PhD position «Multiphysics detection and modelling of abrupt mass changes in low-energy wet volcanoes»
LabEx LIO
State University (France), Browse similar opportunities
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State University (France), Browse similar opportunities
Short description
The PhD position is proposed for a 3-year period (36 months). The legal net salary is €1768 per month (plus social benefits). An annual €2 000 package for travels and equipment will be allotted. The candidate is expected to submit a thesis manuscript to the university of Lyon for a formal presentation in front of a jury before the end of the 3-yr period.
Starting date of the contract: October the 1st, 2021
Research project (1/2 page – 1 page)
Low-energy active wet volcanoes recently became the focus of much attention for the risk they represent [1]. Indeed, most fatalities that occurred during the last two decades were caused by unexpected local explosions due to overpressure in the shallow hydrothermal system of touristic volcanoes with moderate activity [2]. This type of hazard is now recognized as a main topic by the volcano community [3]. In 1993, the explosive event of the Galeras volcano killed 9 people, including 6 volcanologists. More recently, in 2014, an unexpected explosive event killed 63 hikers on the Ontake volcano in Japan [4]. These local events are not likely to provoke regional disasters, but they however represent high-risk situations for people on site. Such is the case of many volcanoes, including La Soufrière of Guadeloupe localized in a National touristic park.
In the recent literature concerning the Ontake event, it is widely admitted that these explosive hydrothermal events may have a rapid and silent onset which can be as short as some hours or days. Presently, both the location and the date of occurrence of such events are considered impossible to predict and the physics of these phenomena remains largely undocumented. For the first time, one such event was described in details by ourselves [5] and could be studied by means of different kinds of data (vent temperature, seismic noise tomography and muon tomography). This study revealed that potentially explosive steam pockets originate from complex interactions between the fracture network that collects thermal energy in the deep hydrothermal system and the shallow network of large open fractures driving hot fluids to the atmosphere. In volcanoes like La Soufrière, thermal energy is transported by the steam phase and multiphase flows occur in the fracture network. Complicated phenomena then appear, such as density wave oscillations, bubble nucleation in developed bubble wakes, bubble detachment thresholds. Because of its high bulk density and compressibility, the liquid-gas mixture may oscillate and transmit strong seismic vibrations to the surrounding rock [5].
The main objective of the project is to document the sudden appearance and the dynamics of steam pockets in the shallow hydrothermal system of wet volcanoes. Predicting the time-origin of this type of events is of a primary importance with respect to risk mitigation. This is particularly challenging because the time constants of onset of the phenomena are particularly short. The study will largely rely on the monitoring of La Soufrière lava dome with cosmic muon tomography which allows to monitor density changes in the whole lave dome [6]. Other geophysical experiments will be done to complement the muon data: seismic noise recording to detect and localize hydrothermal sources of noise and thermodynamic monitoring of the main active vents on the summit of the volcano. Numerical models and data inversion will be done to constrain physical models of the phenomena. These models will consider multiphase flows in fracture networks subject to intense heat flows. Depending on the amount of energy to evacuate, different flow regimes may occur with, eventually, abrupt bifurcations producing dangerous surface phenomena. Stochastic approaches will be used to simulate flows in random networks and powerful computational resources.
[1] Caudron, Corentin, Thomas Lecocq, Devy K. Syahbana, Wendy McCausland, Arnaud Watlet, Thierry Camelbeeck, and Alain Bernard. "Stress and mass changes at a “wet” volcano: Example during the 2011–2012 volcanic unrest at Kawah Ijen volcano (Indonesia)." Journal of Geophysical Research: Solid Earth 120, no. 7 (2015).
[2] Phillipson, G., Sobradelo, R. & Gottsmann, J. Global volcanic unrest in the 21st century: an analysis of the first decade. Journal of Volcanology and Geothermal Research 264, 183–196 (2013).
[3] Erfurt-Cooper, P. Active Hydrothermal Features as Tourist Attractions, Cambridge University Press, Cambridge (2017).
[4] Oikawa, T. et al. Reconstruction of the 2014 eruption sequence of Ontake Volcano from recorded images and interviews. Earth,
Planets and Space 68, 79 (2016).
[5] Le Gonidec, Yves, Marina Rosas-Carbajal, Jean de Bremond d’Ars, B. Carlus, J-C. Ianigro, Bruno Kergosien, J. Marteau, and Dominique Gibert. "Abrupt changes of hydrothermal activity in a lava dome detected by combined seismic and muon monitoring." Scientific Reports 9 (2019).
[6] Marteau, Jacques, D. Gibert, N. Lesparre, F. Nicollin, P. Noli, and F. Giacoppo. "Muons tomography applied to geosciences and volcanology." Nuclear Instruments and Methods in Physics Research Section A: Accelerators, Spectrometers, Detectors and Associated Equipment 695 (2012).
Research field(s)
The candidate should have a significant knowledge in the following domains: Physics of complex systems, heat and mass transfers, numerical modelling, non-linear signal processing, multiscale analysis, data inversion, and dynamic tomography.
Thesis supervisor and contact
Name: Prof. Dominique GIBERT
LGL-TPE (UMR 5276) and Lyon Observatory (UMS 3721 CNRS/INSU), Lyon 1 University, F-69622 Villeurbanne, France
Phone number: +33 6 27 40 00 32
Email: dominique.gibert@univ-lyon1.fr
Working environment
Job location and description
The host laboratory will be the LGL Geosciences laboratory located on the La Doua Campus of Lyon 1 University in Villeurbanne with strong interactions with the IP2I Particle Physics laboratory located on the same campus. The candidate will also work with the others teams involved in the La Soufrière ANR MeGaMu research program (2020-2025).
Team
Presently, no PhD student is under the supervision of Prof. Dominique Gibert.
The candidate will interact with colleagues from LGL (seismologists, data scientists), IP2I (particle physicists), Rennes 1 University ( seismics, volcanology), and the Volcano Observatory of Guadeloupe (thermochemistry, thermophysics, volcanology), INRIA Bordeaux (data scientist, physics of complex systems).
Allocated resources
The project heavily relies on massive numerical time-space modelling using the computing facilities of the CCF/Cluster.
Recent publications of the team
Moretti, Roberto, Jean-Christophe Komorowski, Guillaume Ucciani, Séverine Moune, David Jessop, Jean-Bernard de Chabalier, François Beauducel et al. "The 2018 unrest phase at La Soufrière of Guadeloupe (French West Indies) andesitic volcano: Scrutiny of a failed but prodromal phreatic eruption." Journal of Volcanology and Geothermal Research 393 (2020): 106769.
Allali, Meriem, Patrick Portecop, Michel Carles, and Dominique Gibert. "Monitoring the post-containment COVID-19 crisis in Guadeloupe: Early-warning signals of destabilisation through bootstrapped probability density functions." medRxiv (2020).
Allali, Meriem, Patrick Portecop, Michel Carlès, and Dominique Gibert. "Prediction of the time evolution of the COVID-19 disease in Guadeloupe with a stochastic evolutionary model." medRxiv (2020).
Le Gonidec, Yves, Marina Rosas-Carbajal, Jean de Bremond d’Ars, Bruno Carlus, J-C. Ianigro, Bruno Kergosien, J. Marteau, and Dominique Gibert. "Abrupt changes of hydrothermal activity in a lava dome detected by combined seismic and muon monitoring." Scientific reports 9, no. 1 (2019): 1-9.
Boukerbout, H., A. Abtout, Dominique Gibert, B. Henry, B. Bouyahiaoui, and M. E. M. Derder. "Identification of deep magnetized structures in the tectonically active Chlef area (Algeria) from aeromagnetic data using wavelet and ridgelet transforms." Journal of Applied Geophysics 154 (2018): 167-181.
Marteau, Jacques, Jean de Bremond d'Ars, Dominique Gibert, Kevin Jourde, J-C. Ianigro, and Bruno Carlus. "DIAPHANE: muon tomography applied to volcanoes, civil engineering, archaelogy." Journal of Instrumentation 12, no. 02 (2017): C02008.
Rosas‐Carbajal, Marina, Kevin Jourde, Jacques Marteau, Sébastien Deroussi, Jean‐Christophe Komorowski, and Dominique Gibert. "Three‐dimensional density structure of La Soufrière de Guadeloupe lava dome from simultaneous muon radiographies and gravity data." Geophysical Research Letters 44, no. 13 (2017): 6743-6751.
Lopes, Fernando, Jean-Louis Le Mouël, and Dominique Gibert. "The mantle rotation pole position. A solar component." Comptes Rendus Geoscience 349, no. 4 (2017): 159-164.
Jourde, Kevin, Dominique Gibert, Jacques Marteau, Jean de Bremond d’Ars, and Jean-Christophe Komorowski. "Muon dynamic radiography of density changes induced by hydrothermal activity at the La Soufrière of Guadeloupe volcano." Scientific reports 6 (2016): 33406.
Rosas-Carbajal, Marina, Jean-Christophe Komorowski, Florence Nicollin, and Dominique Gibert. "Volcano electrical tomography unveils edifice collapse hazard linked to hydrothermal system structure and dynamics." Scientific reports 6 (2016): 29899.
Description of LabEx LIO
In 2011, The Lyon Institute of Origins LabEx was selected following the first “Laboratory of Excellence” call for projects, part of the “Investissement d’Avenir” program for forward-looking research. It is one of 12 LabExes supported by the University of Lyon community of universities and establishments (COMUE). LIO brings together more than 200 elite researchers recruited throughout the word and forming 18 research teams from four laboratories in the Rhône-Alps region, all leaders in their fields, under the auspices of the University Claude Bernard Lyon 1 (UCBL), the Ecole Normale Supérieure de Lyon, and the CNRS. LIO’s goal is to explore questions about our origins, operating in a broad field of study that ranges from particle physics to geophysics, and includes cosmology, astrophysics, planetology and life
Selection process
The successful candidate will be selected in partnership with the Doctoral School « Physics and Astrophysics » of the University of Lyon.
Condition for admission to doctoral studies
The candidates must hold a national master degree or equivalent.
Application deadline
May the 1st, 2021
Requested documents for application
The candidates must submit their application with (i) their academic curriculum of the last three years, (ii) a letter of motivation, (iii) a CV and (iv) a letter of recommendation, to labex.lio@universite-lyon.fr before May the 1st, 2021.
Candidates on the short list will be informed by the end of May. They will be interviewed in June.
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