Spatial Heterogeneity of Uplift Pattern in the Western European Alps Revealed by InSAR Time‐Series Analysis

M. Mathey (1) , P. André (2) , A. Walpersdorf (1) , S. Baize (3) , C. Sue (1)

1 ISTerre - Institut des Sciences de la Terre
2 AIM (UMR_7158 / UMR_E_9005 / UM_112) - Astrophysique Interprétation Modélisation
3 IRSN/PSE-ENV/SCAN/BERSSIN - Bureau d'évaluation des risques sismiques pour la sûreté des installations

The Western European Alps display measurable surface deformation rates from leveling and GNSS data. Based on the time-series analysis of 4 years of Sentinel-1 data, we propose for the first time an InSAR-based mapping of the uplift pattern affecting the Western Alps on a ∼350 × 175-km-wide area. This approach provides a denser spatial distribution of vertical motion despite the high noise level inherent to mountainous areas and the low expected deformation signal. Our results show consistency with other geodetic measurements at the regional scale, and reveal smaller-scale spatial variations in the uplift pattern. Higher uplift rates are found within the external crystalline massifs compared to surrounding areas, in agreement with the variations expected from recent deglaciation and long-term exhumation data. This work brings the first InSAR-based geodetic clue of differential uplift within the Alpine belt in response to the surface and deep processes affecting the belt.

Domaines: Planète et Univers [physics]

M. Mathey, P. André, A. Walpersdorf, S. Baize, C. Sue. Spatial Heterogeneity of Uplift Pattern in the Western European Alps Revealed by InSAR Time‐Series Analysis. Geophysical Research Letters, 2022, 49 (1), ⟨10.1029/2021GL095744⟩. ⟨irsn-03977110⟩