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Measuring Carbon-based Contaminant Mineralization Using Combined CO2 Flux and Radiocarbon Analyses
Published on: October 21, 2016
Marcado descenso en las concentraciones de dióxido de carbono atmosférico durante el Paleógeno
Mark Pagani1, James C Zachos, Katherine H Freeman
1Department of Geology and Geophysics, Yale University, 210 Whitney Avenue, New Haven, CT 06511, USA.
Science (New York, N.Y.)
|June 18, 2005
Resumen
Los niveles de dióxido de carbono (CO2) atmosférico eran altos en el Eoceno y disminuyeron gradualmente a través del Oligoceno, alcanzando los niveles modernos. Esta disminución de CO2 facilitó la expansión de la capa de hielo antártica y la evolución de la fotosíntesis del C4.
Área de la Ciencia:
- Paleoclimatología Paleoclimatología
- La paleoceanografía es la paleoceanografía.
- La geoquímica de los isótopos es la geoquímica de los isótopos.
Sus antecedentes:
- La relación entre el dióxido de carbono atmosférico (CO2) y el clima del Paleógeno sigue sin estar clara.
- Comprender los niveles pasados de CO2 es crucial para reconstruir la dinámica climática.
Objetivo del estudio:
- Para reconstruir los niveles de CO2 atmosférico durante el Eoceno medio hasta el Oligoceno tardío (hace 45 a 25 millones de años).
- Investigar el impacto de los cambios de CO2 en el clima y los ecosistemas del Paleógeno.
Principales métodos:
- Análisis de los valores isotópicos estables de carbono de las alquenonas di-insaturadas.
- Extracción de alquenonas de núcleos de sedimentos de aguas profundas.
Principales resultados:
- Los niveles de CO2 atmosférico oscilaron entre 1000 y 1500 partes por millón (ppm) en el Eoceno medio y tardío.
- El CO2 disminuyó en varias etapas a lo largo del Oligoceno, alcanzando los niveles modernos a finales del Oligoceno.
- La disminución observada de CO2 se correlacionó con la expansión de la capa de hielo de la Antártida y el surgimiento de la fotosíntesis C4.
Conclusiones:
- El clima del Paleógeno fue fuertemente influenciado por las fluctuaciones de CO2 a largo plazo.
- La transición Eoceno-Oligoceno marcó un cambio significativo en el sistema climático de la Tierra impulsado por la caída de CO2.
- Las tendencias de CO2 reconstruidas proporcionan un marco para comprender los principales cambios ambientales del Paleógeno.
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