EGU23-12491, updated on 14 Jun 2023
EGU General Assembly 2023
© Author(s) 2023. This work is distributed under
the Creative Commons Attribution 4.0 License.

Adjoint Tomography of the Italian Lithosphere

Federica Magnoni1, Emanuele Casarotti1, Dimitri Komatitsch2, Raffaele Di Stefano1, Maria Grazia Ciaccio1, Carl Tape3, Daniele Melini1, Alberto Michelini1, Antonio Piersanti1, and Jeroen Tromp4
Federica Magnoni et al.
  • 1Istituto Nazionale di Geofisica e Vulcanologia (INGV), Rome, Italy
  • 2CNRS Laboratory of Mechanics and Acoustics, Marseille, France
  • 3University of Alaska Fairbanks, Fairbanks, AK, USA
  • 4Princeton University, Princeton, NJ, USA

The evolution and state of geological structure at Earth’s surface is best understood with an accurate characterization of the subsurface, where fluid distribution plays a key role. We present high-resolution seismic tomographic images of tectonic and geological features of the Italian lithosphere based on ground motion recordings and obtained through an iterative procedure. Enhanced accuracy is enabled by state-of-the-art three-dimensional wavefield simulations in combination with an adjoint-state method. The resulting tomographic model characterizes the subsurface structure in terms of compressional and shear wavespeed values at remarkable resolution, corresponding to a minimum period of ~10 s. As primary findings of our work, images of the lithospheric structure in Central Italy are consistent with recent studies on the distribution of fluids and gas (CO2) within the Italian subsurface, allowing us to infer the presence of deep melted material that induces shallow gas fluxes, or traps and deep storage of gas that can be correlated with seismicity. We illuminate Mt. Etna volcano and support the hypothesis of a deep reservoir (~30 km) feeding an intermediate-depth magma-filled intrusive body, which in turn is connected to a shallow chamber. We also investigate the intriguing features of the Adriatic plate offshore of the eastern Italian coast. Tomographic evidence reveals a structure of the plate made of two distinct microplates with different fabric and behavior, and separated by the Gargano deformation zone, indicating a complex lithosphere and tectonic evolution.

How to cite: Magnoni, F., Casarotti, E., Komatitsch, D., Di Stefano, R., Ciaccio, M. G., Tape, C., Melini, D., Michelini, A., Piersanti, A., and Tromp, J.: Adjoint Tomography of the Italian Lithosphere, EGU General Assembly 2023, Vienna, Austria, 23–28 Apr 2023, EGU23-12491,, 2023.