Preprints
https://doi.org/10.5194/tc-2022-189
https://doi.org/10.5194/tc-2022-189
 
20 Oct 2022
20 Oct 2022
Status: this preprint is currently under review for the journal TC.

Characteristics and evolution of bedrock permafrost in the Sisimiut mountain area, West Greenland

Marco Marcer1,2, Pierre-Allain Duvillard3,4, Sona Tomaškovicová1, Steffen Ringsø Nielsen2,5, André Revil4, and Thomas Ingeman-Nielsen1 Marco Marcer et al.
  • 1DTU Sustain,Bygningstorvet, Bygning 115, 2800 Kgs. Lyngby, Denmark
  • 2Arctic DTU, Siimuup Aqqutaa 32, B-1280, 3911 Sisimiut, Greenland
  • 3Styx4D, 12 Allée du lac de Garde, Le Bourget du lac, France
  • 4EDYTEM, Université Savoie Mont-Blanc, CNRS (UMR 5204), 73370 Le Bourget du Lac, France
  • 5KTI Råstofskolen - Greenland School of Minerals and Petroleum, Adammip Aqq. 2, 3911 Sisimiut, Greenland

Abstract. Bedrock permafrost is a feature of cold mountain ranges that was found responsible for the increase of rock fall and landslide activity in several regions across the globe. In Greenland, bedrock permafrost has received so far little attention from the scientific community, despite mountains are a predominant feature on the ice-free coastline and landslide activity is significant. With this study, we aim to move a first step towards the characterization of bedrock permafrost in Greenland. Our study area covers 100 km2 of mountain terrain around the town of Sisimiut – 68° N on the West Coast. We first acquire surface ground temperature data from 2020–2021 to model bedrock surface temperatures time series from weather forcing on the period 1850–2022. Using a topographical downscaling method based on digital elevation model, we then create climatic boundary conditions for 1D and 2D heat transfer numerical simulations at the landscape level. In this way we obtain permafrost distribution maps and ad-hoc simulations for complex topographies. Our results are validated by comparison with temperature data from two lowland boreholes (100 m depth) and geophysical data describing freezing/unfreezing conditions across a mid-elevation mountain ridge. Finally, we use regional carbon pathway scenarios 2.6 and 8.5 to evaluate future evolution of ground temperatures to 2100. Our results indicate a sporadic permafrost distribution up to roughly 400 m.a.s.l., while future scenarios suggest a decline of deep frozen bodies up to 800 m.a.s.l., i.e. the highest summits in the area.

Marco Marcer et al.

Status: open (until 15 Dec 2022)

Comment types: AC – author | RC – referee | CC – community | EC – editor | CEC – chief editor | : Report abuse
  • RC1: 'Comment on tc-2022-189', Anonymous Referee #1, 24 Nov 2022 reply

Marco Marcer et al.

Marco Marcer et al.

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Short summary
This study models present and future bedrock temperatures in the mountains near Sisimiut, creating for the first time knowledge on mountain permafrost in Greenland. Bedrock is mostly frozen, but also has temperatures near 0 C, making it very fragile to climate changes. Future climatic scenarios indicate a dramatic reduction in frozen bedrock areas. Since mountain permafrost thaw is linked to an increase in landslides, these results call for more efforts addressing bedrock permafrost in Greenland