Permafrost thaw affects the chemistry of mountain ponds

Bibliographic Data

ID15546452
AuthorsNicola Colombo (0000-0003-2244-3147, University of Turin, corresponding author), Michael Pettauer (0000-0003-4383-3945, Graz University of Technology, corresponding author), Stefano Brighenti (0000-0001-6111-2311, Free University of Bozen-Bolzano, corresponding author), Danilo Godone (0000-0003-1455-6862, Research Institute for Geo-Hydrological Protection, corresponding author), Franco Salerno (0000-0002-3419-6780, National Research Council, corresponding author), Raffaella Balestrini (0000-0002-5450-1746, Water Research Institute, corresponding author), C A Delconte (Water Research Institute, corresponding author), Emanuele Pintaldi (0000-0001-8345-4283, University of Turin, corresponding author), Andrea Benech (0009-0004-5877-863X, University of Turin, corresponding author), Luca Paro (0009-0009-8326-4936, Agenzia Regionale per la Protezione Ambientale del Piemonte, corresponding author), Maria Martin (0000-0003-1075-7739, University of Turin, corresponding author), A Brunier (Agenzia Regionale per la Protezione Ambientale del Piemonte, corresponding author), Nicolas Guyennon (0000-0002-0306-0610, National Research Council, corresponding author), M Freppaz (0000-0002-4290-6850, University of Turin, corresponding author)
Year2025
Volume20
Issue9
Pages094007-094007
Publication date2025-07-15
Peer ReviewedYes
Open AccessYes
TypeARTICLE
VenueEnvironmental Research Letters (JOURNAL)
Journal identifiersISSN: 1748-9326 • E-ISSN: 1748-9326
PublisherIOP Publishing (PUBLISHER • GB)
DOI10.1088/1748-9326/adeff7
OpenAlexW4412462787
LanguageEN
References cited55

Permafrost is warming and thawing due to climate change. Among the related effects, water quality modification has gained increasing attention globally. Nevertheless, the impacts of diffuse permafrost thaw on water chemistry in high-mountain areas remain largely unexplored. Here, we investigated the seasonal and interannual variability of water chemistry of two close-by ponds located in high-elevation catchments (European Alps, NW Italy) with and without permafrost. We analyzed major ions and stable water isotopes (2014–2022; weekly to monthly sampling during the ice-free season) and leveraged ground thermal measurements in a 30-m deep borehole. We also used geochemical modeling to investigate the impacts of permafrost thaw on dominant weathering processes. Despite similar climatic conditions, lithological characteristics, and water sources contribution, we observed higher concentrations and more pronounced seasonal increases of most solutes in the pond located within the permafrost catchment compared to the pond in the permafrost-free catchment. This was particularly evident for sulfate, with mean concentrations approximately four times higher in the permafrost pond. In the permafrost catchment, progressive warming and thawing during the investigation period enhanced sulfide oxidation, likely due to increased exposure of unweathered, sulfide-bearing rock particles. However, enhanced weathering did not lead to acidification and water quality deterioration due to pH buffering capacity provided by dissolving silicates and carbonates. Global warming is expected to further accelerate permafrost thawing and related chemical weathering in transitional permafrost areas. Water quality issues may arise in catchments with poor acid neutralizing potential of rocks

Earth science · Geography · Permafrost · Physical geography · Chemistry · Climate change and permafrost · Cryospheric studies and observations · Environmental Science · Geology and Paleoclimatology Research · Environmental Chemistry · Geology · Oceanography

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