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La sincronización del último máximo glacial desde los mínimos observados al nivel del mar
Yokoyama1, Lambeck, De Deckker P
1Research School of Earth Sciences, The Australian National University, Canberra, ACT.
Nature
|August 30, 2000
Resumen
El Último Máximo Glacial vio enormes capas de hielo, superando a las actuales en 52,5 millones de kilómetros cúbicos. Este período terminó hace unos 19.000 años con una rápida disminución del 10% del volumen de hielo.
Área de la Ciencia:
- Paleoclimatología Paleoclimatología
- Glaciología glaciología.
- Geología marina Geología marina.
Sus antecedentes:
- El Último Máximo Glacial (LGM) se caracterizó por extensas capas de hielo y temperaturas globales más bajas.
- Las estimaciones directas del volumen de la capa de hielo LGM y la dinámica de fusión son escasas.
Objetivo del estudio:
- Para estimar el volumen máximo de hielo terrestre durante el LGM.
- Para determinar el momento de la fase de fusión inicial de las capas de hielo LGM.
- Para reconstruir los cambios en el nivel del mar y el balance de masa de la capa de hielo.
Principales métodos:
- Análisis de cuatro facies sedimentarias distintas en el Golfo Bonaparte, Australia.
- Identificación de las condiciones marinas y salobres utilizando ensamblajes faunísticos y preservación de sedimentos.
- La datación por radiocarbono y el modelado glacio-hidro-isostático para estimar el volumen y el tiempo del hielo.
Principales resultados:
- El volumen de hielo terrestre alcanzó su punto máximo entre 22.000 y 19.000 años calendario antes del presente.
- El volumen de hielo del LGM excedió las actuales capas de hielo a tierra en 52,5 x 10^6 km3.
- Una rápida reducción del 10% en el volumen de hielo hace unos 19.000 +/- 250 años marcó el final de la LGM.
Conclusiones:
- El Golfo Bonaparte proporciona un valioso registro para reconstruir la dinámica del hielo LGM.
- El LGM terminó con un evento de deglaciación significativo y relativamente rápido.
- Comprender el comportamiento pasado de las capas de hielo es crucial para predecir los impactos futuros del cambio climático.
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