ISTerre seminar

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Bayesian level-set inversion of Bouguer gravity: application to the western Alps

Thursday 26 June 2025 - 15h30

Matteo Scarponi - LGL-TPE, Univ. Lyon
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The 3D western alpine crust presents a complex structure and remains subject of active geophysical investigation. Combining multidisciplinary gravity and seismic data is key to address subsurface complexity in terms of density and seismic velocity distribution. A Bayesian inversion of Bouguer gravity anomaly data (Zahorec et al. 2021) is set up. We introduce a priori information based on recent seismic tomography models (e.g. Nouibat et al. 2022), and use flexible physical constraints based on ρ-vS conversion laws (e.g. Brocher, 2005). To tackle the inverse problem, we adopt a level-set parameterization approach based on the available seismic tomography model information, and perform a Markov chain Monte Carlo (McMC) search, to explore complex laterally-heterogeneous 3D density structures with a low number of parameters. We explore existing trade-offs among density and geometry, benchmark existing tomographic models against gravity data, and explore new 3D density models for the crust along the western alpine collision boundary.

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Organizing team : Ondes et structures

Amphithéâtre Killian, Maison des Géosciences, 38400 Saint Martin d'Hères

Informations de visio :

https://univ-grenoble-alpes-fr.zoom.us/j/95496607088?pwd=UuSVyVX0SCxaFwJ8BOzQujEfEjydwi.1