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A stalagmite test of North Atlantic SST and Iberian hydroclimate linkages over the last two glacial cycles
Climate of the Past
  • Rhawn F. Denniston, Cornell College
  • Amanda N. Houts, Cornell College
  • Yemane Asmerom, University of New Mexico
  • Alan D. Wanamaker, Jr., Iowa State University
  • Jonathan A. Haws, University of Louisville
  • Victor J. Polyak, University of New Mexico
  • Diana L. Thatcher, Iowa State University
  • Setsen Altan-Ochir, Cornell College
  • Alyssa C. Borowske, Cornell College
  • Sebastian F. M. Breitenbach, Ruhr-University
  • Caroline C. Ummenhofer, Woods Hole Oceanographic Institution
  • Frederico T. Regala, Associação de Estudos Subterrâneos e Defesa do Ambiente
  • Michael M. Benedetti, University of North Carolina at Wilmington
  • Nuno F. Bicho, Universidade do Algarve
Document Type
Article
Publication Version
Published Version
Publication Date
1-1-2018
DOI
10.5194/cp-14-1893-2018
Abstract

Close coupling of Iberian hydroclimate and North Atlantic sea surface temperature (SST) during recent glacial periods has been identified through the analysis of marine sediment and pollen grains co-deposited on the Portuguese continental margin. While offering precisely correlatable records, these time series have lacked a directly dated, site-specific record of continental Iberian climate spanning multiple glacial cycles as a point of comparison. Here we present a high-resolution, multi-proxy (growth dynamics and δ13C, δ18O, and δ234U values) composite stalagmite record of hydroclimate from two caves in western Portugal across the majority of the last two glacial cycles (∼220 ka). At orbital and millennial scales, stalagmite-based proxies for hydroclimate proxies covaried with SST, with elevated δ13C, δ18O, and δ234Uvalues and/or growth hiatuses indicating reduced effective moisture coincident with periods of lowered SST during major ice-rafted debris events, in agreement with changes in palynological reconstructions of continental climate. While in many cases the Portuguese stalagmite record can be scaled to SST, in some intervals the magnitudes of stalagmite isotopic shifts, and possibly hydroclimate, appear to have been somewhat decoupled from SST.

Comments

This article is published as Denniston, R. F., Houts, A. N., Asmerom, Y., Wanamaker Jr., A. D., Haws, J. A., Polyak, V. J., Thatcher, D. L., Altan-Ochir, S., Borowske, A. C., Breitenbach, S. F. M., Ummenhofer, C. C., Regala, F. T., Benedetti, M. M., and Bicho, N. F.: A stalagmite test of North Atlantic SST and Iberian hydroclimate linkages over the last two glacial cycles, Clim. Past, 14 (2018): 1893-1913, doi: 10.5194/cp-14-1893-2018.

Creative Commons License
Creative Commons Attribution 4.0 International
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Language
en
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application/pdf
Citation Information
Rhawn F. Denniston, Amanda N. Houts, Yemane Asmerom, Alan D. Wanamaker, et al.. "A stalagmite test of North Atlantic SST and Iberian hydroclimate linkages over the last two glacial cycles" Climate of the Past Vol. 14 (2018) p. 1893 - 1913
Available at: http://works.bepress.com/alan-wanamaker/16/