Evidence for tropical South Pacific climate change during the Younger Dryas and the Bolling-Allerod from geochemical records of fossil Tahiti corals

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doi: 10.1016/j.epsl.2009.09.011
Author(s): Asami, Ryuji; Felis, Thomas; Deschamps, Pierre; Hanawa, Kimio; Iryu, Yasufumi; Bard, Edouard; Durand, Nicolas; Murayama, Masafumi
Author Affiliation(s): Primary:
Tohoku University, Department of Geophysics, Sendai, Japan
University of Bremen, Federal Republic of Germany
Centre Européen de Recherche et d'Enseignement des Géosciences de l'Environnement, France
Nagoya University, Japan
Kochi University, Japan
Volume Title: Earth and Planetary Science Letters
Source: Earth and Planetary Science Letters, 288(1-2), p.96-107. Publisher: Elsevier, Amsterdam, Netherlands. ISSN: 0012-821X CODEN: EPSLA2
Note: In English. Supplemental information/data is available in the online version of this article. 37 refs.; illus., incl. 2 tables, sketch map
Summary: We present monthly resolved records of strontium/calcium (Sr/Ca) and oxygen isotope (δ18O) ratios from well-preserved fossil corals drilled during the Integrated Ocean Drilling Program (IODP) Expedition 310 "Tahiti Sea Level" and reconstruct sea surface conditions in the central tropical South Pacific Ocean during two time windows of the last deglaciation. The two Tahiti corals examined here are uranium/thorium (U/Th)-dated at 12.4 and 14.2 ka, which correspond to the Younger Dryas (YD) cold reversal and the Bolling-Allerod (B-A) warming of the Northern Hemisphere, respectively. The coral Sr/Ca records indicate that annual average sea surface temperature (SST) was 2.6-3.1°C lower at 12.4 ka and 1.0-1.6°C lower at 14.2 ka relative to the present, with no significant changes in the amplitude of the seasonal SST cycle. These cooler conditions were accompanied by seawater δ18O (δ18Osw) values higher by ≈0.8 ppm and ≈0.6 ppm relative to the present at 12.4 and 14.2 ka, respectively, implying more saline conditions in the surface waters. Along with previously published coral Sr/Ca records from the island [Cohen and Hart (2004), Deglacial sea surface temperatures of the western tropical Pacific: A new look at old coral. Paleoceanography 19, PA4031, doi:10.1029/2004PA001084], our new Tahiti coral records suggest that a shift toward lower SST by ≈1.5°C occurred from 13.1 to 12.4 ka, which was probably associated with a shift toward higher δ18Osw by ≈0.2 ppm. Along with a previously published coral Sr/Ca record from Vanuatu [Correge et al. (2004), Interdecadal variation in the extent of South Pacific tropical waters during the Younger Dyras event. Nature 428, 927-929], the Tahiti coral records provide new evidence for a pronounced cooling of the western to central tropical South Pacific during the Northern Hemisphere YD event. Abstract Copyright (2009) Elsevier, B.V.
Year of Publication: 2009
Research Program: IODP Integrated Ocean Drilling Program
Key Words: 24 Surficial Geology, Quaternary Geology; Absolute age; Alkaline earth metals; Allerod; Anthozoa; Bolling; Calcium; Cenozoic; Climate change; Cnidaria; Dates; Deglaciation; Diagenesis; East Pacific; Expedition 310; French Polynesia; Integrated Ocean Drilling Program; Invertebrata; Isotope ratios; Isotopes; Metals; O-18/O-16; Oceania; Oxygen; Pacific Ocean; Paleoclimatology; Pleistocene; Polynesia; Quaternary; Sea-level changes; Sea-surface temperature; Society Islands; South Pacific; Southeast Pacific; Sr/Ca; Stable isotopes; Strontium; Tahiti; Tahiti Sea Level Expedition; U/Pb; Upper Pleistocene; Upper Weichselian; Weichselian; Younger Dryas
Coordinates: S173000 S173000 W1491700 W1491700
Record ID: 2010038752
Copyright Information: GeoRef, Copyright 2019 American Geosciences Institute. Reference includes data from CAPCAS, Elsevier Scientific Publishers, Amsterdam, Netherlands