| Title | Long-term monitoring of permafrost temperature, active layer thickness, and surface settlement in the Mackenzie Valley, Northwest Territories |
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| Author | Duchesne, C ;
Smith, S; O'Neill, B; Chartrand, J |
| Source | Arctic Change 2020 abstracts (continued); Arctic Science vol. 7, no. 1, 2021 p. 329, https://doi.org/10.1139/as-2021-0018  Open Access |
| Image |  |
| Year | 2021 |
| Alt Series | Natural Resources Canada, Contribution Series 20200569 |
| Publisher | Canadian Science Publishing |
| Meeting | Arctic Change 2020; December 7-10, 2020 |
| Document | serial |
| Lang. | English |
| Media | paper; on-line; digital |
| File format | pdf; html |
| Province | Northwest Territories |
| NTS | 95N; 95O; 96C; 96D; 96E; 96F; 96L; 106H; 106I; 106M; 106N; 107B; 107C |
| Area | Mackenzie River; Mackenzie Delta |
| Lat/Long WENS | -136.0000 -123.0000 69.5000 63.0000 |
| Subjects | surficial geology/geomorphology; environmental geology; Nature and Environment; Science and Technology; permafrost; ground ice; ground temperatures; subsidence; climate effects; thermal analyses;
permafrost thaw; Climate change; environmental baseline studies; Land use planning |
| Program | Climate Change
Geoscience Permafrost |
| Released | 2021 06 22 |
| Abstract | A permafrost and active layer monitoring network, established in the Mackenzie Valley and Delta (Northwest Territories) by the Geological Survey of Canada, has been maintained since the 1980s. It
currently consists of 97 sites distributed in a variety of natural and undisturbed terrain conditions from the Delta to the Alberta border, where a combination of ground temperature, active layer thickness, and air and near-surface temperature data
are collected. This poster highlights permafrost temperature and active layer trends over the past 30 years. In the continuous permafrost zone, permafrost at most sites has been warming at a rate greater than 0.05 °C per year. In warmer permafrost of
the discontinuous zone, there has been less change in ground temperature, below +0.03 °C per year. Comparison of current ground temperatures to the baseline established during International Polar Year (IPY; 2007-2009), indicates that permafrost at
many sites is currently warmer than during the IPY, with smaller change where temperatures are close to 0 °C and permafrost is ice-rich due to latent heat effects. The active layer thickness, which exhibits greater inter-annual variation than deeper
ground temperature measurements, has generally increased since 2008. Analysis of long-term changes in thaw penetration and ground surface elevation for 17 sites in the Mackenzie Delta has also shown significant subsidence at more than half of the
sites due to melting of excess ground ice. Data from the permafrost monitoring network has enabled characterization of spatial and temporal variability in active layer thickness and permafrost thermal state. This unique long-term record contributes
to improved characterization of regional baseline ground thermal conditions and increased understanding of climate change impacts on the permafrost environment leading to better informed land-use planning. |
| Summary | (Plain Language Summary, not published)
This poster highlights permafrost temperature and active layer trends in the Mackenzie Valley corridor over the past 30 years. Results indicate that
permafrost generally continues to warm at most sites in the corridor. Active layer thickness has generally increased since 2008 and exceeded the long-term mean since 2009. Analysis of long-term changes in thaw penetration and ground surface elevation
for sites in the Mackenzie Delta has also shown significant subsidence at more than half of the sites due to melting of excess ground ice. Data from the permafrost monitoring network has enabled regional characterization of spatial and temporal
variability in active layer thickness and permafrost thermal state. This long-term data collection can inform land-use planning decisions and improve understanding of the impacts of climate change on the permafrost environment. |
| GEOSCAN ID | 327801 |
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