Insight into the lithospheric velocity structure of the Adria plate from joint teleseismic and ambient noise tomography

In the complex tectonic puzzle of the central-Mediterranean, where major plates such as Africa and Eurasia interacted- shaping the Alpine, Apennines, Dinarides and Hellenides orogenic belts- the Adria  microplate  plays a crucial role. Its subduction is characterized by an outward-dipping double vergence: westward below the Apennines and eastward below the Dinarides-Albanides-Hellenides system, defining the peculiarity of these orogens. The Adria microplate influence has impacted the evolution, subduction dynamics, crustal deformation, and seismicity of this unique geodynamic region (Dewey et al., 1989, Royden and Faccenna, 2018; Kissling et al., 2024).  

To better understand the deformation and the intricate geodynamics of the Adria microplate, the AdriaArray project builds upon the success of the AlpArray initiative by extending seismic coverage to the eastern central Mediterranean, particularly along the Dinarides-Albanides-Hellenides belt. AdriaArray provides new and high-resolution seismic data addressing previous gaps and enabling the computation of new detailed velocity models that span from the crust to mantle depths. The main goal of this work is to obtain high-quality images of the Albanides-Hellenides system, a region historically limited by data scarcity.

In light of this, we are currently analyzing AdriaArray continuous seismic data from more than 1100 broadband seismic stations to develop a large-scale high-resolution surface-wave tomographic model. Our approach involves a joint inversion of teleseismic and ambient noise surface wave dispersion measurements, implemented through the Seislib code (Magrini et al., 2022). We compile surface-wave velocities to obtain both Rayleigh and Love phase and group velocities maps over a wide period range (3-150s). The final step involves applying a Bayesian approach to convert these velocity maps into a 3D shear-wave velocity model. The strength of this study lies in the extensive dataset, improved  geometric coverage, and the use of joint inversion techniques, allowing high-resolution imaging at a wide range of depth (from the crust to upper mantle).

Preliminary results, including cross-correlations of ambient noise, surface-wave dispersion curves derived from ambient noise and teleseismic events, and Rayleigh and Love phase/velocity maps of the studied area, will be presented.