Strain-rate evolution in the European Alps due to Glacial Isostatic Adjustment since the Last Glacial Maximum

Current vertical movements in the Alpine region are the result of several interacting processes operating simultaneously. Among these, Glacial Isostatic Adjustment (GIA) plays a key role as a long-term global process driven by interactions between the cryosphere, solid Earth, and oceans in response to the melting of continental ice sheets. Although the effects of GIA in the Alpine region have been the subject of numerous studies, considerable uncertainties remain, in particular regarding the extent and chronology of the Würm Alpine Ice Sheet and the rheological properties of the mantle. In this study, we take advantage of recently updated deglaciation chronologies for Late-Pleistocene ice sheets to refine estimates of GIA-induced crustal deformation. We model postglacial rebound using the open-source TABOO code in combination with a high-resolution Alpine ice model, incorporating a mini-ensemble approach to account for uncertainties in the rheological model. We also calculate the deformation components in the study area using the VISR code, allowing a detailed assessment of the evolution of the deformation rate. Our modelling shows that GIA-related strain rates reached a maximum of 7.8 nstrain yr −1 at 25 kyr BP and progressively decreased throughout the Holocene, approaching present-day values of only 0.25 nstrain yr −1 . This long-term decay indicates that the Alpine GIA signal is now largely exhausted, leaving only a weak residual contribution to the modern deformation field. The combined use of the TABOO code, the Alpine ice model, and the VISR code allows us to robustly quantify the evolution of the GIA-driven deformation rates and improve our understanding of post-glacial crustal dynamics and provide new constraints for future geodynamic models in the Alpine region.