Climate fluctuations during the Holocene in NW Iberia: high and low latitude linkages
L. D. Pena1, G. Francés2, P. Diz2, M. A. Nombela2, and I. Alejo21GRC Geociències Marines, Department de Estratigrafía, Paleontología i Geociències Marines, Universitat de Barcelona, C/ Martí i Franqués, s/n, 08028 Barcelona, Spain 2Departamento de Xeociencias Mariñas e Ordenación do Territorio, Facultade de Ciencias do Mar, Universidade de Vigo, As Lagoas-Marcosende, s/n, 36310 Vigo, Spain
Received: 13 Nov 2007 – Discussion started: 03 Dec 2007
Abstract. High resolution benthic foraminiferal oxygen and carbon stable isotopes (δ18O, δ13C) from core EUGC-3B are used here to infer rapid climatic changes for the last 8500 yr in the Ría de Muros (NW Iberian Margin). Benthic foraminiferal δ18O and δ13C potentially register migrations in the position of the hydrographic front formed between two different intermediate water masses: Eastern North Atlantic Central Water of subpolar origin (ENACWsp), and subtropical origin (ENACWsp). The isotopic records have been compared with two well established North Atlantic marine Holocene paleoceanographic records from low (Sea Surface Temperatures anomalies off Cape Blanc, NW Africa) and high latitudes (Hematite Stained Grains percentage, subpolar North Atlantic). This comparison clearly demonstrates that there is a strong link between high- and low-latitude climatic perturbations at centennial-millennial time scales during the Holocene. Spectral analyses also points at a pole-to-equator propagation of the so-called 1500 yr cycles. Our results demonstrate that during the Holocene, the NW Iberian Margin has undergone a series of cold episodes which are likely triggered at high latitudes in the North Atlantic and are rapidly propagated towards lower latitudes. Conceivably, the propagation of these rapid climatic changes involves a shift of atmospheric and oceanic circulatory systems and so a migration of the hydrographical fronts and water masses all along the North Atlantic area.
Pena, L. D., Francés, G., Diz, P., Nombela, M. A., and Alejo, I.: Climate fluctuations during the Holocene in NW Iberia: high and low latitude linkages, Clim. Past Discuss., 3, 1283-1309, doi:10.5194/cpd-3-1283-2007, 2007.