CNRS - Centre de Recherches Pétrographiques et Géochimiques

Homepage: https://crpg.univ-lorraine.fr/en/home/

In mountainous landscapes, bedrock landslides represent a major natural hazard that threatens the safety of populations and infrastructure. They are also widely recognized as the primary erosion mechanism driving hillslope erosion and landscape evolution in active mountain regions (e.g. Burbank et al., 1996). Diversity in rock weakening and geologic setting leads to a large diversity of landslides types, involving distinct depths and geometry of the failure surface. It also leads to a wide range of deformation rates, from rapid and catastrophic landslides to extremely slow deformations (a few m/kyr) (Hungr et al., 2014). In this project, we hypothesize that the contribution of slow-moving landslides (SML) represents an underestimated, if not the missing, source of long-term erosion in mountainous landforms. If this hypothesis is verified, it should represent a significant paradigm shift in our view of how mountain hillslopes are eroded. With this project, we aim to improve our knowledge on the response of slow landslides to climatic, seismic and anthropogenic forcing, and to explore the insufficiently-estimated hazard induced by SML. The processes that control the deformation rate of the SMLs are complex and not fully understood. However, phases of deformations usually involve major groundwater forcing (e.g. Agliardi et al., 2020). Hence, the control of cyclic pore pressure increase must be introduced in any numerical model that aims at representing SML behaviour. Currently, discrete element models seem to provide the critical features needed to describe many of the mechanisms and deformation processes at the origin of landslides. Building upon our recent work (Huber et al., 2024), we propose to explore the SML response to hydrological forcing using the open source code YADE-DEM (Angelidakis et al., 2024). The modeling strategy will follow several steps: 1. Introducing pore water effects in the existing model; 2. Introducing time-dependent deformation processes; 3. Reproducing the behaviour of different landslides based on their respective geometry/structure, rheology; 4. Exploring the sensitivity of SMLs to varying forcing parameters, for example varying the amplitude of the seasonal water table rise as well as considering seismic shaking; 5.Extending the study from 2D to 3D. Selected sites will be used to calibrate the model. The position is open as part of the collaborative research project SLIDE: Assessing the contribution of slow moving landslides to erosion in the Himalayas, funded by the French National Research Agency (ANR) for 4 years. The SLIDE project has started in November 2024 and involves 20 researchers from 3 research institutes (CRPG, ISTerre, ECGS in Luxembourg).

The application should include a cover letter of max 2 pages, shortly describing the candidate's personal motivation for applying to this postdoctoral position and how she/he sees her/his role in contributing to the project, as well as her/his relevant skills, qualifications and research interests. The application should also include a CV (with a full publication list), PhD degree certificate, PhD thesis, and other relevant documents, as well as the contact details of 2-3 referees. The application should be sent to Dr Luc Scholtès (luc.scholtes@uca.fr) and Dr Jérôme Lavé ( jerome.lave@ univ-lorraine.fr ).