Description
Summary:Adventdalen is a medium-sized (513 km2) catchment in continuous permafrost zone of central Spitsbergen. It has 11.7 % glacier cover, a large flat valley floor comprised of uplifted, glaciomarine sediments, covered in the lower part by a veneer of aeolian sediments up to 4 m thick. The geology of the catchment is dominated by sandstones, shales and carbonates. Freshwater samples were collected typically every second day throughout the principal runoff season (late May until early September) during 2015 and 2016 from a downstream site located at the head of the delta. Analysis of major ions (by ion chromatography) and minor constituents (trace metals by icpms and silica by colorimetric analysis). : Samples for trace metal analysis were filtered using pre-rinsed 0.45µm Whatman Puradisc Aqua 30 syringe filters and stored in 15mL Eppendorf Tubes after immediate acidification to pH ~ 1.7 using reagent grade HNO3 (AnalaR 65% Normapur, VWR, IL, USA). Samples for major ions were stored in sterile 50 mL centrifuge tube after filtration and rinsing. Analysis of Fl⁻, Cl⁻, NO₃⁻, and SO₄²⁻ employed a Dionex ICS90 ion chromatography module calibrated in the range 0 - 2 mg/L. Precision errors for these ions ranged from 0.9 % (SO₄²⁻) to 1.6 % (PO₄³⁻) and the limit of detection (three times the standard deviation of ten blanks) was < 0.05 mg/L. A Skalar Autoanalyser, was employed for quantification of dissolved Si (detection limits 0.1 mg/L, available for 2015 only) using standard colorimetric methods. Concentrations of cations Ca²⁺, Mg²⁺, Na⁺ and K⁺ were determined by ICP-OES using a Thermo Fisher iCAP 7400 Radial ICP-OES with an internal standard of 1ppm Y, a limit of detection of 0.07 mg/L or better and precision errors < 3.65%. For Al, Co, Fe, Mn, Ni, Sr, Ti, and Zn we employed a Thermo Fisher iCAPQc ICP-MS, with internal standard of 1 ppb Rh, a limit of detection < 0.7 ppb and precision 3.2% or better. Accuracy of each method was assessed by analysing freshwater certified reference standards throughout the analyses. : For missing analyses or lost samples, cells have been left blank. Results below detection limit are marked "b.d."