GNGTS 2024 - Atti del 42° Convegno Nazionale

Session 1.3 GNGTS 2024 Upper Mantle structure in the Tyrrhenian and Ionian basins (Central Mediterranean) from P and S receiver functions C. Montuori (1) , S. Monna (1) , F. Frugoni (1) , C. Piromallo (1) , M. De Caro (1) , A. Giuntni (1) , G. Marinaro (1) , V. Cormier (2) and L. Vinnik (3) (1) Isttuto Nazionale di Geofsica e Vulcanologia, Rome. Italy (2) Dept. of Physics, University of Connectcut. USA (3) Insttute of Physics of the Earth, Moscow. Russia We investgate the upper mantle discontnuites below the Tyrrhenian and Ionian basins by applying the P and S receiver functon techniques to waveforms from broadband statons of the RSN network (Italy), located in Sicily, Ustca Island and Sardinia. These basins, with distnct characteristcs in terms of age, origins, and crust-mantle structure, form part of the Central Mediterranean convectve system. They are situated in diferent geological setngs—the back-arc for the Tyrrhenian basin and the fore-arc for the Ionian basin—relatve to the Calabrian slab. We model the 1D velocity structure below each staton down to 250 km depth by joint inversion of P and S receiver functons through the Generalized Simulated Annealing method (Tsallis, 1988; Tsallis & Stariolo, 1996). Land-based observatons are complemented with the analysis of data recorded by a broadband seismometer hosted on the NEMO-SN1 permanent observatory at 2100 m b.s.l (Western Ionian Regional Facility of EMSO ERIC, www.emso.eu ) . We show preliminary results for the Moho and Lithosphere-Asthenosphere-Boundary depth in the Ionian basin and integrate them with observatons for the Tyrrhenian basin from our previous work (Monna et al., 2019). We detect the mantle transiton zone (MTZ) discontnuites (the ‘410’ and ‘660’) below the basins based on the receiver functons stacks and speculate on the origin of the observed MTZ thickness variatons.