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Terminaciones de la edad de hielo
Hai Cheng1, R Lawrence Edwards, Wallace S Broecker
1Department of Geology and Geophysics, University of Minnesota, Minneapolis, MN 55455, USA.
Science (New York, N.Y.)
|October 10, 2009
Resumen
Los registros de precipitación del monzón asiático de las estalagmitas chinas se correlacionan con precisión con las terminaciones glaciales pasadas. Esto confirma la insolación de verano en el hemisferio norte como un disparador para el final de la edad de hielo, impactando el clima global y los niveles de CO2.
Área de la Ciencia:
- Paleoclimatología Paleoclimatología
- La geoquímica es la geoquímica.
- Ciencia Cuaternaria La ciencia cuaternaria es la ciencia cuaternaria.
Sus antecedentes:
- Comprender las terminaciones glaciales del pasado es crucial para predecir el cambio climático futuro.
- El monzón asiático (AM) juega un papel importante en la dinámica climática global.
- La correlación precisa de los registros paleoclimáticos es esencial para reconstruir eventos climáticos pasados.
Objetivo del estudio:
- Para caracterizar la precipitación del monzón asiático durante las edades de hielo pasadas utilizando registros de estalagmitas.
- Para correlacionar con precisión los registros de AM con otros archivos paleoclimáticos (núcleos de hielo, sedimentos marinos).
- Investigar los desencadenantes y mecanismos de las terminaciones glaciales.
Principales métodos:
- 230Th-fecha de las estalagmitas de la cueva de Sanbao, China.
- Análisis de los registros de isótopos de oxígeno de las estalagmitas.
- Correlación de los datos de estalagmitas con los registros de núcleos de hielo y sedimentos marinos.
Principales resultados:
- Los registros de isótopos de oxígeno de la Cueva de Sanbao proporcionan datos detallados de precipitación AM para las últimas cuatro terminaciones glaciales.
- Los registros de AM se correlacionan con precisión con los datos de núcleos de hielo y sedimentos marinos, estableciendo el momento del evento.
- Las observaciones apoyan la insolación de verano en el hemisferio norte como el desencadenante inicial del retroceso de la capa de hielo.
Conclusiones:
- Las terminaciones glaciales son iniciadas por la insolación de verano en el hemisferio norte.
- La afluencia de agua de deshielo en el Atlántico Norte altera la circulación oceánica y atmosférica, lo que afecta el clima global.
- El aumento del CO2 y la insolación impulsan la recesión de la capa de hielo, con posibles retroalimentaciones positivas entre el nivel del mar y el CO2.
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