Major ions and trace metals in glacial meltwaters nearby Ny-Ålesund, Svalbard

Abstract Ny-Ålesund, located in Arctic Svalbard, is one of the most sensitive areas on Earth under global warming. Accelerated glacier ablation has become remarkable in Ny-Ålesund in recent years. Glacial meltwaters discharge a significant amount of materials to the ocean, affecting downstream ecosystems and adjacent oceans. In August 2015, various water samples were taken near Ny-Ålesund, including proglacial meltwater, supraglacial meltwater, englacial meltwater, and groundwater. Trace metals (Al, Cr, Mn, Fe, Co, Cu, Zn, Cd, and Pb), major ions, alkalinity, pH, dissolved oxygen, water temperature and electric conductivity were also measured. Major ions were mainly controlled by chemical weathering intensity and reaction types, while trace metals were influenced by both chemical weathering and physicochemical control upon their mobility. Indeed, we found Brøggerbreen was dominated by carbonation of carbonate for carbonate weathering, while Austre Lovénbreen and Pedersonbreen were dominated by sulfide oxidation coupled with carbonate dissolution, with a doubled silicate weathering. The higher enrichment of trace metals in supraglacial meltwater compared to proglacial meltwater suggested anthropogenic pollution from atmospheric deposition. In proglacial meltwater, principal component analysis indicated that trace metals like Cr, Al, Co, Mn and Cd were correlated to chemical weathering. This implies that under the accelerated glacier retreating, glacier derived chemical components are subjected to the future changes in weathering types and intensity.