Publication Date:
2014-10-14
Description:
Geophysical mapping of palsa peatland permafrost The Cryosphere Discussions, 8, 5137-5168, 2014 Author(s): Y. Sjöberg, P. Marklund, R. Pettersson, and S. W. Lyon Permafrost peatlands are hydrological and biogeochemical hotspots in the discontinuous permafrost zone. Non-intrusive geophysical methods offer possibility to map current permafrost spatial distributions in these environments. In this study, we estimate the depths to the permafrost table surface and base across a peatland in northern Sweden, using ground penetrating radar and electrical resistivity tomography. Seasonal thaw frost tables (at ~0.5 m depth), taliks (2.1–6.7 m deep), and the permafrost base (at ~16 m depth) could be detected. Higher occurrences of taliks were discovered at locations with a lower relative height of permafrost landforms indicative of lower ground ice content at these locations. These results highlight the added value of combining geophysical techniques for assessing spatial distribution of permafrost within the rapidly changing sporadic permafrost zone. For example, based on a simple thought experiment for the site considered here, we estimated that the thickest permafrost could thaw out completely within the next two centuries. There is a clear need, thus, to benchmark current permafrost distributions and characteristics particularly in under studied regions of the pan-arctic.
Print ISSN:
1994-0432
Electronic ISSN:
1994-0440
Topics:
Geography
,
Geosciences
