Tidal modulation of ice shelf buttressing stresses

Ocean tides influence the flow of marine-terminating glaciers. Observations indicate that the large fortnightly variations in ice flow at Rutford Ice Stream in West Antarctica originate in the floating ice shelf. We show that nonlinear variations in ice shelf buttressing driven by tides can produce...

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Bibliographic Details
Published in:Annals of Glaciology
Main Authors: Robel, Alexander A., Tsai, Victor C., Minchew, Brent, Simons, Mark
Format: Article in Journal/Newspaper
Language:English
Published: Cambridge University Press 2017
Subjects:
Online Access:https://authors.library.caltech.edu/83985/
https://authors.library.caltech.edu/83985/1/tidal_modulation_of_ice_shelf_buttressing_stresses.pdf
https://resolver.caltech.edu/CaltechAUTHORS:20171220-130521553
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Summary:Ocean tides influence the flow of marine-terminating glaciers. Observations indicate that the large fortnightly variations in ice flow at Rutford Ice Stream in West Antarctica originate in the floating ice shelf. We show that nonlinear variations in ice shelf buttressing driven by tides can produce such fortnightly variations in ice flow. These nonlinearities in the tidal modulation of buttressing stresses can be caused by asymmetries in the contact stress from migration of the grounding line and bathymetric pinning points beneath the ice shelf. Using a simple viscoelastic model, we demonstrate that a combination of buttressing and hydrostatic stress variations can explain a diverse range of tidal variations in ice shelf flow, including the period, phase and amplitude of flow variations observed at Rutford and Bindschadler Ice Streams.