Rosier, Sebastian, Gudmundsson, Hilmar, King, Matt, Nicholls, Keith, Makinson, Keith and Corr, Hugh (2017) Strong tidal variations in ice flow observed across the entire Ronne Ice Shelf and adjoining ice streams. Earth System Science Data, 9 (2). pp. 849-860. ISSN 1866-3508
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Rosier et al - Strong tidal variations in ice flow observed across the entire Ronne Ice Shelf and adjoining ice streams OA.pdf - Published Version Available under License Creative Commons Attribution 4.0. Download (7MB) | Preview |
Abstract
We present a compilation of GPS time series, including those for previously unpublished sites, showing that flow across the entire Ronne Ice Shelf and its adjoining ice streams is strongly affected by ocean tides. Previous observations have shown strong horizontal diurnal and semidiurnal motion of the ice shelf, and surface flow speeds of Rutford Ice Stream (RIS) are known to vary with a fortnightly (Msf) periodicity. Our new data set shows that the Msf flow modulation, first observed on RIS, is also found on Evans, Talutis, Institute, and Foundation ice streams, i.e. on all ice streams for which data are available. The amplitude of the Msf signal increases downstream of grounding lines, reaching up to 20 % of mean flow speeds where ice streams feed into the main ice shelf. Upstream of ice stream grounding lines, decay length scales are relatively uniform for all ice streams but the speed at which the Msf signal propagates upstream shows more variation. Observations and modelling of tidal variations in ice flow can help constrain crucial parameters that determine the rate and extent of potential ice mass loss from Antarctica. Given that the Msf modulation in ice flow is readily observed across the entire region at distances of up to 80 km upstream of grounding lines, but is not completely reproduced in any existing numerical model, this new data set suggests a pressing need to identify the missing processes responsible for its generation and propagation. The new GPS data set is publicly available through the UK Polar Data Centre at http://doi.org/10.5285/4fe11286-0e53-4a03-854c-a79a44d1e356.
| Item Type: | Article |
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| Additional Information: | Funding information: Sebastian H. R. Rosier was funded by the UK Natural Environment Research Council large grant “Ice shelves in a warming world: Filchner Ice Shelf System” (NE/L013770/1). The work was also partly supported by a NERC Geophysical Equipment Facility loan (NERC grant NE/D009960/1), an Australian Research Council Future Fellowship (project number FT110100207) and the Australian Research Council Special Research Initiative for Antarctic Gateway Partnership (project ID SR140300001). We are very grateful to BAS logistics, pilots, and field assistants for their tireless work to help acquire the data and we are grateful to Brent Minchew for his help in producing some of the figures. We also thank the reviewers (Laurie Padman and Ryan Walker) and editor (Reinhard Drews) for their helpful comments on the paper. |
| Subjects: | F800 Physical and Terrestrial Geographical and Environmental Sciences |
| Department: | Faculties > Engineering and Environment > Geography and Environmental Sciences |
| Depositing User: | Paul Burns |
| Date Deposited: | 15 Jun 2018 11:02 |
| Last Modified: | 16 May 2022 14:30 |
| URI: | http://nrl.northumbria.ac.uk/id/eprint/34564 |
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