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| Titel |
Equatorial Pacific peak in biological production regulated by nutrient and upwelling during the late Pliocene/early Pleistocene cooling |
| VerfasserIn |
J. Etourneau, R. S. Robinson, P. Martinez, R. Schneider |
| Medientyp |
Artikel
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| Sprache |
Englisch
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| ISSN |
1726-4170
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| Digitales Dokument |
URL |
| Erschienen |
In: Biogeosciences ; 10, no. 8 ; Nr. 10, no. 8 (2013-08-27), S.5663-5670 |
| Datensatznummer |
250085310
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| Publikation (Nr.) |
 copernicus.org/bg-10-5663-2013.pdf |
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| Zusammenfassung |
| The largest increase in export production in the eastern Pacific of the last
5.3 Myr (million years) occurred between 2.2 and 1.6 Myr, a time of major
climatic and oceanographic reorganization in the region. Here, we investigate
the causes of this event using reconstructions of export production, nutrient
supply and oceanic conditions across the Pliocene–Pleistocene in the eastern
equatorial Pacific (EEP) for the last 3.2 Myr. Our results indicate that the
export production peak corresponds to a cold interval marked by high nutrient
supply relative to consumption, as revealed by the low bulk sedimentary
15N/14N (δ15N) and alkenone-derived sea
surface temperature (SST) values. This ∼0.6 million year long episode
of enhanced delivery of nutrients to the surface of the EEP was predominantly
initiated through the upwelling of nutrient-enriched water sourced in high
latitudes. In addition, this phenomenon was likely promoted by the regional
intensification of upwelling in response to the development of intense Walker
and Hadley atmospheric circulations. Increased nutrient consumption in the
polar oceans and enhanced denitrification in the equatorial regions
restrained nutrient supply and availability and terminated the high export
production event. |
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