Lateral thermokarst patterns in permafrost peat plateaus in northern Norway
Subarctic peatlands underlain by permafrost contain significant amounts of organic carbon. Our ability to quantify the evolution of such permafrost landscapes in numerical models is critical for providing robust predictions of the environmental and climatic changes to come. Yet, the accuracy of larg...
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Published in | The cryosphere Vol. 15; no. 7; pp. 3423 - 3442 |
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Main Authors | , , , , , , , , |
Format | Journal Article |
Language | English Norwegian |
Published |
Katlenburg-Lindau
Copernicus GmbH
22.07.2021
Copernicus Publications under license by EGU – European Geosciences Union GmbH Copernicus Copernicus Publications |
Subjects | |
Online Access | Get full text |
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Summary: | Subarctic peatlands underlain by permafrost contain significant amounts of organic carbon. Our ability to quantify the evolution of such permafrost landscapes in numerical models is critical for providing robust predictions of the environmental and climatic changes to come. Yet, the accuracy of large-scale predictions has so far been hampered by small-scale physical processes that create a high spatial variability of thermal surface conditions, affecting the ground thermal regime and thus permafrost degradation patterns. In this regard, a better understanding of the small-scale interplay between microtopography and lateral fluxes of heat, water and snow can be achieved by field monitoring and process-based numerical modeling. Here, we quantify the topographic changes of the SuoÅ¡Å¡jávri peat plateau (northern Norway) over a three-year period using drone-based repeat high-resolution photogrammetry. Our results show thermokarst degradation is concentrated on the edges of the plateau, representing 77 % of observed subsidence, while most of the inner plateau surface exhibits no detectable subsidence. Based on detailed investigation of eight zones of the plateau edge, we show that this edge degradation corresponds to an annual volume change of 0.13±0.07 m.sup.3 yr.sup.-1 per meter of retreating edge (orthogonal to the retreat direction). |
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ISSN: | 1994-0424 1994-0416 1994-0424 1994-0416 |
DOI: | 10.5194/tc-15-3423-2021 |