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Groundwater Flow Through Continuous Permafrost Along Geological Boundary Revealed by Electrical Resistivity Tomography
Author(s) -
Hornum Mikkel Toft,
Betlem Peter,
Hodson Andy
Publication year - 2021
Publication title -
geophysical research letters
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 2.007
H-Index - 273
eISSN - 1944-8007
pISSN - 0094-8276
DOI - 10.1029/2021gl092757
Subject(s) - permafrost , geology , electrical resistivity tomography , groundwater , geomorphology , groundwater flow , thermokarst , electrical resistivity and conductivity , aquifer , oceanography , geotechnical engineering , electrical engineering , engineering
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.