Please use this identifier to cite or link to this item: http://hdl.handle.net/2445/175976
Title: Atmosphere-ocean linkages in the eastern equatorial Pacific over the early Pleistocene
Author: Povea de Castro, Patricia
Cacho Lascorz, Isabel
Moreno Caballud, Ana
Pena González, Leopoldo David
Menendez, Melisa
Calvo, Eva
Canals Artigas, Miquel
Robinson, Rebecca S.
Mendez, Fernando J.
Flores Villarejo, José Abel
Keywords: Paleoceanografia
Pacífic, Oceà
Plistocè
Paleoceanography
Pacific Ocean
Pleistocene
Issue Date: 1-May-2016
Publisher: American Geophysical Union (AGU)
Abstract: Here we present a new set of high-resolution early Pleistocene records from the eastern equatorial Pacific (EEP). Sediment composition from Ocean Drilling Program Sites 1240 and 1238 is used to reconstruct past changes in the atmosphere-ocean system. Particularly remarkable is the presence of laminated diatom oozes (LDOs) during glacial periods between 1.85 and 2.25Ma coinciding with high fluxes of opal and total organic carbon. Relatively low lithic particles (coarse and poorly sorted) and iron fluxes during these glacial periods indicate that the increased diatom productivity did not result from dust-stimulated fertilization events. We argue that glacial fertilization occurred through the advection of nutrient-rich waters from the Southern Ocean. In contrast, glacial periods after 1.85Ma are characterized by enhanced dust transport of finer lithic particles acting as a new source of nutrients in the EEP. The benthic ecosystem shows dissimilar responses to the high productivity recorded during glacial periods before and after 1.85Ma, which suggests that the transport processes delivering organic matter to the deep sea also changed. Different depositional processes are interpreted to be the result of two distinct glacial positions of the Intertropical Convergence Zone (ITCZ). Before 1.85Ma, the ITCZ was above the equator, with weak local winds and enhanced wet deposition of dust. After 1.85Ma, the glacial ITCZ was displaced northward, thus bringing stronger winds and stimulating upwelling in the EEP. The glacial period at 1.65Ma with the most intense LDOs supports a rapid southward migration of the ITCZ comparable to those glacial periods before 1.85Ma.
Note: Reproducció del document publicat a: https://doi.org/10.1002/2015PA002883
It is part of: Paleoceanography, 2016, vol. 31, num. 5, p. 522-538
URI: http://hdl.handle.net/2445/175976
Related resource: https://doi.org/10.1002/2015PA002883
ISSN: 0883-8305
Appears in Collections:Articles publicats en revistes (Dinàmica de la Terra i l'Oceà)

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