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Rafting de hielo del Atlántico Norte: un cambio importante en 75.000 años antes del presente
Science (New York, N.Y.)
|June 10, 1977
Resumen
El eje principal de la deposición de las balsas de hielo se desplazó hacia el sur hace 75.000 años debido a la retirada de las aguas de deriva del Atlántico Norte. Este desplazamiento, impulsado por cambios de giros subpolares, probablemente se repitió en ciclos climáticos pasados.
Área de la Ciencia:
- Paleoclimatología Paleoclimatología
- Oceanografía La oceanografía es la oceanografía.
- Geología Geología Geología.
Sus antecedentes:
- El último ciclo climático de interglacial a glacial (127.000 a 10.000 años BP) fue el fue testigo de cambios paleoceanográficos significativos.
- Las deposiciones de balsas de hielo proporcionan evidencia crucial de las condiciones oceánicas y climáticas del pasado.
Objetivo del estudio:
- Investigar el desplazamiento en el eje primario de la deposición de las balsas de hielo durante el último ciclo glacial.
- Comprender los impulsores paleoceanográficos detrás de los cambios observados en los patrones de deposición.
Principales métodos:
- Análisis de núcleos de sedimentos para determinar la procedencia de las balsas de hielo y los patrones de deposición.
- Reconstrucción de la circulación oceánica pasada basada en proxies sedimentológicas e isotópicas.
Principales resultados:
- Un cambio geográfico fundamental en el depósito de las balsas de hielo se produjo alrededor de 75.000 años BP.
- El máximo deposicional migró de las costas de Groenlandia y Terranova a un eje zonal más al sur (40-50 grados N).
- Este desplazamiento se correlaciona con el retroceso de las cálidas aguas de deriva del Atlántico Norte.
Conclusiones:
- El flujo ciclónico en el giro subpolar explica ambos patrones de deposición.
- El retroceso de las aguas superficiales cálidas del giro noroccidental fue la causa principal del desplazamiento del eje de deposición.
- Es probable que se hayan producido cambios similares en la deposición de los balsas de hielo durante ciclos interglaciales-glaciales anteriores.
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