TY - JOUR

T1 - Groundwater Flow Through Continuous Permafrost Along Geological Boundary Revealed by Electrical Resistivity Tomography

AU - Hornum, Mikkel Toft

AU - Betlem, Peter

AU - Hodson, Andy

N1 - Funding Information: This work was conducted within the Catchment Transport and Cryohydrology Network (CatchNet) funded by the Swedish Nuclear Fuel and Waste Management Company (SKB), and the CLIMAGAS project (Climate forcing of terrestrial methane gas escape through permafrost in Svalbard) funded by the Research Council of Norway (grant no. NRC 294764). PB acknowledges Norwegian CCS Research Centre (NCCS), performed under the Norwegian research program Centres for Environmental‐friendly Energy Research (FME) (grant no. 257579/E20). The authors acknowledge Aart Kroon and Ylva Sjöberg for critical feedback and comments to an earlier version of this manuscript. For help in the field, the authors thank Matt, Linn, Trine, Antoine, Daniela, Erik and UNIS students of the AG340 course. Publisher Copyright: © 2021. The Authors.

PY - 2021/7/20

Y1 - 2021/7/20

N2 - In continuous permafrost regions, pathways for transport of sub-permafrost groundwater to the surface sometimes perforate the frozen ground and result in the formation of a pingo. Explanations offered for the locations of such pathways have so far included hydraulically conductive geological units and faults. On Svalbard, several pingos locate at valley flanks where these controls are apparently lacking. Intrigued by this observation, we elucidated the geological setting around such a pingo with electrical resistivity tomography. The inverted resistivity models showed a considerable contrast between the uphill and valley-sides of the pingo. We conclude that this contrast reflects a geological boundary between low-permeable marine sediments and consolidated strata. Groundwater presumably flows toward the pingo spring through glacially induced fractures in the strata immediately below the marine sediments. Our finding suggests that flanks of uplifted Arctic valleys deserve attention as possible discharge locations for deep groundwater and greenhouse gases to the surface.

AB - In continuous permafrost regions, pathways for transport of sub-permafrost groundwater to the surface sometimes perforate the frozen ground and result in the formation of a pingo. Explanations offered for the locations of such pathways have so far included hydraulically conductive geological units and faults. On Svalbard, several pingos locate at valley flanks where these controls are apparently lacking. Intrigued by this observation, we elucidated the geological setting around such a pingo with electrical resistivity tomography. The inverted resistivity models showed a considerable contrast between the uphill and valley-sides of the pingo. We conclude that this contrast reflects a geological boundary between low-permeable marine sediments and consolidated strata. Groundwater presumably flows toward the pingo spring through glacially induced fractures in the strata immediately below the marine sediments. Our finding suggests that flanks of uplifted Arctic valleys deserve attention as possible discharge locations for deep groundwater and greenhouse gases to the surface.

KW - electrical resistivity tomography

KW - permafrost hydrology

KW - permafrost springs

KW - pingos

KW - sub-permafrost groundwater

U2 - 10.1029/2021GL092757

DO - 10.1029/2021GL092757

M3 - Letter

AN - SCOPUS:85111489976

VL - 48

JO - Geophysical Research Letters

JF - Geophysical Research Letters

SN - 0094-8276

IS - 14

M1 - e2021GL092757

ER -