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Nonlinear interaction between ocean tides and the Larsen C Ice Shelf system


King, MA and Makinson, K and Gudmundsson, GH, Nonlinear interaction between ocean tides and the Larsen C Ice Shelf system, Geophysical Research Letters, 38, (8) Article L08501. ISSN 0094-8276 (2011) [Refereed Article]

DOI: doi:10.1029/2011GL046680


We report on three GPS records of flow of the Larsen C Ice Shelf, spanning 2 months to 2 years. Variations in speed are evident at periods from a few hours to ∼182 days, including semi-diurnal, diurnal and ∼14.76 days. At fortnightly periods the ice shelf varies by 10% from its long-term speed but at diurnal timescales it is up to 100%. A nonlinear relationship between ocean tides and velocity is required to explain the observed variations in flow. As an initial examination we model flow as a non-linear function of basal shear stress including tidal perturbations in the ice shelf grounding zone and show that the major features of the observations are reproduced, notably the long-period signal largely absent from the vertical tidal signal. Alternative explanations are discussed. These observations demonstrate that the ice shelf system is highly sensitive to relatively modest changes in forcing at its boundaries. Copyright 2011 by the American Geophysical Union.

Item Details

Item Type:Refereed Article
Keywords:Highly sensitive; Ice shelves; Non-linear relationships; Nonlinear functions; Nonlinear interactions; Ocean tides; Semi-diurnal; Tidal perturbations; Tidal signals; Time-scales; Functions; Shear flow; Tides; Ice; flow velocity; GPS; ice field
Research Division:Earth Sciences
Research Group:Physical geography and environmental geoscience
Research Field:Physical geography and environmental geoscience not elsewhere classified
Objective Division:Expanding Knowledge
Objective Group:Expanding knowledge
Objective Field:Expanding knowledge in the earth sciences
UTAS Author:King, MA (Professor Matt King)
ID Code:82167
Year Published:2011
Web of Science® Times Cited:10
Deposited By:Geography and Environmental Studies
Deposited On:2013-01-17
Last Modified:2017-11-01

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