| Title | Characterizing interannual variability of glacier dynamics and dynamic discharge (1999–2015) for the ice masses of Ellesmere and Axel Heiberg Islands, Nunavut, Canada |
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| Author | Van Wychen, W; Davis, J; Burgess, D O ; Copland, L; Gray, L; Sharp, M; Dowdeswell, J |
| Source | Journal of Geophysical Research, Earth Surface vol. 121, issue 1, 2016 p. 39-63, https://doi.org/10.1002/2015jf003708 |
| Image |  |
| Year | 2016 |
| Alt Series | Earth Sciences Sector, Contribution Series 20150295 |
| Publisher | Wiley-Blackwell |
| Document | serial |
| Lang. | English |
| Media | paper; on-line; digital |
| File format | pdf |
| Province | Nunavut |
| NTS | 120B; 120C; 120D; 120F; 120E; 120G; 340; 39; 49; 59F; 59G; 59H; 59E; 560A; 560B; 560D |
| Area | Axel Heiberg Island; Ellesmere Island |
| Lat/Long WENS | -98.0000 -80.0000 82.0000 76.0000 |
| Subjects | Nature and Environment; remote sensing; LANDSAT imagery; glacier surveys; glaciers; glacial surges; ice flow; discharge rates; RADARSAT-1; RADARSAT-2; Trinity glacier; Wykeham glacier |
| Illustrations | satellite images; location maps; tables; graphs |
| Program | Climate Change Geoscience Essential Climate Variable Monitoring |
| Released | 2016 01 14 |
| Abstract | Landsat 7 and RADARSAT-1/RADARSAT-2 satellite images are used to produce the most comprehensive record of glacier motion in the Canadian High Arctic to date and to characterize spatial and temporal
variability in ice flow over the past ~15 years. This allows us to assess whether dynamically driven glacier change can be attributed to "surging" or "pulsing," or whether other mechanisms are involved. RADAR velocity mapping allows annual regional
dynamic discharge (iceberg calving) to be calculated for 2000 and the period 2011-2015 (yielding a mean regional discharge of 2.21±0.68 Gt a-1), and velocities derived from feature tracking of optical imagery allow for annual dynamic discharge to be
calculated for select glaciers from 1999 to 2010. Since ~2011, several of the major tidewater-terminating glaciers within the region have decelerated and their dynamic discharge has decreased. Trinity and Wykeham Glaciers (Prince of Wales Icefield)
represent a notable departure from this pattern as they have generally accelerated over the study period. The resulting increase in dynamic discharge from these glaciers entirely compensates (within error limits) for the decrease in discharge from
the other tidewater glaciers across the study region. These two glaciers accounted for ~62% of total regional dynamic discharge in winter 2015 (compared to ~22% in 2000), demonstrating that total ice discharge from the Canadian High Arctic can be
sensitive to variations in flow of just a few tidewater glaciers. |
| Summary | (Plain Language Summary, not published)
Glacier mass loss due to ice-berg calving is an important form of ablation from ice caps in the Canadian high Arctic being second only to mass loss due
to summer melting. Until recently however, the rate of calving flux from this region has been poorly quantified. This paper provides the most complete estimate calving flux to date from ice velocity fields derived using RADARSAT-2 and Landsat
imagery, along with all available ice thickness data to date. Results from this study indicate that Canadian ice caps lost ~2.2 Gigatons per year over the past 15 years. Results indicate that total ice discharge from the Canadian High Arctic is very
sensitive to variations in flow of just a few individual calving glaciers. |
| GEOSCAN ID | 297299 |
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