| Title | Terrain controls on the occurrence of coastal retrogressive thaw slumps along the Yukon Coast, Canada |
| Author | Ramage, J L; Irrgang, A M; Herzchuh, U; Morgenstern, A; Couture, N; Lantuit, H |
| Source | Journal of Geophysical Research, Earth Surface vol. 122, 2017., https://doi.org/10.1002/2017JF004231 |
| Year | 2017 |
| Alt Series | Natural Resources Canada, Contribution Series 20170021 |
| Publisher | Wiley-Blackwell |
| Document | serial |
| Lang. | English |
| Media | paper; on-line; digital |
| File format | pdf |
| Province | Yukon; Northern offshore region |
| NTS | 117D; 117C/01; 117C/08; 117C/09; 117C/16 |
| Area | Herschel Island; Yukon Coast; Beaufort Sea |
| Lat/Long WENS | -141.0000 -137.0000 69.6667 69.0000 |
| Subjects | Nature and Environment; slumps; permafrost; ground ice; ice conditions; ice disintegration features; coastal environment; coastal studies; coastal erosion; coastal management; slope stability; slope
failures; univariate regression trees model; global carbon budget |
| Illustrations | location maps; tables; satellite images; plots; schematic diagrams |
| Program | Climate Change
Geoscience, Coastal Infrastructure |
| Released | 2017 09 08 |
| Abstract | Retrogressive thaw slumps (RTSs) are among the most active landforms in the Arctic; their number has increased significantly over the past decades. While processes initiating discrete RTSs are well
identified, the major terrain controls on the development of coastal RTSs at a regional scale are not yet defined. Our research reveals the main geomorphic factors that determine the development of RTSs along a 238 km segment of the Yukon Coast,
Canada. We (1) show the current extent of RTSs, (2) ascertain the factors controlling their activity and initiation, and (3) explain the spatial differences in the density and areal coverage of RTSs. We mapped and classified 287 RTSs using
high-resolution satellite images acquired in 2011. We highlighted the main terrain controls over their development using univariate regression trees model. Coastal geomorphology influenced both the activity and initiation of RTSs: active RTSs and
RTSs initiated after 1972 occurred primarily on terrains with slope angles greater than 3.9° and 5.9°, respectively. The density and areal coverage of RTSs were constrained by the volume and thickness of massive ice bodies. Differences in rates of
coastal change along the coast did not affect the model. We infer that rates of coastal change averaged over a 39 year period are unable to reflect the complex relationship between RTSs and coastline dynamics. We emphasize the need for large-scale
studies of RTSs to evaluate their impact on the ecosystem and to measure their contribution to the global carbon budget. |
| Summary | (Plain Language Summary, not published)
Retrogressive thaw slumps (RTSs) are landforms in the Arctic caused by thawing ground ice. This research examines a 235 km coastal segment of the Yukon
Coastal Plain, Canada, to see how geomorphology controls the development of RTSs. We mapped and classified the RTSs using satellite images from 2011 and then used statistical analyses to determine the main geomorphic controls. The results show that
slope angle affected both the initiation and the level of activity of the slumps, while the presence of massive ground ice within permafrost affected the number and extent of them. Coastal erosion appears to affect them only indirectly by
maintaining good conditions for reactivation. |
| GEOSCAN ID | 300542 |
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