Folding due to anisotropy in ice, from drill-core-scale cloudy bands to km-scale internal reflection horizons
Abstract. Upright folds in ice sheets are observed on the cm scale in cloudy bands in drill cores and on the km scale in radargrams. We address the question of the folding mechanism for these folds by analysing the power spectra of fold trains to obtain the amplitude as a function of wavelength signal. Classical Biot-type buckle folds due to a rheological contrast between layers develop a characteristic wavelength, visible as a peak in the power spectrum. Power spectra of ice folds, however, follow a power law, with a steady increase in amplitude with wavelength. Such a power spectrum is also observed in a folded, highly anisotropic biotite schist and in a numerical simulation of the deformation of ice Ih with a strong alignment of the basal planes parallel to the shortening direction. This suggests that the folds observed in ice are primarily due to the strong mechanical anisotropy of ice, which tends to have a strong lattice preferred orientation due to ice-sheet flow.
Authors
- Julien Westhoff (ORCID: https://orcid.org/0000-0001-7818-1786)
- Nicolas Stoll (ORCID: https://orcid.org/0000-0002-3219-8395)
- Yu Zhang (ORCID: https://orcid.org/0000-0002-6948-0730)
- Yuanbang Hu (ORCID: https://orcid.org/0000-0002-8709-1165)
- Paul D. Bons (ORCID: https://orcid.org/0000-0002-6469-3526)
- María-Gema Llorens (ORCID: https://orcid.org/0000-0002-6148-2600)
- Steven Franke (ORCID: https://orcid.org/0000-0001-8462-4379)
- Ilka Weikusat (ORCID: https://orcid.org/0000-0002-3023-6036)
Institutions
- University of Copenhagen (DK)
- Alfred-Wegener-Institut Helmholtz-Zentrum für Polar- und Meeresforschung (DE)
- Ca' Foscari University of Venice (IT)
- China University of Geosciences (Beijing) (CN)
- Grupo Español de Cáncer de Pulmón (ES)
- Center for High Pressure Science and Technology Advanced Research (CN)
- Center for High Pressure Science & Technology Advanced Research (CN)
- University of Tübingen (DE)
Publication Details
- Journal
- The cryosphere
- Published
- 2025-10-27
- DOI
- https://doi.org/10.5194/tc-19-5095-2025
- Primary Topic
- Cryospheric studies and observations
- Type
- article
- Field-Weighted Citation Impact
- 0.00
Funders
- National Science Foundation
- National Aeronautics and Space Administration
- Trond Mohn stiftelse
- European Commission
- Deutscher Akademischer Austauschdienst
- Deutsche Forschungsgemeinschaft
- Chinese Academy of Sciences
- Beijing Normal University
- Nuclear Safety and Security Commission
- China Scholarship Council
- Institut Polaire Français Paul Emile Victor
- Universitetet i Bergen
- A.P. Møller og Hustru Chastine Mc-Kinney Møllers Fond til almene Formaal
- National Institute of Polar Research
- Office of Polar Programs