eCite Digital Repository

Ice flow modulated by tides at up to annual periods at Rutford Ice Stream, West Antarctica


Murray, T and Smith, AM and King, MA and Weedon, GP, Ice flow modulated by tides at up to annual periods at Rutford Ice Stream, West Antarctica, Geophysical Research Letters, 34, (18) ISSN 0094-8276 (2007) [Refereed Article]

DOI: doi:10.1029/2007GL031207


For over 2-years we have collected GPS data ∼40 km upstream of the grounding line on Rutford Ice Stream, West Antarctica. Here we examine deviations from mean downstream flow. Although the record is incomplete during winter, there is clear modulation of flow at semi-diurnal, diurnal, two-weekly, semi-annual, and annual ocean tidal frequencies. This is the first observation of ice stream flow variations over such a long time-period, and such a wide range of frequencies. The ice stream flows fastest at equinoxes when there are two semi-diurnal tides of equal magnitude, and slowest at solstices when one of the semi-diurnal tides has lower amplitude. The sensitivity of the downstream flow is greatest to the long-period forcing, which suggests that ice stream velocity may be affected by future changes in sea level. If so, this effect would provide a feedback whereby rising sea levels could increase ice stream velocity and hence discharge. Copyright 2007 by the American Geophysical Union.

Item Details

Item Type:Refereed Article
Keywords:Global positioning system; Natural frequencies; Sea level; Tides; Water waves; Ice stream flow; Ocean tidal frequency; Oceanography; ice flow; ice stream; ocean tide; sea level; Antarctica; 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
UTAS Author:King, MA (Professor Matt King)
ID Code:81944
Year Published:2007
Web of Science® Times Cited:42
Deposited By:Geography and Environmental Studies
Deposited On:2013-01-11
Last Modified:2013-01-11

Repository Staff Only: item control page