부산대학교 도서관

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. Plain Language Summary: In the High Arctic, considerable amounts of greenhouse gasses are stored below permanently frozen ground (permafrost) in deep groundwater systems. The permafrost usually retains these greenhouse gasses and groundwaters deep in the subsurface, but flow to the surface and atmosphere can take place where unfrozen holes form hydrological pathways through the permafrost. The common explanations offered for the locations of such pathways include geological layers and faults that are permeable for groundwater flow. However, on Svalbard, several active and relict groundwater springs locate at valley flanks where none of the common explanations seem suitable. Intrigued by this observation, we investigated the geological setting around such a spring with measurements of the electrical resistivity of the subsurface. In line with existing geological knowledge, our results show that the spring locates exactly at the boundary between low‐permeable marine valley sediments and older consolidated sediments. Groundwater presumably flows toward the spring through glacially induced fractures in the consolidated sediments. Our finding suggests that flanks of uplifted Arctic valleys deserve attention as possible outflow locations for deep groundwater and greenhouse gasses to the surface and atmosphere. Key Points: Electrical resistivity surveys link the location of a pingo spring to the transition between marine valley sediments and consolidated strataGroundwater flow toward the pingo spring most likely follows glacially induced fractures in consolidated strata produced during glaciationFlanks of uplifted Arctic valleys deserve attention as discharge locations for sub‐permafrost groundwater and dissolved greenhouse gases [ABSTRACT FROM AUTHOR]