Skip navigation
SuUB logo
DSpace logo

  • Home
  • Institutions
    • University of Bremen
    • City University of Applied Sciences
    • Bremerhaven University of Applied Sciences
  • Sign on to:
    • My Media
    • Receive email
      updates
    • Edit Account details

Citation link: https://nbn-resolving.de/urn:nbn:de:gbv:46-ep000102121
00010212.pdf
OpenAccess
 
copyright

Reconstruction of surface ocean nitrate utilization in the Southeast Atlantic Ocean based on stable nitrogen isotopes.


File Description SizeFormat
00010212.pdf7.19 MBAdobe PDFView/Open
Authors: Holmes, M.E. 
Abstract: 
Stable nitrogen isotopes measured in bulk sediments and sinking particles have been used to evaluate changes in relative nutrient utilization in surface waters of the subtropical southeast Atlantic. In order to determine the dominant controls on the nitrogen isotopic composition of organic matter (OM) in this region at the present time, samples of sinking particulate matter collected with a sediment trap and surface sediments in seven sea to shore transects in the Angola and Cape Basins were analyzed. Variations in the degree of surface nitrate depletion during the Late Quaternary were also investigated based on g15N in two deep-sea cores from the Angola Basin.The g15N signal observed in sinking partic1es at the Walvis Ridge over a one year period mirrored sea surface temperatures (SST) and particulate flux rates with two distinct g15N decreases of ~2 in austral fall and spring. Low g15N values coincided with low SST, indicating that the low temperatures were brought about by recently upwelled, nutrient-rich water, a supposition substantiated by wind stress data from the literature. The simultaneous occurrance of maxima in particle flux rates with the decreases in g15N values and SST minima provides additional evidence that the g15N signal in sinking OM in the study area records the extent to which the surface nitrate pool has been utilized as well as the productivity variations driven by euphotic zone nitrate availability.
Issue Date: 1996
Journal/Edited collection: Berichte, Fachbereich Geowissenschaften, Universität Bremen 
Volume: 83
Pages: 113 pp
Type: Bericht, Report
ISSN: 0931-0800
Secondary publication: no
URN: urn:nbn:de:gbv:46-ep000102121
Institution: Universität Bremen 
Faculty: Fachbereich 05: Geowissenschaften (FB 05) 
Institute: Marum – Zentrum für Marine Umweltwissenschaften 
Appears in Collections:Forschungsdokumente

  

Page view(s)

533
checked on May 10, 2025

Download(s)

63
checked on May 10, 2025

Google ScholarTM

Check


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

Legal notice -Feedback -Data privacy
Media - Extension maintained and optimized by Logo 4SCIENCE