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Tidal influence on Rutford Ice Stream, West Antarctica: Observations of surface flow and basal processes from closely spaced GPS and passive seismic stations

Citation

Adalgeirsdottir, G and Smith, AM and Murray, T and King, MA and Makinson, K and Nicholls, KW and Behar, AE, Tidal influence on Rutford Ice Stream, West Antarctica: Observations of surface flow and basal processes from closely spaced GPS and passive seismic stations, Journal of Glaciology, 54, (187) pp. 715-724. ISSN 0022-1430 (2008) [Refereed Article]

DOI: doi:10.3189/002214308786570872

Abstract

High-resolution surface velocity measurements and passive seismic observations from Rutford Ice Stream, West Antarctica, 40km upstream from the grounding line are presented. These measurements indicate a complex relationship between the ocean tides and currents, basal conditions and ice-stream flow. Both the mean basal seismicity and the velocity of the ice stream are modulated by the tides. Seismic activity increases twice during each semi-diurnal tidal cycle. The tidal analysis shows the largest velocity variation is at the fortnightly period, with smaller variations superimposed at diurnal and semi-diurnal frequencies. The general pattern of the observed velocity is two velocity peaks during each semi-diurnal tidal cycle, but sometimes three peaks are observed. This pattern of two or three peaks is more regular during spring tides, when the largest-amplitude velocity variations are observed, than during neap tides. This is the first time that velocity and level of seismicity are shown to correlate and respond to tidal forcing as far as 40km upstream from the grounding line of a large ice stream.

Item Details

Item Type:Refereed Article
Keywords:basal flow; GPS; ice flow; ice stream; ice-ocean interaction; image resolution; observational method; ocean tide; oceanic current; tidal cycle; Antarctica; Rutford Ice Stream; West Antarctica
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
Author:King, MA (Professor Matt King)
ID Code:81948
Year Published:2008
Web of Science® Times Cited:13
Deposited By:Geography and Environmental Studies
Deposited On:2013-01-11
Last Modified:2013-01-11
Downloads:0

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