Geophysical mapping of palsa peatland permafrost

TY - JOUR

T1 - Geophysical mapping of palsa peatland permafrost

AU - Sjöberg, Y.

AU - Marklund, P.

AU - Pettersson, R.

AU - Lyon, S. W.

PY - 2015

Y1 - 2015

N2 - Permafrost peatlands are hydrological and biogeochemical hotspots in the discontinuous permafrost zone. Non-intrusive geophysical methods offer a possibility to map current permafrost spatial distributions in these environments. In this study, we estimate the depths to the permafrost table 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, which is indicative of lower ground ice content at these locations. These results highlight the added value of combining geophysical techniques for assessing spatial distributions of permafrost within the rapidly changing sporadic permafrost zone. For example, based on a back-of-the-envelope calculation for the site considered here, we estimated that the permafrost could thaw completely within the next 3 centuries. Thus there is a clear need to benchmark current permafrost distributions and characteristics, particularly in under studied regions of the pan-Arctic.

AB - Permafrost peatlands are hydrological and biogeochemical hotspots in the discontinuous permafrost zone. Non-intrusive geophysical methods offer a possibility to map current permafrost spatial distributions in these environments. In this study, we estimate the depths to the permafrost table 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, which is indicative of lower ground ice content at these locations. These results highlight the added value of combining geophysical techniques for assessing spatial distributions of permafrost within the rapidly changing sporadic permafrost zone. For example, based on a back-of-the-envelope calculation for the site considered here, we estimated that the permafrost could thaw completely within the next 3 centuries. Thus there is a clear need to benchmark current permafrost distributions and characteristics, particularly in under studied regions of the pan-Arctic.

U2 - 10.5194/tc-9-465-2015

DO - 10.5194/tc-9-465-2015

M3 - Journal article

AN - SCOPUS:84924202577

SN - 1994-0416

VL - 9

SP - 465

EP - 478

JO - Cryosphere

JF - Cryosphere

IS - 2

ER -