Respiration and dissolution in sediments of the western Atlantic ...

• Main Authors: Hales, Burke, Emerson, Steven R, Archer, David E
• Format: Article in Journal/Newspaper
• Language: English
• Published: PANGAEA 1994
• Subjects: Bottle, Niskin; Soil combustion; Box corer; ADEPDCruises; Atlantic Data Base for Exchange Processes at the Deep Sea Floor ADEPD; North Atlantic
• Online Access: https://dx.doi.org/10.1594/pangaea.730420; https://doi.pangaea.de/10.1594/PANGAEA.730420

We present in situ microelectrode measurements of sediment formation factor and porewater oxygen and pH from six stations in the North Atlantic varying in depth from 2159 to 5380 m. A numerical model of the oxygen data indicates that fluxes of oxygen to the sediments are as much as an order of magnitude higher than benthic chamber flux measurements previously reported in the same area. Model results require dissolution driven by metabolic CO2 production within the sediments to explain the pH data; even at the station with the most undersaturated bottom waters >60% of the calcite dissolution occurs in response to metabolic CO2. Aragonite dissolution alone cannot provide the observed buffering of porewater pH, even at the shallowest station. A sensitivity test of the model that accounts for uncertainties in the bottom water saturation state and the stoichiometry between oxygen consumption and CO2 production during respiration constrains the dissolution rate constant for calcite to between 3 and 30% day**-1, ... : Supplement to: Hales, Burke; Emerson, Steven R; Archer, David E (1994): Respiration and dissolution in the sediments of the western North Atlantic: estimates from models of in situ microelectrode measurements of porewater oxygen and pH. Deep Sea Research Part I: Oceanographic Research Papers, 41(4), 695-719 ...