| Title | Variability in ice motion and dynamic discharge from Devon Ice Cap, Nunavut, Canada |
| |
| Author | Van Wychen, W; Davis, J; Copland, L; Burgess, D O ; Gray, L; Sharp, M; Dowdeswell, J A; Benham, T J |
| Source | Journal of Glaciology vol. 63, issue 239, 2017 p. 436-449, https://doi.org/10.1017/jog.2017.2  Open Access |
| Image |  |
| Year | 2017 |
| Alt Series | Earth Sciences Sector, Contribution Series 20150442 |
| Publisher | Cambridge University Press (CUP) |
| Document | serial |
| Lang. | English |
| Media | paper; on-line; digital |
| File format | pdf |
| Province | Nunavut |
| NTS | 38F/13; 48E; 48F/09; 48F/16; 48G/01; 48G/08; 48G/09; 48G/16; 48H |
| Area | Devon Ice Cap; Devon Island; Canadian Arctic Archipelago |
| Lat/Long WENS | -85.0000 -79.5000 76.0000 74.5000 |
| Subjects | surficial geology/geomorphology; geophysics; environmental geology; Nature and Environment; glaciology; glaciers; ice movement; ice flow; displacement; ice margins; remote sensing; satellite imagery;
coastal environment; ice thickness; climate; temperature; flow regimes; mapping techniques; Ice caps; Climate change; Classification |
| Illustrations | location maps; geoscientific sketch maps; tables; graphs; time series; profiles |
| Program | Climate Change Geoscience Essential Climate Variable Monitoring |
| Released | 2017 02 07 |
| Abstract | Feature tracking of approximately annually separated Landsat-7 ETM+ imagery acquired from 1999 to 2010 and speckle tracking of 24-day separated RADARSAT-2 imagery acquired from 2009 to 2015 reveal that
motion of the major tidewater glaciers of Devon Ice Cap is more variable than previously described. The flow of almost half (six of 14) of the outlet glaciers slowed over the observation period, while that of the terminus regions of three of 14 of
the glaciers sped up in the most recent years of observation. The North Croker Bay Glacier of southern Devon Ice Cap showed the greatest variability in motion, oscillating between multi-year (three or more) periods of slower and faster flow and
exhibited a pattern of velocity variability that is different from that of the rest of the ice cap's outlet glaciers. Comparisons between areas of dynamic variability and glacier bed topography indicate that velocity variability is largely restricted
to regions where the glacier bed is grounded below sea level. Derived velocities are combined with measurements of ice thickness at the fronts of tidewater glacier to determine a mean annual (2009; 2011-15) dynamic ice discharge of 0.41 ± 0.11 Gt/a
for Devon Ice Cap. The Belcher Glacier is becoming a larger source of mass loss via ice discharge. |
| Summary | (Plain Language Summary, not published)
This study measures the variability in the rate of flow of several tidewater glaciers that drain ice caps in the Canadian high Arctic. Variations in flow
of tidewater terminating glaciers influences the volume of glacier ice transferred directly to oceans, thus impacting both total ice mass change and global sea-level. Thus, quantifying variability over a 14 year time period (ie, 2000 ¿ 2014) provides
important information on the representativeness of single velocity measurements for calculating long-term calving rates. |
| GEOSCAN ID | 295605 |
|
|