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Detecting Subtle Deformation on Tropical Volcanic Islands: Advanced InSAR Time Series Techniques for Enhanced Monitoring

Smittarello D 1., d'Oreye N1,2., Derauw D3., Froger J-L4. Cayol V5., Hautecoeur A5.

  • Affiliations: 1 European Center for Geodynamics and Seismology, 19 Rue Jose Welter, l-7256 Walferdange, Luxembourg 2 National Museum of Natural History Dept. Geophysics/Astrophysics, 19 Rue Jose Welter, l-7256 Walferdange, Luxembourg 3 Centre Spatial de Liège, Avenue du Pré Aily, 4031 Angleur, Belgium 4 Université Jean Monnet - Faculté des Sciences et Techniques, Laboratoire de Géologie de Lyon:Terre, Planètes, Environnement. UMR CNRS 5276, France 5 Laboratoire Magmas et Volcans, Université Clermont Auvergne, CNRS, IRD, OPGC, Clermont-Ferrand, France

  • Presentation type: Poster

  • Presentation time: Monday 16:30 - 18:30, Room Poster Hall

  • Poster Board Number: 131

  • Programme No: 3.1.23

  • Theme 3 > Session 1

Abstract

Tropical volcanic islands are often densely vegetated and feature steep, rugged terrains, which can complicate InSAR analysis as they are prone to coherence loss and atmospheric artifacts. Despite these challenges, AMSTer software (a fully automatized, incremental, multi-sensor InSAR processor) provides an effective solution for detecting subtle deformation in such environments by integrating multi-sensor data and offering high-resolution, long-term monitoring capabilities. We processed InSAR time series with AMSTer over three volcanic targets: Soufrière de Guadeloupe, Karthala (Comoros), and Piton de la Fournaise (Réunion Island). - Soufrière de Guadeloupe: Using Sentinel-1 (S1) data from 2018 to 2024, we detected linear summit inflation and significant south flank sliding, revealing subtle deformation dynamics on this stratovolcano. - Karthala: By combining S1 and COSMO-SkyMed (CSK) data, and applying Singular Value Decomposition (SVD) to remove seasonal artifacts, we observed deformation linked to a low overpressure dike intrusion in mid-2022. Despite significant crustal movement, the intrusion failed to trigger an eruption, providing insight into the complex volcanic processes in this region. - Piton de la Fournaise: Using ALOS-2 data, we tracked subtle inter-eruptive deformation in 3D, to capture the dynamics of the deeper magma reservoir between eruptions, with implications for eruption forecasting and hazard assessment. AMSTer's ability to process data from multiple satellite platforms (including Sentinel-1, CSK, ALOS-2, and others), along with its fully automated and incremental processing, makes it a powerful tool for overcoming the challenges of monitoring deformation on tropical volcanic islands.