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| Titel |
Oxygenation variability in Mejillones Bay, off northern Chile, during the last two centuries |
| VerfasserIn |
J. A. Díaz-Ochoa, S. Pantoja, G. J. Lange, C. B. Lange, G. E. Sánchez, V. R. Acuña, P. Muñoz, G. Vargas |
| 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 ; 8, no. 1 ; Nr. 8, no. 1 (2011-01-20), S.137-146 |
| Datensatznummer |
250005350
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| Publikation (Nr.) |
 copernicus.org/bg-8-137-2011.pdf |
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| Zusammenfassung |
| The Peru Chile Current ecosystem is characterized by high biological
productivity and important fisheries. Although this system is likely to be
severely affected by climate change, its response to current global warming
is still uncertain. In this paper, we analyze 10–166 year-old sediments in
two cores collected from Mejillones Bay, an anoxic sedimentary setting
favorable for the preservation of proxies. Based on a 166-year chronology,
we used proxies of bottom-water oxygenation (Mo, V, S, and the
(lycopane + n−C35)/n−C31 ratio) and surface water productivity
(biogenic opal, counts of diatom valves, biogenic Ba, organic carbon, and
chlorins) to reconstruct environmental variations in Mejillones Bay. During
the last two centuries, a shift took place in the coastal marine ecosystem
of Bahia Mejillones at decadal scales. This shift was characterized by
intense ENSO-like activity, large-scale fluctuations in biological export
productivity and bottom water oxygenation, and increased eolian activity
(inferred from Ti/Al and Zr/Al). This short-term variability was accompanied
by a gradual increase of sulfidic conditions that has intensified since the
early 1960s. |
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