Abstract

The Altiplano region in the Central Andes is a natural laboratory for studying tectonic and geomorphological processes in continental highlands. Its active deformation and flexural rigidity are key to understanding crustal dynamics in a subduction context and the long-term evolution of Andean landscapes. Yet, the mechanisms driving this deformation and the spatial–temporal variations in fault activity or lithospheric rigidity remain poorly constrained. This PhD will address these questions by combining innovative approaches: Holocene geomorphology analysis on Pléiades DEM with ScarpLearn (Deep Learning), interpretation of continental-scale FLATSIM InSAR data, and the integration of nested spatial and temporal scales thanks to TCN dating of morainic markers (~4500m high).

Objectives

1. Characterize active deformation of the Altiplano plateau through Holocene geomor-phological markers and processes, identifying fault scarps and quantifying deformation rates. Previous TCN dating of glacial moraines (Parina fault; Aguirre, Audin et al., 2021) provides a foundation for constraining recent deformation. New analyses will refine de-formation rates across faults affecting Holocene moraines (11–15 ka rather than 45 ka, Cuscco fault; Rosell et al., 2023).

2. Combine InSAR FLATSIM and ScarpLearn data with Pléiades DEMs to quantify pre-sent-day surface deformation with unprecedented precision and compare it with Holo-cene rates in southern Peru (Lovery et al., 2024; Marconato et al., 2024).

3. Evaluate lithospheric flexural rigidity (effective elastic thickness Tₑ) and integrate mul-ti-scale analyses to understand how local and regional processes interact to control pla-teau deformation. Continental-scale InSAR analysis will help constrain superficial exten-sion and reveal spatial variability of lithospheric rigidity across the Central Andes (Pé-rez-Gussinyé et al., 2007, 2008; Tassara 2007; Watts 2003; Garcia et al., 2018).

Perspectives and Scientific Relevance for CNES:

This PhD sits at the crossroads of space geodesy, geomorphology, and lithospheric geophysics, fully aligned with CNES priorities in Earth observation and geodynamic monitoring. By coupling continental InSAR fields from FLATSIM with Pléiades optical and DEM data, the project will ge-nerate new constraints on crustal coupling, lithospheric strength, and surface deformation me-chanisms. It will highlight the potential of satellite geodesy and optical imagery for understan-ding lithospheric processes, assessing crustal hazards, and reconstructing long-term plateau evolution.

The work is embedded in IRD’s Andean cooperation framework, supported by existing MoUs and partnerships in South America (with geological services and universities in Peru, Bolivia, and Chile). These collaborations ensure access to validated datasets, shared instrumentation, and co-supervision of students, reinforcing the project’s cooperative and capacity-building di-mension.

For CNES, the project showcases the scientific value of French missions—Pléiades, Sentinel-1, and future SWOT and NISAR—for monitoring continental deformation and natural hazards. The results will improve lithospheric models, refine hazard assessments in high-plateau environ-ments, and develop transferable methodologies applicable to other orogenic systems worldwide, thus advancing CNES’s strategic goals of fostering interdisciplinary research and en-hancing France’s international visibility in space geosciences.

Expected Deliverables and Impacts

The PhD will yield:

• High-resolution deformation maps from FLATSIM and Pléiades datasets, documenting active faulting and surface strain across the Central Andes;

• A regional model of lithospheric flexural rigidity (Tₑ) integrating InSAR, geomorphological, and gravimetric constraints for geodynamic modeling;

• An open-access geospatial database of active faults and Holocene markers (moraines, scarps, fans), interoperable with the INGEMMET fault database (Geocatmin platform);

• Peer-reviewed papers and presentations at CNES-supported and international conferences (AGU, EGU, Galileo Conference on InSAR);

• Methodological advances in combining optical and radar satellite data for deformation moni-toring, transferable to other CNES-funded regions (e.g. Mediterranean, Africa).

Host and trainings :

PhD hosted within ISTERRE and IRD in the Seismic Cycle team (Doin, Giffard, Socquet, Chlieh), in collaboration with CNES, CNRS, MIAI Cluster IA - Multidisciplinary Institute in Artificial Intelligence and the research program Risques (PEPR IRiMa). Note potential field trips under the Andean IRD cooperation framework (existing MoUs). Data sources: CNES (Pléiades), ESA (Sentinel-1), FLATSIM consortium. 

* Aguirre, Audin et al., 2021 doi: 10.1016/j.jsames.2020.103098

* Pousse-Beltran, Audin et al., 2025   DOI: https://doi.org/10.26443/seismica.v4i2.1387 ;

* Rosell,Audin et al., 2023  DOI: https://doi.org/10.55575/tektonika2023.1.2.27 ;

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For more Information about the topics and the co-financial partner (found by the lab!); contact Directeur de thèse - laurence.audin@univ-grenoble-alpes.fr

Then, prepare a resume, a recent transcript and a reference letter from your M2 supervisor/ engineering school director and you will be ready to apply online  before March 13th, 2026 Midnight Paris time!