Deglacial pattern of circulation and marine productivity in the upwelling region off central-south Chile

Mohtadi M.; Rossel P.; Lange, CB; Pantoja S.; Bóning P; Repeta, DJ; Grunwald M; Lamy, F; Hebbeln D.; Brumsack HJ

Abstract

A high-resolution sea surface temperature and paleoproductivity reconstruction on a sedimentary record collected at 36°S off central-south Chile (GeoB 7165-1, 36°33′S, 73°40′W, 797 m water depth, core length 750 cm) indicates that paleoceanographic conditions changed abruptly between 18 and 17 ka. Comparative analysis of several cores along the Chilean continental margin (30°-41°S) suggests that the onset and the pattern of deglacial warming was not uniform off central-south Chile due to the progressive southward migration of the Southern Westerlies and local variations in upwelling. Marine productivity augmented rather abruptly at 13-14 ka, well after the oceanographic changes. We suggest that the late deglacial increase in paleoproductivity off central-south Chile reflects the onset of an active upwelling system bringing nutrient-rich, oxygen-poor Equatorial Subsurface Water to the euphotic zone, and a relatively higher nutrient load of the Antarctic Circumpolar Current. During the Last Glacial Maximum, when the Southern Westerlies were located further north, productivity off central-south Chile, in contrast to off northern Chile, was reduced due to direct onshore-blowing winds that prevented coastal upwelling and export production. © 2008 Elsevier B.V. All rights reserved.

Más información

Título según WOS: Deglacial pattern of circulation and marine productivity in the upwelling region off central-south Chile
Título según SCOPUS: Deglacial pattern of circulation and marine productivity in the upwelling region off central-south Chile
Título de la Revista: EARTH AND PLANETARY SCIENCE LETTERS
Volumen: 272
Número: 01-feb
Editorial: Elsevier
Fecha de publicación: 2008
Página de inicio: 221
Página final: 230
Idioma: English
URL: http://linkinghub.elsevier.com/retrieve/pii/S0012821X0800294X
DOI:

10.1016/j.epsl.2008.04.043

Notas: ISI, SCOPUS