We present a novel three-dimensional anisotropic seismic tomography of the Mediterranean region, achieved through the simultaneous inversion of P-wave travel times and SKS splitting intensity. This dual approach has allowed us to obtain a comprehensive tomographic model that not only delineates the primary structural features of the area but also sheds light on its tectonic evolution. Our findings reveal that the isotropic component of the model is dominated by fast anomalies linked to retreating, stagnant, and detached slab segments, while slower mantle structures are associated with slab windows and back-arc basin formation. The recovered anisotropic patterns provide crucial insights into the tectonic history of the Mediterranean, highlighting periods of collision and tectonic relaxation. Notably, we observe a range of plunge angles, with both near-horizontal and steeply dipping fabrics present in different regions, reflecting the influence of horizontal and vertical asthenospheric flows. By interpreting the high-velocity zones as subducting lithosphere, we constructed a detailed 3-D model of the main slabs and analyzed the surrounding P-wave anisotropic patterns. This work represents the first comprehensive anisotropic tomography of the entire Mediterranean, underscoring the significance of seismic anisotropy in constraining the upper mantle structure and elucidating the region's tectonic dynamics throughout its geological history.

Seismic anisotropy is key to constrain mantle flow, but it is challenging to image and interpret it. To better understand the robustness of anisotropy tomography, we create a 2-D ridge-to-slab geodynamic model and compute the associated fabrics. Using the resulting 21 elastic constants we compute seismic waveforms, which are inverted for isotropic and radially anisotropic structure. We test the effects of different data coverage and levels of regularisation on the resulting images and on their geodynamical interpretation. The retrieved isotropic images exhibit substantial artificial slab thickening and loss of the slab’s high velocity signature below ~100 km depth. Our results also show that regularisation and data coverage strongly control the characteristics of the retrieved depth-age dependency of anisotropy, leading to an artificial flat depth-age trend shown in existing anisotropy tomography models. Greater data coverage and additional complementary data types are needed to improve the resolution of (an)isotropic tomography models.