Missions

The Laboratoire Magmas et Volcans (LMV) in Clermont-Ferrand, France, is seeking to appoint a postdoctoral researcher in the volcanology group. The successful candidate will work in collaboration with geophysicists (Valerie Cayol, Anne Barnoud and Lydie Gailler) and mathematicians (Olivier Bodart and P.H. Cocquet) on a project (DGMod) funded by the ANR, which is dedicated to the development of a new generation of joint InSAR and gravity inversions.

Activités

In this project, we propose to do a proof of concept by first implementing the gravity anomaly using a boundary element method for homogeneous media (Cayol et al., 1997), before switching to a fictitious domain method for heterogeneous media (Bodart et al., 2016) in order to account for fractures or reservoir-type sources located in a fully three-dimensional medium. Both methods are currently capable of calculating stresses and strains in the elastic medium. We will adapt them to the modelling of gravity changes, following the approach indicated by Bonafede and Mazzanti (1998), and followed by Trasatti and Bonafede (2008) and Currenti et al. (2008). To characterize the sources, these models will need to be combined with inversions. We will use near-neighborhood inversions (Sambridge et al., 1999a and 1999b), already implemented for the inverse modeling of displacement data (Fukushima et al., 2005).
Both approaches will be benchmarked on analytic solutions for fractures (Okubo, 1992) and ellipsoids (Nikkhoo and Rivalta, 2022). They will applied to the reinterpretation of the 1998 eruption of the Piton de la Fournaise volcano, as well as to three eruptions that occurred in June, July and August 2019 and were followed by 3 measurement campaigns.

Compétences

the candidate should have some of the following expertises:
• Gravimetry changes data processing and modelling
• InSAR data processing and modelling
• Rock mechanics, and inversion
• Computation: Linux, Matlab or Python

Contexte de travail

Laboratoire Magmas et Volcans is located in Clermont-Ferrand, in central France. This region offers excellent opportunities for outdoor activities and has a low cost of living. The laboratory focuses on understanding magmatic processes, examining everything from the structure of the deep mantle to surface volcanic activity. The Laboratory consists of about 60 tenured researchers. The research of the volcanology team ranges from the transfer and storage of magmas to the internal dynamics of volcanoes, eruptive processes and implications of this activity in terms of hazards and risks. Our approaches consist of coupling observations and measurements (field and remote sensing), laboratory experiments and numerical modelling (see page https://lmv.uca.fr/volcanology/).

Contraintes et risques

No particular constraints