Azimuthal anisotropy of the westernmost Mediterranean: New constraints on lithospheric deformation and geodynamical evolution

A new high-resolution azimuthally anisotropic Vs model beneath the westernmost Mediterranean is constructed based on Rayleigh wave dispersions obtained from 1186 broadband seismic stations. The model reveals several prominent features, including: (1) Anisotropy beneath Iberia inferred from surface waves is generally consistent with the results independently deduced from the analysis of SKS splitting, with fast velocity directions aligned close to E-W in most of the investigated area. (2) Vertically coherent mantle deformation is found across the vast majority part of the westernmost Mediterranean, namely, lithospheric deformation is coupled with the underlying asthenosphere. (3) Two anisotropic mantle layers are required to fit the data in a region in central Iberia, including part of the Duero and Tagus basins and the Central System. This is interpreted as denoting deformation in the mantle lithosphere related to the Alpine compressional regime. (4) The anisotropy in the Alboran Basin is complex and can be related to a deflected mantle flow pattern around the Alboran slab.(c) 2022 Elsevier B.V. All rights reserved.