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Intensificación del flujo de entrada y ventilación del Pacífico profundo en épocas glaciales del Pleistoceno

I R Hall¹, I N McCave, N J Shackleton

¹Department of Earth Sciences, Cardiff University, PO Box 914, Cardiff CF10 3YE, UK. Hall@cardiff.ac.uk

|August 24, 2001

Resumen

La producción de aguas profundas del Océano Antártico tiene un impacto significativo en el presupuesto de calor de la Tierra. Los períodos glaciales vieron una intensificación de la afluencia profunda del Pacífico, probablemente debido al aumento de la formación de agua de fondo antártica.

Área de la Ciencia:

* La paleoceanografía
* Ciencias del clima Ciencias del clima
* La Dinámica del Océano Austral

Sus antecedentes:

* La producción de aguas profundas del Océano Austral influye en la distribución global del calor.
* El suministro de agua profunda al Océano Pacífico proviene principalmente de la corriente de frontera occidental profunda al este de Nueva Zelanda.

Objetivo del estudio:

* Reconstruir las propiedades de las aguas profundas y los cambios de velocidad de flujo en el Océano Pacífico durante la época del Pleistoceno.
* Investigar la relación entre la afluencia profunda del Pacífico y la producción de agua de fondo de la Antártida.

Principales métodos:

* Análisis de núcleos de sedimentos influenciados por la corriente de la frontera occidental profunda.
* Aplicación de proxies físicos e isotópicos para reconstruir las condiciones pasadas de aguas profundas.

Principales resultados:

* Evidencia de intensificación de la entrada y ventilación del océano Pacífico profundo durante los períodos glaciales en los últimos 1,2 millones de años.
* Los cambios observados en el flujo de las aguas profundas se correlacionan con el aumento de la producción de agua de fondo antártica durante las épocas glaciales.
* Se identificaron perturbaciones significativas en la circulación termohalina global durante la transición climática del Pleistoceno medio (hace 0,86 a 0,45 millones de años).

Conclusiones:

* La intensificación de la afluencia profunda del Pacífico durante los períodos glaciales puede ser impulsada por el aumento de los vientos del Océano Antártico o la formación de hielo marino.
* La producción de agua de fondo antártico es un factor clave en la regulación de la circulación profunda del Pacífico.
* La transición climática de mediados del Pleistoceno marcó un cambio significativo en los patrones de circulación oceánica global.

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