English   español  
Por favor, use este identificador para citar o enlazar a este item: http://hdl.handle.net/10261/18334
Compartir / Impacto:
Estadísticas
Add this article to your Mendeley library MendeleyBASE
Visualizar otros formatos: MARC | Dublin Core | RDF | ORE | MODS | METS | DIDL
Título

Submillennial-to-millennial variability of diatom production off Mauritania, NW Africa, during the last glacial cycle.

AutorRomero, Oscar E.; Kim, Jung-Hyun; Donner, Barbara
Palabras claveRapid climate change
Geochemical tracers
Micropaleontology
Sea surface temperature
Upwelling
Fecha de publicación12-sep-2008
EditorAmerican Geophysical Union
CitaciónPaleoceanography 23: 3218 (2008)
ResumenThe low-latitude upwelling regime off the Mauritanian coast in the subtropical NE Atlantic accounts for a significant part of global export production. Although productivity variations in coastal upwelling areas are usually attributed to changes in wind stress and upwelling intensity, productivity dynamics off Mauritania are less straightforward because of the complex atmospheric and hydrographic setting. Here we integrate micropaleontological (diatoms) and geochemical (bulk biogenic sediment components, X-ray fluorescence, and alkenones) proxies to examine on submillennial-to-millennial changes in diatom production that occurred off Mauritania, NW Africa, for the last 25 ka. During the Last Glacial Maximum (LGM, 19.0–23.0 ka B.P.), moderate silicate content of upwelled waters coupled with weakened NE trade winds determined moderate diatom productivity. No significant cooling is observed during the LGM, suggesting that our alkenone-based SST reconstruction represents a local, upwelling-related signal rather than a global insolation related one. Extraordinary increases in diatom and opal concentrations during Heinrich event 1 (H1, 15.5–18.0 ka B.P.) and the Younger Dryas (YD, 13.5–11.5 ka B.P.) are attributed to enhanced upwelling of silica-rich waters and an enlarged upwelling filament, due to more intense NE trade winds. The synchronous increase of CaCO3 and K intensity and the decreased opal and diatoms values mark the occurrence of the Bølling/Allerød (BA, 13.5–15.5 ka B.P.) due to weakened eolian input and more humid conditions on land. Although the high export of diatoms is inextricably linked to upwelling intensity off Mauritania, variability in the nutrient content of the thermocline also plays a decisive role.
Versión del editorhttp://dx.doi.org/10.1029/2008PA001601
URIhttp://hdl.handle.net/10261/18334
DOI10.1029/2008PA001601
ISSN0883-8305
Aparece en las colecciones: (IACT) Artículos
Ficheros en este ítem:
No hay ficheros asociados a este ítem.
Mostrar el registro completo
 

Artículos relacionados:


NOTA: Los ítems de Digital.CSIC están protegidos por copyright, con todos los derechos reservados, a menos que se indique lo contrario.