The browser you are using is not supported by this website. All versions of Internet Explorer are no longer supported, either by us or Microsoft (read more here: https://www.microsoft.com/en-us/microsoft-365/windows/end-of-ie-support).

Please use a modern browser to fully experience our website, such as the newest versions of Edge, Chrome, Firefox or Safari etc.

Helena Filipsson, foto Erik Thor

Helena Filipsson

Professor

Helena Filipsson, foto Erik Thor

Pelagic-benthic coupling within an upwelling system of the subtropical northeast Atlantic over the last 35 ka BP

Author

  • Claire McKay
  • Helena Filipsson
  • O. E. Romero
  • J. -B. W. Stuut
  • B. Donner

Summary, in English

We present a high resolution, multiproxy study of the relationship between pelagic and benthic environments of a coastal upwelling system in the subtropical NE Atlantic Ocean. Marine sediments corresponding to late MIS3 to the Holocene in the radiocarbon dated core GeoB7926, retrieved off Mauritania (21 degrees N) were analysed to reconstruct productivity in surface waters and its linkage to deep waters during the last 35 ka BP. High latitude cold events and changes in atmospheric and oceanographic dynamics influenced upwelling intensity over this time period. Subsequently, this caused changes in primary productivity off this low-latitude coastal upwelling locality. The benthic foraminiferal fauna displays four main community shifts corresponding to fundamental climatic events, first of all during late MIS3 (35 28 ka BP), secondly from 28 to 19 ka BP (including Heinrich event 2 and the LGM), thirdly within Heinrich event 1, the Bolling Allerod and the Younger Diyas (18-11.5 ka BP) and finally during the Holocene (11.5-0 ka BP). In particular, strong pelagic benthic coupling is apparent in MIS 3, as demonstrated by increased primary productivity, indicated by moderate DAR and the dominance of benthic foraminiferal species which prefer fresh phytodetritus. A decline in upwelling intensity and nutrient availability follows, which resulted in a proportionately larger amount of older, degraded matter, provoking a shift in the benthic foraminifera fauna composition. This rapid response of the benthic environment continues with a progressive increase in upwelling intensity due to sea level and oceanographic changes and according high surface production during the LGM. During Heinrich event 1 and the Younger Dryas, extreme levels of primary production actually hindered benthic environment through the development of low oxygen conditions. After this period, a final change in benthic foraminiferal community composition occurs which indicates a return to more oxygenated conditions during the Holocene. (C) 2014 Elsevier Ltd. All rights reserved.

Department/s

  • Quaternary Sciences
  • StemTherapy: National Initiative on Stem Cells for Regenerative Therapy

Publishing year

2014

Language

English

Pages

299-315

Publication/Series

Quaternary Science Reviews

Volume

106

Document type

Journal article

Publisher

Elsevier

Topic

  • Geology

Keywords

  • Pelagic-benthic
  • Upwelling
  • Palaeoproductivity
  • Benthic foraminifera
  • Subtropical NE Atlantic

Status

Published

ISBN/ISSN/Other

  • ISSN: 0277-3791