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TitleSpatial variation of ice motion and ice flux from Devon Ice Cap, Nunavut, Canada
AuthorVan Wychen, W; Copland, L; Gray, L; Burgess, D; Danielson, B; Sharp, M
SourceJournal of Glaciology vol. 58, no. 210, 2012 p. 657-664,
Alt SeriesEarth Sciences Sector, Contribution Series 20150329
PublisherInternational Glaciological Society
Mediapaper; on-line; digital
File formatpdf
AreaDevon Ice Cap; Devon Island
Lat/Long WENS -84.0000 -80.0000 76.0000 75.0000
Subjectssurficial geology/geomorphology; geophysics; remote sensing; satellite imagery; ice; ice movement; RADARSAT-2; Cenozoic; Quaternary
Illustrationshistograms; plots; satellite images
ProgramEarth Science for National Scale Characterization of Climate Change Impacts on Canada's Landmass, Climate Change Geoscience
AbstractSpeckle tracking of repeat RADARSAT-2 fine-beam imagery acquired over 24 day periods in March 2009 allowed the creation of updated surface motion maps for the entire Devon Ice Cap, Canada. Error analysis indicates that speckle tracking can determine ice motion to an accuracy of ~5 ma -1. Comparisons with earlier velocity maps from the mid-1990s and 2000 reveal velocity patterns that largely agree with flow regimes described previously. However, motion determined along East5 Glacier indicates an increase in surface velocities between the studies. Additionally, Southeast2 Glacier has significantly accelerated over the past decade, with velocities greater in 2009 than in the early 1990s along almost the entire length of the glacier. This is likely indicative of a surge. Present-day total mass loss from Devon Ice Cap due to iceberg calving is calculated as 0.40 ± 0.09 Gt a -1, similar to that reported by Burgess and others (2005), with Belcher Glacier accounting for ~42% of the entire loss.
Summary(Plain Language Summary, not published)
The large (> 5000 km2) ice caps in the Canadian high Arctic are drained by outlet glaciers many of which are tidewater terminating. These glaciers flow at speeds 1 - 2 orders of magnitude faster than the interior stagnant ice and represent important conduits for the transfer of mass from the high elevation regions directly to oceans. Variations in velocity of these glaciers has a direct and immediate impact on ice cap geometry and rate of ice discharge to oceans. This paper provides a recent (2009) map of glacier velocities for one of the largest ice caps in the Canadian high Arctic (Devon ice cap -14,000 km2) and compares these with earlier (1992/1993) published values. Results show that while some of the interior ice flow along outlet glaciers has increased in speed over the 17 year period, the rate of ice discharged directly to oceans has not changed significantly.