A new perspective of the Alboran Upwelling System reconstruction during the Marine Isotope Stage 11: A high-resolution coccolithophore record

QUATERNARY SCIENCE REVIEWS

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Article

Gonzalez-Lanchas, Alba¹  Flores, Jose-Abel¹  Sierro, Francisco J.¹  Angeles Barcena, Maria¹  Rigual-Hernandez, Andres S.¹  Oliveira, Dulce^2,3  Azibeiro, Lucia A.¹  Marino, Maria⁴  Maiorano, Patrizia⁴  Cortina, Aleix⁵  Cacho, Isabel⁶  Grimalt, Joan O.⁵ 

[1] Univ Salamanca, Dept Geol, Salamanca 37008, Spain

[2] Univ Algarve, Ctr Ciencias Mar CCMAR, Campus Gambelas, P-8005139 Faro, Portugal

[3] Inst Portugues Mar & Atmosfera IPMA, Div Geol & Georecursos Marinhos, Av Doutor Alfredo Magalhaes Ramalho 6, P-1495165 Alges, Portugal

[4] Univ Bari Aldo Moro, Dipartimento Sci Terra & Geoambientali, Bari, Italy

[5] IDAEA CSIC, Dept Environm Chem, Barcelona 08034, Spain

[6] Univ Barcelona, Fac Ciencies Terra, Dept Dinam Terra & Ocea, GRC Geociencies Marines, Barcelona 08028, Spain

关键词: Palaeoceanography;    Interglacial;    Marine isotope stage 11;    Alboran sea;    Western europe;    Micropaleontology;    Coccolithophore primary productivity;    North atlantic oscillation;   

DOI  :  10.1016/j.quascirev.2020.106520

来源: Elsevier

【 摘 要 】

A high-resolution study of the MIS 12/MIS 11 transition and the MIS 11 (430-376 kyr) coccolithophore assemblages at Ocean Drilling Program Site 977 was conducted to reconstruct the palaeoceanographic and climatic changes in the Alboran Sea from the variability in surface water conditions. The nannofossil record was integrated with the planktonic oxygen and carbon stable isotopes, as well as the U-37(k') Sea Surface Temperature (SST) at the studied site during the investigated interval. The coccolithophore primary productivity, reconstructed from the PPP (primary productivity proxy = absolute values of Gephyrocapsa caribbeanica + small Gephyrocapsa group) revealed pronounced fluctuations, that were strongly associated with variations in the intensity of the regional Alboran Upwelling System. The comparison of the nannoplankton record with opal phytolith content for the studied site and the already available pollen record at the nearby Integrated Ocean Drilling Program Site U1385, suggests an association of the upwelling dynamics with the variability of the North Atlantic Oscillation-like (NAO-like) phase. High PPP during positive (+) NAO-like phases is the result of intensified upwelling, owing to the complete development of the surface hydrological structures at the Alboran Sea. This scenario was identified during the MIS 12/MIS 11 transition (428-422 kyr), the late MIS 11c (405-397 kyr), and MIS11 b to MIS 11a (397-376 kyr). Two short-term minima in the PPP and SST were observed during MIS 11 b and were coeval with the North Atlantic Heinrich-type (Ht) events Ht3 (similar to 390 kyr) and Ht2 (similar to 384 kyr). Increased abundance of the subpolar Coccolithus pelagicus subsp. pelagicus and Gephyrocapsa muellerae was consistent with the inflow of cold surface waters into the Mediterranean Sea during the Ht events. Lowered PPP during negative (-) NAO-like phases is the result of moderate upwelling by the incomplete development of surface hydrological structures at the Alboran Sea. This scenario is expressed during the early MIS 11c (422-405 kyr). Overall, the results of our study provide evidence of the important role of atmospheric circulation patterns in the North Atlantic region for controlling phytoplankton primary production and oceanographic circulation dynamics in the Western Mediterranean during MIS 11. (C) 2020 Elsevier Ltd. All rights reserved.

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