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Lookup NU author(s): Dr Achraf Koulali IdrissiORCiD, Professor Peter ClarkeORCiD
This work is licensed under a Creative Commons Attribution 4.0 International License (CC BY 4.0).
© 2025. The Author(s).Present-day ice-mass changes in Antarctica typically deform the solid Earth elastically, and this signal needs removing from Global Positioning System (GPS) observations of displacement before they can be used to constrain models of glacial isostatic adjustment. However, much of West Antarctica is underlain by weak upper mantle, meaning these short-term fluctuations may also cause viscous (transient or steady-state) deformation of the Earth. We model the viscoelastic response of the Earth to surface mass balance (SMB) variability in the Antarctic Peninsula and find an improved fit to GPS data at most sites compared to elastic only. Viscoelastic modeling constrains upper mantle steady-state viscosity in the northern Peninsula to 5 × 1017 to 2 × 1018 Pa s, and >1 × 1018 Pa s for the mid to southern Peninsula. In the northern Peninsula, removing viscoelastic displacement caused by SMB variability from GPS time series increases estimated uplift rates by up to 3 mm/yr compared with using an elastic-only correction.
Author(s): Nield GA, Bentley MJ, Koulali A, Clarke PJ, King MA, Wilson T, Whitehouse PL
Publication type: Article
Publication status: Published
Journal: Geophysical Research Letters
Year: 2025
Volume: 52
Issue: 12
Print publication date: 28/06/2025
Online publication date: 19/06/2025
Acceptance date: 23/05/2025
Date deposited: 30/07/2025
ISSN (print): 0094-8276
ISSN (electronic): 1944-8007
Publisher: John Wiley and Sons Inc
URL: https://doi.org/10.1029/2025GL114595
DOI: 10.1029/2025GL114595
Data Access Statement: Table S1 in Supporting Information S1 contains a table of GPS site metadata sources. UKANET data is available at Whitehouse and Clarke (2024). Modeling was performed using Abaqus—a commercial software and can be purchased from the developer (Dassault Systemes, 2023). We have used version 2023 in this study. Outputs for the best fitting model and corrected GPS time series are archived on Zenodo (Nield, 2025), and will be available at the NERC Polar Data Centre repository. Figures have been produced using Generic Mapping Tools (Wessel et al., 2013).
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