Epibenthic foraminiferal δ¹³C in the Recent deep Arctic Ocean

DOI

Low planktic and benthic d18O and d13C values in sediments from the Nordic seas of cold stadials of the last glaciation have been attributed to brines, formed similar to modern ones in the Arctic Ocean. To expand on the carbon isotopes of this hypothesis I investigated benthic d13C from the modern Arctic Ocean. I show that mean d13C values of live epibenthic foraminifera from the deep Arctic basins are higher than mean d13C values of upper slope epibenthic foraminifera. This agrees with mean high d13C values of dissolved inorganic carbon (DIC) in Arctic Bottom Water (ABW), which are higher than mean d13CDIC values from shallower water masses of mainly Atlantic origin. However, adjustments for oceanic 13C-Suess depletion raise subsurface and intermediate water d13CDIC values over ABW d13CDIC ones. Accordingly, during preindustrial Holocene times, the d13CDIC of ABW was as high or higher than today, but lower than the d13CDIC of younger subsurface and intermediate water. If brine-enriched water significantly ventilated ABW, brines should have had high d13CDIC values. Analogously, high-d13CDIC brines may have been formed in the Nordic seas during warm interstadials. During cold stadials, when most of the Arctic Ocean was perennially sea-ice covered, a cessation of high-d13CDIC brine rejection may have lowered d13CDIC values of ABW, and ultimately the d13CDIC in Nordic seas intermediate and deep water. So, in contrast to the idea of enhanced brine formation during cold stadials, the results of this investigation imply that a cessation of brine rejection would be more likely.

Exact sampling date for cruises AOS94 and ARA03B are not given. All samples, except those from PRV Araon, were Rose Bengal stained. Includes 12 C. wuellerstorfi d13C values from unstained surface sediment samples taken in 1994 in the Mendeleyev Ridge area of the Amerasian basin (Poore et al., 1999).

Supplement to: Mackensen, Andreas (2013): High epibenthic foraminiferal d13C in the recent deep Arctic Ocean: implications for ventilation and brine release during stadials. Paleoceanography, 28(3), 574-584

Identifier
DOI https://doi.org/10.1594/PANGAEA.819226
Related Identifier IsSupplementTo https://doi.org/10.1002/palo.20058
Related Identifier IsDocumentedBy https://doi.org/10.1594/PANGAEA.819248
Metadata Access https://ws.pangaea.de/oai/provider?verb=GetRecord&metadataPrefix=datacite4&identifier=oai:pangaea.de:doi:10.1594/PANGAEA.819226
Provenance
Creator Mackensen, Andreas ORCID logo
Publisher PANGAEA
Publication Year 2013
Rights Creative Commons Attribution 3.0 Unported; https://creativecommons.org/licenses/by/3.0/
OpenAccess true
Representation
Resource Type Supplementary Dataset; Dataset
Format text/tab-separated-values
Size 305 data points
Discipline Earth System Research
Spatial Coverage (-179.836W, 65.845S, 179.047E, 88.873N); Arctic Ocean; Mendeleev Ridge, Arctic Ocean; Lomonosov Ridge, Arctic Ocean; Barents Sea; North Greenland Sea; Beaufort Sea; Kolbeinsey Ridge; Greenland Sea; Greenland Shelf; Hovgaard Fracture Zone; Jan Mayen Fracture Zone; Greenland Slope; Scoresby Sund; Svalbard; Yermak Plateau; Nansen Basin; Gakkel Ridge, Arctic Ocean; Morris Jesup Rise; Northeast Greenland; Laptev Sea; Laptev Sea, Taymyr Island; Norwegian-Greenland Sea; Hochstetter Bugten, East Greenland; East Greenland Sea; Kaiser-Franz-Josef-Fjord, East Greenland; Kong-Oskar-Fjord, East Greenland; Sofia Sund, East Greenland; Denmark Strait; Ø Fjord, East Greenland; Aegir Ridge, Norwegian-Greenland Sea; W Spitzbergen; East Greenland continental slope
Temporal Coverage Begin 1988-06-02T00:00:00Z
Temporal Coverage End 2012-08-01T00:00:00Z