These data are (1) porewater extractions of cores of the permafrost and active layer of Adventdalen, Svalbard, (2) solid-phase extractions of the same cores, and (3) in-situ porewater sampling from the end of the summer, 2017. The aqueous parameters are: major ions (Ca2+, Mg2+, Na+, K+, Cl-, NO3-, SO42-), Fe(aq), Mn(aq), aqueous CH4 and CO2 concentrations, delta 13C- CH4, acetate, propionic acid, isobutyric acid, butyric acid, isovaleric acid, valeric acid, isocaproic acid, caproic acid, heptanoic acid, pH, oxidation-reduction potential, dissolved oxygen and alkalinity. The solid parameters are: organic carbon, nitrogen, acid volatile sulphur (AVS), chromium-reducible sulphur (CRS), amorphous and nanoparticulate iron (oxyhydr)oxides, crystalline iron (oxyhydr)oxides, iron bound in carbonates, and magnetite.
Funding was provided by the NERC grant NE/M019829/1.
Biogeochemistry, Iron, Methane, Permafrost, Svalbard
|ISO Topic Categories:||
|Role(s)||Investigator, Technical Contact|
|Organisation||University of Sheffield|
|Quality:||Missing values (NAs) in this dataset spreadsheet relate to parameters that were not measured using a particular sampling strategy, e.g. the Macro Rhizons were not used for measuring dissolved gas concentrations, but the spike sampler was.|
|Lineage:||For detailed lineage information, see the Lineage_README file.|
|Data Set Creator||Jones, E.|
|Data Set Title||Permafrost and active layer biogeochemical data from Adventdalen (2015-2017)|
|Data Set Release Date||2019|
|Data Set Publisher||UK Polar Data Centre; British Antarctic Survey, NERC, UKRI|
|Detailed Location||Adventdalen, Svalbard|
|Data Collection:||Major ions (here Ca2+, Mg2+, Na+, K+, Cl-, NO3-, SO42-) were determined by ion chromatography on a Dionex ion chromatograph, DX 90, with a detection limit of 0.02 mg l-1 for the lowest, undiluted analysis. The precision errors were <5 % for the mid-range standards.
Trace metals were determined on 5 ml sample acidified with 50 ul reagent grade HNO3- (AnalaR 65% Normapur, VWR, IL, USA) , using Inductively Coupled Plasma Mass Spectrometry or ICPMS (PerkinElmer Elan DRC II, MA, USA). The precision errors for repeat analyses of mid-range standards were <5%, and the detection limits were 1.0 ug l-1. Concentrations were corrected for the blanks and normalised to the pore water content.
Water isotopes. The samples were analysed at the University of East Anglia, using a Picarro 1102i analyser, by direct injection of 2.6 microlitres of water. Samples were measured together with 2 USGS standards: USGS 64444 and USGS 67400 and UEA NTW internal laboratory standard. Using the calibration line defined by the USGS standards the true composition of the samples was calculated.
Volatile Fatty Acids. The Eppendorf tubes containing the samples were centrifuged at 13000 rpm for 5 minutes. 1 ml of the supernatant was pipetted into a GC vial. The samples, blanks and standards were acidified with 15 ul analytical grade orthophosphoric acid to ensure that the acid/salt ratio (i.e. acetic acid versus acetate ions) was weighted towards the acid. The Thermo ScientificTM TRACETM 1300 Gas Chromatograph was calibrated using dilutions of Acetic acid as well as dilutions of a Volatile Acid Mix (46975-U, Sigma) composed of Acetic acid, Propionic acid, Isobutyric acid, Butyric acid, Isovaleric acid, Valeric acid, Isocaproic acid, Caproic acid and Heptanoic acid. The R2 for all calibrations was >0.99, and the detection limits, calculated as the standard deviation of the 100 uM standard (n=5), were 15.8 uM for acetate, 30.2 uM for propionic acid, 26.8 uM for isobutyric acid, 26.7 uM for butyric acid, 26.7 uM for isovaleric acid, 31.2 uM for valeric acid, 29.0 uM for isocaproic acid, 32.7 uM for caproic acid and 36.7 uM for heptanoic acid.
Methane and carbon dioxide samples were measured on a Shimadzu GC-2014 Gas Chromatograph, using a 100 ul sample loop.
Sulphate and methane isotopes. The dry samples were weighed into tin or silver capsules for analysis of δ34SSO4 and δ18OSO4 respectively. Isotopic analysis was undertaken by Elemental Analyser (Elementar Pyrocube) linked to a continuous flow isotope ratio mass spectrometer (Isoprime 100 with dual inlet capability for injection of monitoring gases). For methane, an Agilent 7890B GC attached to an Isoprime100 Isotope Ratio Mass Spectrometer (IRMS) was employed.
|Data Storage:||The data is stored as an excel file (105 Kb) with four spreadsheets (including a metadata spreadsheet).|
|Access Constraints:||No restrictions apply.|
|Use Constraints:||This data is governed by the NERC data policy http://www.nerc.ac.uk/research/sites/data/policy/ and supplied under Open Government Licence v.3 http://www.nationalarchives.gov.uk/doc/open-government-licence/version/3/.|