36-months postdoc position at CEA (France)

[Audrey Gailler]

Dear all,

The French Alternative Energies and Atomic Energy Commission (CEA, France) is looking for a post-doctoral candidate for a 36-month study on the probabilistic analysis of submarine slope stability and the 3D and 2D modeling of tsunamis due to associated landslides.

Please find a detailed description of the offer below.

Best regards,

----------------------------------------------------
Audrey Gailler
CEA DAM/DIF/DASE/LDG
Laboratoire Etudes Géophysiques et Aléas
91297 Arpajon Cedex
FRANCE

e-mail : audrey....@cea.fr

 

Postdoc position at CEA (36 months):

Analysis of Mururoa atoll slope stability using a probabilistic approach, and construction of a weighted database of landslide tsunami models for the Nice region.

 

General context :

Many tsunamis, whether following strong earthquakes or not, are generated or accentuated by the triggering of submarine landslides. This was the case for several historical tsunamis (Nice 1564 and 1979; Liguria sea 1887; Papua 1998; Java 2012; Polynesia 1979), which impacted several kilometers of nearby coastline.  Methods for assessing slope stability are of major interest in assessing the probability of failure and the danger associated with such events.

Postdoc objectives :

The aims of the post-doctorate are towfold:

-carry out a 2D and 3D slope stability analysis on the northeast zone of Mururoa, including a probabilistic aspect (e.g., SAMU_3D code; Leynaud & Sultan, 2010). Various potential landslide magnifiers with a safety factor will be defined (geometry, volume), which will feed into the tsunami simulation.

-assess the potential inundation impact of gravity-driven tsunamis on the heavily instrumented region off Nice, based on 3D and 2D modeling.

Postdoc program :

The first year of the post-doctorate will consist in assessing the feasibility of the study in view of the constraints on the number and quality of available data (fine bathymetry, lithological structure, geomechanical parameters of sediments, fracture mapping, etc.) from which the definition of soil parameters representative of failure surfaces will derive. A probabilistic analysis of slope stability will then be undertaken to refine conventional assessments by integrating into the result the variability of specific data linked to the site of interest. In particular, the aim will be to quantify critical slip surfaces in terms of slip probability as accurately as possible; and to estimate safety factors for critical failure surfaces down to a given depth.  This work will mainly be supervised by Ifremer, which has developed the SAMU_3D software (Sultan et al., 2007) to tackle this problem. The open-source tool SCOOPS3D (https://www.usgs.gov/software/scoops3d) will also be used for comparison.

During the 2^nd and 3^rd years, the aim of the post-doc will be to simulate tsunamis generated by underwater debris avalanches using DualSPHysics, using this landslide database. The results will be compared with those of the VOF OpenFoam code with regard to the desired application (ongoing study). The postdoc will also develop the coupling between DualSPHysics and the CEA's 2D tsunami code (Heinrich et al., 2021), to propagate the tsunami over long distances and simulate the break-up on distant coasts, and then feed the DualSPHysics vs OpenFoam comparison.

In parallel with the study on French Polynesia, the post-doc will focus on the heavily instrumented region off Nice airport, with the aim of completing the construction of a weighted database of landslide tsunami models for the area. The assessment of the potential hazard in terms of flooding on the Côte d'Azur could be the subject of international communications and rank A publications.

Skills required :

This project requires a good grounding in geophysics and numerical modeling. The candidate will need to be rigorous, creative and able to interact with a variety of people.

Place of work :

1^st year at Ifremer, Brest (29 – France); 2^nd and 3^rd year at CEA (Département Analyse Surveillance Environnement), Bruyères-le-Châtel (91- France). Allow two months for CEA clearance procedures.

Application Deadline : September 30^th, 2024.

Potential start date : November/December 2024 or early 2025.

Contact : Audrey Gailler, audrey....@cea.fr