| Title | Recent ponding of upland ice-wedge polygon networks detected across the Canadian Arctic Archipelago using satellite remote sensing |
| Download | Downloads |
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| Licence | Please note the adoption of the Open Government Licence - Canada
supersedes any previous licences. |
| Author | Fraser, R H ;
McFarlane-Winchester, M; Kokelj, S V |
| Source | Geomatics Canada, Open File 69, 2023, 28 pages, https://doi.org/10.4095/329618  Open Access |
| Image |  |
| Year | 2023 |
| Publisher | Natural Resources Canada |
| Document | open file |
| Lang. | English |
| Media | digital; on-line |
| Related | This publication accompanies Climate sensitivity of high
arctic permafrost terrain demonstrated by widespread ice-wedge thermokarst on Banks Island |
| File format | pdf |
| Province | Northwest Territories; Nunavut; Yukon |
| NTS | 46M; 47B; 47C; 47F; 47G; 48B; 48C; 49M; 49P; 57; 58; 66M; 66N; 66O; 66P; 67; 68; 69; 76M; 76N; 76O; 76P; 77; 78; 79; 86; 87; 88; 89; 97; 98; 99; 107; 117 |
| Area | Tuktoyaktuk; Banks Island; Victoria Island; Prince of Wales Island; Somerset Island; Boothia Peninsula; Brodeur Peninsula; Melville Island; Prince Patrick Island; Ellef Ringnes Island; Beaufort Sea;
Amundsen Gulf; Simpson Peninsula; Cornwallis Island; Dolphin and Union Strait; Coronation Gulf; Queen Maud Gulf |
| Lat/Long WENS | -141.0000 -70.0000 78.0000 67.0000 |
| Subjects | surficial geology/geomorphology; environmental geology; geophysics; permafrost; ground ice; periglacial features; thermokarst; climate effects; temperature; ice-wedge polygons; remote sensing; satellite
imagery; subsidence; hummocks; mapping techniques; Canadian Arctic Archipelago; Beaufort Coastlands; Yukon Coastal Plain; Tuktoyaktuk Coastlands; Landsat; permafrost thaw |
| Illustrations | photographs; location maps; satellite images; tables; geoscientific sketch maps; bar graphs |
| Program | Canada Centre for Remote Sensing Remote Sensing Science Program - Management |
| Released | 2023 04 11 |
| Abstract | (Summary)
Recent studies have demonstrated the sensitivity of cold, high-Arctic permafrost to rapid thaw. In Fraser et al. (2018), we showed that a series of anomalously warm summers in 1998
and 2010-2012 caused widespread, top-down thawing of hilltop ice-wedge networks across Banks Island (70 028 km2) in the Canadian Arctic Archipelago. Several remote sensing datasets were used to identify numerous new ponds resulting from the melting
of ice wedges and subsequent ground subsidence, or thermokarst. This Geomatics Canada Open File serves as a supplement to Fraser et al. (2018) by using similar, multi-scale remote sensing data to investigate the occurrence of upland ice-wedge
thermokarst across a much larger 396 000 km2 study domain in the Arctic Archipelago and Beaufort Coastlands. We show that ponded ice-wedge networks are common in semi-barren uplands and that, in 85% of visible ice-wedge polygon networks larger than
25 ha, a > 75% increase in ponding can be detected since the beginning of the 30 m Landsat satellite record in 1984. Large, upland ice-wedge melt ponds are frequently associated with ice-rich hummocky terrain, and they are generally less common and
smaller in the warmer, ice-rich permafrost within the Yukon Coastal Plain and Tuktoyaktuk Coastlands. Similar to Banks Island, climate records from the expanded study domain suggest that warming temperatures are the primary driver of thermokarst.
Records indicate an average annual 2.8 C temperature increase over 52-74 years and that the 2010-2012 summers were 2.2 C warmer than average. |
| Summary | (Plain Language Summary, not published)
Permanently frozen ground (called permafrost) has recently started thawing in many regions of the high-Arctic due to recent warm summers. This thawing
can melt large ice wedges in the ground that have been slowly growing for hundreds or thousands of years. The melting and removal of this ground ice causes the ground to subside in a process called thermokarst, resulting in the formation of small
melt ponds in relatively flat areas. In this study we mapped the occurrence of new thermokarst melt ponds over a 396 000 km2 region within Canada's Arctic Archipelago and Beaufort Coastlands. We used satellite imagery and historical air photos to
show that newly formed melt ponds caused by ice-wedge thermokarst are common over this region, especially in formerly glaciated areas containing significant concentrations of ground ice. These changes were most likely caused by recent summers that
were more than 2 °C warmer than average. |
| GEOSCAN ID | 329618 |
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