KOPRI Repository

Taxon-specific epibenthic foraminiferal d18O in the Arctic Ocean: realtionship to water mass, deep circulation, and brine formation

Cited 6 time in scopus
Metadata Downloads
Title
Taxon-specific epibenthic foraminiferal d18O in the Arctic Ocean: realtionship to water mass, deep circulation, and brine formation
Other Titles
북극해에 산출되는 저서성 유공충 산소동위원소 비: 수괴, 심층순환 및 고염수 형성과의 관계
Authors
Andreas Mackensen
Lee, Mi Jung
Keywords
Brines; Nordic Sea; Oxygen isotopes; Pleistocene; Proxy
Issue Date
2014
Citation
Andreas Mackensen, Lee, Mi Jung. 2014. "Taxon-specific epibenthic foraminiferal d18O in the Arctic Ocean: realtionship to water mass, deep circulation, and brine formation". MARINE MICROPALEONTOLOGY, 113(1): 34-43.
Abstract
We determined δ18OCib values of live (Rose Bengal stained) and dead epibenthic foraminifera Cibicidoides wuellerstorfi, Cibicides lobatulus, and Cibicides refulgens in surface sediment samples from the Arctic Ocean and the Greenland, Iceland, and Norwegian seas (Nordic Sea). This is the first time that a comprehensive δ18OCib data set is generated and compiled from the Arctic Ocean. For comparison, we defined Atlantic Water (AW), upper Arctic Bottom Water (uABW), and ABW by their temperature/salinity characteristics and calculated mean equilibrium calcite δ18Oequ from summer sea-water δ18Ow and in situ temperatures accordingly. As a result, in the Arctic environment we compensate for Cibicidoides- and Cibicides-specific offsets from equilibrium calcite of -0.35 and -0.55 ‰, respectively. After this taxon-specific adjustment, mean δ18OCib values plausibly reflect the density stratification of principle water masses in the Nordic Sea and Arctic Ocean. In addition, mean δ18OCib from AW not only significantly differs from mean δ18OCib from ABW, but also δ18OCib from within AW differentiates between provenience and water mass age. Furthermore, in shallow waters brine-derived low δ18Ow can significantly lower the δ18OCib of Cibicides spp. and thus δ18OCib may serve as a paleobrine indicator. There is no statistically significant difference, however, between deeper water masses mean δ18OCib of the Nordic Sea, and the Eurasian and Amerasian basins, and no influence of low-δ18Ow brines is recorded in Recent uABW and ABW δ18OCib of C. wuellerstorfi. This may be due to dilution of a low-δ18Ow brine signal in the deep sea, and/or to preferential incorporation of high-δ18Ow brines from high-salinity shelves. Although our data encompass environments with seasonal sea-ice and brine formation supposed to ultimately ventilate the deep Arctic Ocean, δ18OCib from uABW and ABW do not indicate negative excursions. This may challenge hypotheses that call for enhanced Arctic brine release to explain negative benthic δ18O spikes in deep-sea sediments from the late Pleistocene North Atlantic Ocean.
URI
http://repository.kopri.re.kr/handle/201206/7301
DOI
http://dx.doi.org/10.1016/j.marmicro.2014.09.002
Files in This Item
General Conditions
      ROMEO Green
    Can archive pre-print and post-print or publisher's version/PDF
      ROMEO Blue
    Can archive post-print (ie final draft post-refereeing) or publisher's version/PDF
      ROMEO Yellow
    Can archive pre-print (ie pre-refereeing)
      ROMEO White
    Archiving not formally supported

    qrcode

    Items in DSpace are protected by copyright, with all rights reserved, unless otherwise indicated.

    Browse