Chemistry of eastern tropical Atlantic porewater

Distributions of pore water O2, NO-2, NO-3, NH+4, Si(OH)4, PO[3-]4, Mn[2+], F-, and T.A. were determined at 15 stations in the eastern equatorial Atlantic. While overall profile characteristics are consistent with previous models of organic matter diagenesis, profile shapes suggest that a deep react...

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Bibliographic Details
Main Authors: Jahnke, Richard A, Emerson, Steven R, Reimers, Clare, Schuffert, Jeffrey D, Ruttenberg, K, Archer, David E
Format: Dataset
Language:English
Published: PANGAEA 1989
Subjects:
10BC35-2
11.5BC46-2
11BC39
11H43
12BC47-2
12BC48-1
12H50
13BCP56
14BC62
15BC64
1BC1-2
1BC4-4
2BC5-1
4BC14-2
4H10
4IMP11
6BC20-2
6BCP24
7BC25
7BC26-1
8BC27-3
BC
BCP
Box corer
Box corer with microelectrode
H
IMP
In situ oxygen microprofiler
Punch core
Silicon Cycling in the World Ocean
SINOPS
Pacific
North Atlantic
Online Access:https://doi.pangaea.de/10.1594/PANGAEA.730527
https://doi.org/10.1594/PANGAEA.730527
Description
Summary:Distributions of pore water O2, NO-2, NO-3, NH+4, Si(OH)4, PO[3-]4, Mn[2+], F-, and T.A. were determined at 15 stations in the eastern equatorial Atlantic. While overall profile characteristics are consistent with previous models of organic matter diagenesis, profile shapes suggest that a deep reaction layer, rich in organic C, is also present at many sites. While it is unlikely that the oxidation of organic C in this layer has had a major effect on the ocean C cycle, pore water profile shapes are significantly altered. Despite exposure to seawater SO[2-]4 concentrations for > 1000 years, decomposition of the organic matter in the layer appears to be restricted to oxic and suboxic processes. These results suggest major differences in organic carbon decomposition and preservation under oxic/suboxic and anoxic conditions. Present-day benthic fluxes are largest adjacent to the eastern boundary coastal upwelling region and similar in magnitude to values reported for the eastern Pacific. Preliminary estimates suggest that the benthic respiration in the eastern 1/3 of the North Atlantic south of 20°N may alone account for >20% of the total deep North Atlantic respiration. Combining these results with estimates of organic C burial and deep water-column decomposition suggests that this region is a major location of organic C input into the deep sea.

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