Porewater oxygen profiles in surface sediments of the North Atlantic Basin during RV Maria S. Merian cruise MSM96

DOI

Vertical profiles of dissolved oxygen (O2) concentrations in the surface sediment of the North Atlantic Basin were acquired during MSM96 through ex-situ voltametric measurements during this research cruise. For every multicorer station, one liner was selected and transported to the on-board cool room immediately for analysis at 5°C. At some stations, a second core was analyzed for validation and to achieve better measurement resolution. Measurements were carried out through cyclic voltammetry (start: -100 mV, vertex: -1900 mV, start: -100 mV, scan rate: 500 mv/s) with Hg/Au microelectrodes (100 µm diameter) in a 3-electrode configuration with an Ag/AgCl pseudoreference electrode and a Pt counter electrode using a modified custom version of the DStat open source potentiostat (Dryden & Wheeler, 2015; doi:10.1371/journal.pone.0140349). Working electrodes were polished and Hg-plated prior to the research cruise according to the method by Brendel & Luther III (1995; doi:10.1021/es00003a024) and repolished (using diamond polishing plates of 5, 1 and 0.25 µm grit) and plated (180s at -100mV in 0.1M Hg(NO3)2 solution) on board when degradation of the signal was detected (twice over the duration of the cruise). Measurements were calibrated to 100% O2 saturation in bottom water at equilibrium with the atmosphere after recording air pressure and temperature to calculate dissolved O2 concentration as well as 0% O2 saturation in bottom water that was purged of oxygen by bubbling with nitrogen (N2) gas. The sensor was moved vertically on a linear axis with a stepper motor through an automated control system hosted on a Raspberry Pi control unit.

Identifier
DOI https://doi.org/10.1594/PANGAEA.931647
Related Identifier https://doi.org/10.48433/cr_msm96
Metadata Access https://ws.pangaea.de/oai/provider?verb=GetRecord&metadataPrefix=datacite4&identifier=oai:pangaea.de:doi:10.1594/PANGAEA.931647
Provenance
Creator Fröhberg, Nico; Paul, Sophie Anna Luise
Publisher PANGAEA - Data Publisher for Earth & Environmental Science
Publication Year 2021
Funding Reference Horizon 2020, 818123
Rights Creative Commons Attribution 4.0 International; https://creativecommons.org/licenses/by/4.0/
OpenAccess true
Representation
Language English
Resource Type Dataset
Format text/tab-separated-values
Size 44830 data points
Discipline Earth System Research
Spatial Coverage (-17.700W, 37.908S, -14.512E, 48.100N); North Atlantic Ocean
Temporal Coverage Begin 2020-10-14T20:46:02Z
Temporal Coverage End 2020-11-06T13:39:04Z