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La inestabilidad a escala milenaria de la capa de hielo antártica durante la última glaciación
1Department of Geological Sciences, University of Florida, Gainesville, FL 32611, USA. Scripps Institution of Oceanography, University of California, San Diego, CA 92093, USA. Lawrence Livermore National Laboratory, Livermore, CA 9.
Science (New York, N.Y.)
|June 10, 2000
Resumen
Los eventos de inestabilidad de la capa de hielo antártica a escala milenaria, marcados por detritos de balsas de hielo, coincidieron con el calentamiento del Atlántico Norte y el aumento de la producción de aguas profundas. Estos episodios pueden haber desestabilizado las plataformas de hielo de la Antártida Occidental.
Área de la Ciencia:
- La paleoceanografía es la paleoceanografía.
- Ciencias del clima Ciencias del clima Ciencias del clima Ciencias del clima
- Glaciología glaciología.
Sus antecedentes:
- El detritus arrastrado por hielo (IRD) en núcleos de aguas profundas proporciona evidencia de la descarga de icebergs glaciales.
- La dinámica de la capa de hielo antártica (AIS) es crucial para el nivel global del mar y la circulación oceánica.
- La producción de aguas profundas del Atlántico Norte (NADW) es un componente clave de la circulación oceánica global y la regulación del clima.
Objetivo del estudio:
- Para investigar la relación entre la inestabilidad de la capa de hielo de la Antártida y la variabilidad del clima del Atlántico Norte durante el último período glacial.
- Para reconstruir patrones pasados de circulación de aguas profundas utilizando isótopos de carbono.
Principales métodos:
- Análisis de la concentración de detritos de balsas de hielo (IRD) en el sureste del Atlántico. núcleos de aguas profundas.
- Análisis de isótopos estables (isótopos de carbono, delta) de las foraminiferas bentónicas.
Principales resultados:
- Los pulsos a escala milenaria de entrega de IRD desde la Antártida ocurrieron hace entre 20.000 y 74.000 años.
- Las capas IRD se correlacionan a través de la Zona Frontal Polar, lo que indica una inestabilidad generalizada de la capa de hielo antártica.
- Los eventos IRD del Atlántico Sur coincidieron con el aumento de la producción de aguas profundas del Atlántico Norte (NADW) y el calentamiento del Atlántico Norte (interestadial).
Conclusiones:
- Los fuertes interestadios en el Atlántico Norte probablemente influyeron en la estabilidad de la capa de hielo de la Antártida.
- El aumento del nivel del mar o el aumento de la producción de NADW puede haber desestabilizado las plataformas de hielo de la Antártida Occidental, causando potencialmente un aumento en la región del mar de Weddell.
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