Noble gas and isotope geochemistry in western Canadian Arctic watersheds: tracing groundwater recharge in permafrost terrain | Gaz rares et géochimie isotopique sur des bassins versants de l’Arctique Canadien : traçage de recharge de nappe dans le permafrost Gases nobles y geoquímica isotópica en cuencas del Ártico Occidental de Canadá: trazadores de recarga de agua subterránea en terrenos permafrost 稀有气体和同位素地球化学应用于加拿大西部寒区流域:示踪多年冻土地带地下水补给 Geoquímica isotópica e de gases nobres em bacias hidrográficas do Ártico Canadiano ocidental: traçagem da recarga de águas subterrâneas em terrenos de permafrost
2013
Utting, Nicholas | Lauriol, Bernard | Mochnacz, Neil | Aeschbach-Hertig, Werner | Clark, Ian
In Canada’s western Arctic, perennial discharge from permafrost watersheds is the surface manifestation of active groundwater flow systems with features including the occurrence of year-round open water and the formation of icings, yet understanding the mechanisms of groundwater recharge and flow in periglacial environments remains enigmatic. Stable isotopes (δ¹⁸O, δD, δ¹³CDIC), and noble gases have proved useful to study groundwater recharge and flow of groundwater which discharges along rivers in Canada’s western Arctic. In these studies of six catchments, groundwater recharge was determined to be a mix of snowmelt and precipitation. All systems investigated show that groundwater has recharged through organic soils with elevated PCO₂, which suggests that recharge occurs largely during summer when biological activity is high. Noble gas concentrations show that the recharge temperature was between 0 and 5 °C, which when considered in the context of discharge temperatures, suggests that there is no significant imbalance of energy flux into the subsurface. Groundwater circulation times were found to be up to 31 years for non-thermal waters using the ³ H-³He method.
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