Aluminium in glacial meltwater demonstrates an association with nutrient export (Werenskiöldbreen, Svalbard)

Abstract

The aluminium (Al) cycle in glacierised basins has not received a great deal of attention in studies of biogeochemical cycles. As Al may be toxic for biota, it is important to investigate the processes leading to its release into the environment. It has not yet been ascertained whether filterable Al (passing through a pore size of 0.45 μm) is incorporated into biogeochemical cycles in glacierised basins. Our study aims to determine the relationship between the processes bringing filterable Al and glacier‐derived filterable nutrients (particularly Fe and Si) into glacierised basins. We investigated the Werenskiöldbreen basin (44.1 km2, 60% glacierised) situated in SW Spitsbergen, Svalbard. In 2011, we collected meltwater from a subglacial portal at the glacier front and at a downstream hydrometric station throughout the ablation season. The Al concentration, unchanged between the subglacial system and proglacial zone, reveals that aluminosilicate weathering is a dominant source of filterable Al under subglacial conditions. By examining the Al:Fe ratio compared with pH and the sulphate mass fraction index, we found that the proton source for subglacial aluminosilicate weathering is mainly associated with sulphide oxidation and, to a lesser degree, with hydrolysis and carbonation. In subglacial outflows and in the glacial river, Al and Fe are primarily in the forms of Al(OH)4‐ and Fe(OH)3. The annual filterable Al yield (2.7 mmol m‐2) was of a magnitude similar to that of nutrients such as filterable Fe (3.0 mmol m‐2) and lower than that of dissolved Si (18.5 mmol m‐2). Our results show that filterable Al concentrations in meltwater are significantly correlated to filterable and dissolved glacier‐derived nutrients (Fe and Si, respectively) concentrations in glaciers worldwide. We conclude that a potential bioavailable Al pool derived from glacierised basins may be incorporated in biogeochemical cycles, as it is strongly related to the concentrations and yields of glacier‐derived nutrients.

Patterns in Microbial Assemblages Exported From the Meltwater of Arctic and Sub-Arctic Glaciers

“…Thus, while exported assemblage structure appears regionally specific, and probably reflects INTRODUCTION Glacier meltwater streams connect discrete cryosphere habitats with downstream freshwater and marine ecosystems across the Northern Hemisphere (e.g., O'Neel et al, 2015;Milner et al, 2017). In addition to exporting freshwater, glaciers and ice sheets also subsidize microbial productivity and respiration through the downstream delivery of particulate and dissolved material such as carbon (Bhatia et al, 2013a;Lawson et al, 2014;Kohler et al, 2017), macro-and micronutrients (Bhatia et al, 2013b;Hawkings et al, 2015;Dubnick et al, 2017a), and other weathering products Hatton et al, 2019a;Stachnik et al, 2019). While recent progress has been made in determining factors that control the magnitude of these biogeochemical fluxes, important clues into solute generation and the operation of the subglacial drainage system may be uncovered through the investigation of more qualitative characteristics of these exports.…”

Investigation on the Sources and Impact of Trace Elements in the Annual Snowpack and the Firn in the Hansbreen (Southwest Spitsbergen)

“…The lower amount of water-soluble fraction in the firn core compared to the snow pit (FC\SP < 1) could be the result of removing the soluble fraction during snow pack melting. The late spring melting could remove the soluble Al fraction (Stachnik et al, 2019), leaving the insoluble Al fraction trapped in the ice. This might also occur for Fe, which is abundant in the mineral particle lattice.…”

“…The annual snowpack is a critical component of the cryosphere and interfaces with most environmental spheres (hydrosphere, atmosphere, pedosphere and ecosphere) in Svalbard (Gallet et al, 2019). For example, the impact of the release of elements and compounds during the melting season, in particular biologically active elements such as iron and phosphorus, on the surface oceanic water composition, highlights the importance of snowmelt on ecosystems (Stachnik et al, 2019). Therefore, investigating the chemical composition of snow and the underlying processes controlling it is fundamental for constraining the impact of snowpacks on down-stream ecosystems.…”

Effects of biotransport and hydro-meteorological conditions on transport of trace elements in the Scott River (Bellsund, Spitsbergen)

“…The presence of trace elements in surface water was studied in different components of the Svalbard Archipelago’s environment such as: glacier surface ice ( Chmiel, Reszka & Rysiak, 2009 ; Lehmann et al, 2016 ), snow deposited on glacier surface ( Kozioł et al, 2021 ), supraglacial streams ( Jóźwiak, 2007 ), glacial rivers ( Chmiel, Reszka & Rysiak, 2009 ; Zhang et al, 2015 ; Kozak et al, 2016 ; Kosek et al, 2019 ; Stachnik et al, 2019 ), creeks of glacier-free catchments ( Chmiel, Reszka & Rysiak, 2009 ; Kozak et al, 2015 ; Szumińska et al, 2018 ) and lakes ( Chmiel, Reszka & Rysiak, 2009 ; Szumińska et al, 2018 ; Kosek et al, 2019 ). The glacier retreat and thawing of permafrost accelerated rapidly in the 21 st century when the mean air temperature in High Arctic started to increase twice as fast as in any other place on Earth ( Vaughan et al, 2013 ; Szumińska et al, 2018 ; Amélineau et al, 2019 ).…”