Application and quality of X-Ray fluorescence core scanning in reconstructing late Pleistocene NW African continental margin sedimentation patterns and paleoclimate variations

Abrupt climate changes during the last glacial-interglacial cycle known as Dansgaard-Oeschger (D-O) oscillations. Although, it is evident that these climate changes are most severe in the North Atlantic realm, the forcing of the D-O climate oscillations is still controversial. Feedback mechanisms be...

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Main Author: Tjallingii, Rik
Other Authors: Wefer, Gerold, Bickert, Torsten, Röhl, Ursula, Stein, Rüdiger
Format: Doctoral or Postdoctoral Thesis
Language:English
Published: Universität Bremen 2007
Subjects:
550
Online Access:https://media.suub.uni-bremen.de/handle/elib/2348
https://nbn-resolving.org/urn:nbn:de:gbv:46-diss000106647
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spelling ftsubbremen:oai:media.suub.uni-bremen.de:Publications/elib/2348 2023-05-15T16:30:28+02:00 Application and quality of X-Ray fluorescence core scanning in reconstructing late Pleistocene NW African continental margin sedimentation patterns and paleoclimate variations Anwendungen und Qualitätsbeurteilung von XRF-Analysen zur Rekonstruktion spät-Pleistozäner Sedimentations- und Klima-Änderungen am NW Afrikanischen Kontinentalrand Tjallingii, Rik Wefer, Gerold Bickert, Torsten Röhl, Ursula Stein, Rüdiger 2007-02-12 application/pdf https://media.suub.uni-bremen.de/handle/elib/2348 https://nbn-resolving.org/urn:nbn:de:gbv:46-diss000106647 eng eng Universität Bremen FB5 Geowissenschaften https://media.suub.uni-bremen.de/handle/elib/2348 urn:nbn:de:gbv:46-diss000106647 info:eu-repo/semantics/openAccess Alle Rechte vorbehalten NW Africa Cape Blanc XRF core scanner end member modeling eolian dust aridity vegetation cover productivity upwelling 550 550 Earth sciences and geology ddc:550 Dissertation doctoralThesis 2007 ftsubbremen 2022-12-18T23:09:13Z Abrupt climate changes during the last glacial-interglacial cycle known as Dansgaard-Oeschger (D-O) oscillations. Although, it is evident that these climate changes are most severe in the North Atlantic realm, the forcing of the D-O climate oscillations is still controversial. Feedback mechanisms between ocean heat transport, atmospheric circulation, and low latitude climate changes are thought to play an important role in the continuation, amplification, and possibly initiation of D-O climate oscillations. However, the role low-latitude climate zones and their potential to influence or initiate high-latitude climate change is still unknown. The region off Cape Blanc (Northwest Africa) is situated between the North Atlantic mid latitudes and the equatorial Atlantic, and is a key region to study climate forcing in the subtropics.Millennial-scale changes of the terrigenous sediment composition based on non-destructive XRF core scanning and grain-size variations of the terrigenous sediment fraction indicate coherent high- and low- climate variations during the last glacial-interglacial cycle. Water corrected X-Ray Fluorescence (XRF) Core Scanner measurements are used to obtaining chemical changes of the eolian dust input. End member modeling of the terrigenous fraction reveal two eolian end members, and a hemipelagic end member. Additionally, opal and organic matter accumulations are used to reconstruct upwelling intensities and surface water productivity off Cape Blanc. These data indicate increased continental aridity, trade wind intensities, and upwelling intensities accompanied by reduced surface water productivity associated with North Atlantic Heinrich events and extreme Greenland stadial events. Moreover, both the eolian contributions off Cape Blanc and simulations of the vegetation (obtained from the Atmosphere-Ocean-Vegetation model CLIMBER 2) indicate that Northwest African humidity is forced by the strength of the African Monsoon during interglacial conditions. Doctoral or Postdoctoral Thesis Greenland North Atlantic Media SuUB Bremen (Staats- und Universitätsbibliothek Bremen) Greenland
institution Open Polar
collection Media SuUB Bremen (Staats- und Universitätsbibliothek Bremen)
op_collection_id ftsubbremen
language English
topic NW Africa
Cape Blanc
XRF core scanner
end member modeling
eolian dust
aridity
vegetation cover
productivity
upwelling
550
550 Earth sciences and geology
ddc:550
spellingShingle NW Africa
Cape Blanc
XRF core scanner
end member modeling
eolian dust
aridity
vegetation cover
productivity
upwelling
550
550 Earth sciences and geology
ddc:550
Tjallingii, Rik
Application and quality of X-Ray fluorescence core scanning in reconstructing late Pleistocene NW African continental margin sedimentation patterns and paleoclimate variations
topic_facet NW Africa
Cape Blanc
XRF core scanner
end member modeling
eolian dust
aridity
vegetation cover
productivity
upwelling
550
550 Earth sciences and geology
ddc:550
description Abrupt climate changes during the last glacial-interglacial cycle known as Dansgaard-Oeschger (D-O) oscillations. Although, it is evident that these climate changes are most severe in the North Atlantic realm, the forcing of the D-O climate oscillations is still controversial. Feedback mechanisms between ocean heat transport, atmospheric circulation, and low latitude climate changes are thought to play an important role in the continuation, amplification, and possibly initiation of D-O climate oscillations. However, the role low-latitude climate zones and their potential to influence or initiate high-latitude climate change is still unknown. The region off Cape Blanc (Northwest Africa) is situated between the North Atlantic mid latitudes and the equatorial Atlantic, and is a key region to study climate forcing in the subtropics.Millennial-scale changes of the terrigenous sediment composition based on non-destructive XRF core scanning and grain-size variations of the terrigenous sediment fraction indicate coherent high- and low- climate variations during the last glacial-interglacial cycle. Water corrected X-Ray Fluorescence (XRF) Core Scanner measurements are used to obtaining chemical changes of the eolian dust input. End member modeling of the terrigenous fraction reveal two eolian end members, and a hemipelagic end member. Additionally, opal and organic matter accumulations are used to reconstruct upwelling intensities and surface water productivity off Cape Blanc. These data indicate increased continental aridity, trade wind intensities, and upwelling intensities accompanied by reduced surface water productivity associated with North Atlantic Heinrich events and extreme Greenland stadial events. Moreover, both the eolian contributions off Cape Blanc and simulations of the vegetation (obtained from the Atmosphere-Ocean-Vegetation model CLIMBER 2) indicate that Northwest African humidity is forced by the strength of the African Monsoon during interglacial conditions.
author2 Wefer, Gerold
Bickert, Torsten
Röhl, Ursula
Stein, Rüdiger
format Doctoral or Postdoctoral Thesis
author Tjallingii, Rik
author_facet Tjallingii, Rik
author_sort Tjallingii, Rik
title Application and quality of X-Ray fluorescence core scanning in reconstructing late Pleistocene NW African continental margin sedimentation patterns and paleoclimate variations
title_short Application and quality of X-Ray fluorescence core scanning in reconstructing late Pleistocene NW African continental margin sedimentation patterns and paleoclimate variations
title_full Application and quality of X-Ray fluorescence core scanning in reconstructing late Pleistocene NW African continental margin sedimentation patterns and paleoclimate variations
title_fullStr Application and quality of X-Ray fluorescence core scanning in reconstructing late Pleistocene NW African continental margin sedimentation patterns and paleoclimate variations
title_full_unstemmed Application and quality of X-Ray fluorescence core scanning in reconstructing late Pleistocene NW African continental margin sedimentation patterns and paleoclimate variations
title_sort application and quality of x-ray fluorescence core scanning in reconstructing late pleistocene nw african continental margin sedimentation patterns and paleoclimate variations
publisher Universität Bremen
publishDate 2007
url https://media.suub.uni-bremen.de/handle/elib/2348
https://nbn-resolving.org/urn:nbn:de:gbv:46-diss000106647
geographic Greenland
geographic_facet Greenland
genre Greenland
North Atlantic
genre_facet Greenland
North Atlantic
op_relation https://media.suub.uni-bremen.de/handle/elib/2348
urn:nbn:de:gbv:46-diss000106647
op_rights info:eu-repo/semantics/openAccess
Alle Rechte vorbehalten
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