layered anisotropy. Lithospheric beneath NAF exhibits fast directions either fault-parallel or intermediate between principle extensional strain rate axis fault strike, diagnostic relatively low-strained transcurrent mantle zone. Elsewhere, is consistent through tomographically imaged slab gaps, driven by Hellenic trench retreat. Evidence for westward asthenosphere driving motion lacking. Shorter delay times nulls central Anatolia suggest weaker azimuthal asthenosphere, supporting models invoke vertical (lithospheric dripping/asthenospheric upwelling). Thus, we conclude signal more closely reflects deformation, complex architecture geodynamic diversity region than previously recognized.