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Terminación interhemisférica casi sincrónica del último máximo glacial en las latitudes medias
Joerg M Schaefer1, George H Denton, David J A Barrell
1Lamont-Doherty Earth Observatory (L-DEO), Palisades, NY 10964, USA. schaefer@ldeo.columbia.edu
Science (New York, N.Y.)
|June 10, 2006
Resumen
El calentamiento global al final de la última glaciación fue asíncrono, pero el retroceso de los glaciares de latitudes medias comenzó simultáneamente en ambos hemisferios. Esto sugiere que el aumento de las temperaturas globales estaba enmascarado por los fríos inviernos del Atlántico Norte.
Área de la Ciencia:
- Paleoclimatología Paleoclimatología
- Glaciología glaciología.
- Geocronología Geocronología.
Sus antecedentes:
- Los registros isotópicos de núcleos de hielo polar sugieren un calentamiento global asincrónico después de la última glaciación.
- Estudios anteriores indicaron diferentes plazos para la deglaciación en los hemisferios.
Objetivo del estudio:
- Para investigar el momento del retroceso de los glaciares de latitud media al final del último máximo glacial.
- Para conciliar el aparente calentamiento global asíncrono con el retroceso sincrónico de los glaciares.
Principales métodos:
- Se utilizó la exposición al 10Be (berilo-10) para la datación del retroceso de los glaciares.
- Se analizaron registros isotópicos de núcleos de hielo polar para datos de temperatura y CO2 atmosférico.
Principales resultados:
- La datación por exposición 10Be reveló un retroceso sincrónico a gran escala de los glaciares de latitudes medias en ambos hemisferios.
- El tiempo de retroceso de los glaciares se alinea con los datos de núcleos de hielo de la Antártida que muestran un aumento de la temperatura y el CO2.
- Las regiones del Atlántico Norte experimentaron inviernos hiperfríos debido al extenso hielo marino, lo que potencialmente oscurece las tendencias del calentamiento global.
Conclusiones:
- Las tendencias del calentamiento global al final del Último Máximo Glacial probablemente fueron enmascaradas en algunas regiones por anomalías climáticas localizadas.
- El retroceso sincrónico de los glaciares apoya un evento de calentamiento coordinado a nivel mundial, a pesar de las variaciones regionales.
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