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Boron/Calcium ratio measured on Uvigerina spp. of sediment core PS75/103-1

Authors
Publisher
PANGAEA
Publication Date
Identifiers
DOI: 10.1594/pangaea.820660
Keywords
  • Ant-Xxvi/2
  • Awi_Paleo
  • Icp-Ms
  • Inductively Coupled Plasma - Mass Spectrometry
  • Paleoenvironmental Reconstructions From Marine Sediments @ Awi
  • Piston Corer (Bgr Type)
  • Polarstern
  • Ps75/103-1
  • Ps75 Bipomac
  • South Pacific Ocean
  • Uvigerina Spp
  • Boron/Calcium Ratio
  • Uvigerina Spp
  • Boron/Calcium Standard Deviation

Abstract

pa001868 1..15 Click Here for Full Article More humid interglacials in Ecuador during the past 500 kyr linked to latitudinal shifts of the equatorial front and the Intertropical Convergence Zone in the eastern tropical Pacific Daniel Rincón‐Martínez,1 Frank Lamy,1 Sergio Contreras,2 Guillaume Leduc,3 Edouard Bard,4 Cornelia Saukel,1 Thomas Blanz,3 Andreas Mackensen,1 and Ralf Tiedemann1 Received 8 October 2009; revised 10 February 2010; accepted 24 March 2010; published 2 June 2010. [1] Studying past changes in the eastern equatorial Pacific Ocean dynamics and their impact on precipitation on land gives us insight into how the Intertropical Convergence Zone (ITCZ) movements and the El Niño‐Southern Oscillation modulate regional and global climate. In this study we present a multiproxy record of terrigenous input from marine sediments collected off the Ecuadorian coast spanning the last 500 kyr. In parallel we estimate sea surface temperatures (SST) derived from alkenone paleothermometry for the sediments off the Ecuadorian coast and complement them with alkenone‐based SST data from the Panama Basin to the north in order to investigate SST gradients across the equatorial front. Near the equator, today’s river runoff is tightly linked to SST, reaching its maximum either during the austral summer when the ITCZ migrates southward or during El Niño events. Our multiproxy reconstruction of riverine runoff indicates that interglacial periods experienced more humid conditions than the glacial periods. The north‐south SST gradient is systematically steeper during glacial times, suggesting a mean background climatic state with a vigorous oceanic cold tongue, resembling modern La Niña conditions. This enhanced north‐south SST gradient would also imply a glacial northward shift of the Intertropical Convergence Zone at least in vicinity of the cold tongue: a pattern that has not yet been reproduced in climate models. Citation: Rincón‐Martínez, D., F. Lamy, S. Contreras, G. Leduc, E. Bard,

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