| Title | Growth of a young pingo in the Canadian Arctic observed by RADARSAT-2 interferometric satellite radar |
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| Author | Samsonov, S V ;
Lantz, T C; Kokelj, S V; Zhang, Y |
| Source | The Cryosphere vol. 10, 2016 p. 799-810, https://doi.org/10.5194/tc-10-799-2016  Open Access |
| Image |  |
| Year | 2016 |
| Alt Series | Earth Sciences Sector, Contribution Series 20150078 |
| Publisher | Copernicus GmbH |
| Document | serial |
| Lang. | English |
| Media | paper; on-line; digital |
| File format | pdf |
| Province | Northwest Territories |
| NTS | 107E/07 |
| Area | Arctic; Tuktoyaktuk |
| Lat/Long WENS | -133.2000 -133.1333 69.4333 69.3667 |
| Subjects | geophysics; surficial geology/geomorphology; satellites; satellite imagery; pingos; glacial landforms; glacial features; deformation; permafrost; freezing ground; ground ice; modelling;
RADARSAT-2 |
| Illustrations | location maps; satellite images; tables; plots |
| Program | Remote Sensing Science |
| Released | 2016 04 15 |
| Abstract | Advancements in radar technology are increasing our ability to detect Earth surface deformation in permafrost environments. In this paper we use satellite Differential Interferometric Synthetic Aperture
Radar (DInSAR) to describe the growth of a large, relatively young pingo in the Tuktoyaktuk Coastlands. High-resolution RADARSAT- 2 imagery (2011-2014) analyzed with the Multidimensional Small Baseline Subset (MSBAS) DInSAR revealed a maximum 2.7 cm
yr-1 of domed uplift located in a drained lake basin. Satellite measurements suggest that this feature is one of the largest diameter pingos in the region that is presently growing. Observed changes in elevation were modeled as a 348 290m uniformly
loaded elliptical plate with clamped edge. Analysis of historical aerial photographs suggested that ground uplift at this location initiated sometime between 1935 and 1951 following drainage of the residual pond. Uplift is largely due to the growth
of intrusive ice, because the 9% expansion of pore water associated with permafrost aggradation into saturated sands is not sufficient to explain the observed short- and long-term deformation rates. The modeled thickness of ice-rich permafrost using
the Northern Ecosystem Soil Temperature (NEST) was consistent with the maximum height of this feature. Modeled permafrost aggradation from 1972 to 2014 approximated elevation changes estimated from aerial photographs for that time period. Taken
together, these lines of evidence indicate that uplift is at least in part a result of freezing of the sub-pingo water lens. Seasonal variations in the uplift rate seen in the DInSAR data closely match the modeled seasonal pattern in the deepening
rate of freezing front. This study demonstrates that interferometric satellite radar can detect and contribute to understanding the dynamics of terrain uplift in response to permafrost aggradation and ground ice development in remote polar
environments. The present-day growth rate is smaller than predicted by the modeling and no clear growth is observed at other smaller pingos in contrast with field studies performed mainly before the 1990s. Investigation of this apparent discrepancy
provides an opportunity to further develop observation methods and models. |
| Summary | (Plain Language Summary, not published)
The growth of a previously unknown pingo in the Tuktoyaktuk Peninsula Area is observed for the first time by interferometric satellite radar. The
2011-2014 high-resolution RADARSAT-2 imagery revealed ground uplift located in a lake bottom. The detected deformation rate is larger than heave induced by the uniform permafrost aggradation. Historical stereophotos and field observations confirmed
that the detected feature is a growing young pingo. This study demonstrates that satellite radar interferometry can successfully contribute to understanding the dynamics of pingos in terrestrial and possibly martian environments. |
| GEOSCAN ID | 296556 |
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