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Groenlandia estuvo casi libre de hielo durante largos períodos durante el Pleistoceno
Joerg M Schaefer1,2, Robert C Finkel1,3, Greg Balco4
1Lamont-Doherty Earth Observatory, Geochemistry, Palisades, New York 10964, USA.
Nature
|December 9, 2016
Resumen
La capa de hielo de Groenlandia (GIS) fue deglaciada durante largos períodos durante la época del Pleistoceno. Los nuevos datos de isótopos sugieren que el GIS era mucho más pequeño o ausente durante largos períodos de tiempo, desafiando los modelos de estabilidad anteriores.
Área de la Ciencia:
- Paleoclimatología
- Glaciología
- Geoquímica
Sus antecedentes:
- La estabilidad de la capa de hielo de Groenlandia (GIS) es crítica para los niveles globales del mar.
- La estabilidad del SIG en el pasado se debate debido a los limitados datos de proxy paleoclimáticos.
- Comprender la historia de los SIG es vital para predecir su respuesta al cambio climático.
Objetivo del estudio:
- Para reconstruir la paleoestabilidad de la capa de hielo de Groenlandia.
- Para investigar los períodos prolongados de deglaciación durante el Pleistoceno.
- Para conciliar la evidencia geológica con los modelos climáticos del SIG.
Principales métodos:
- Análisis de los isótopos de berilio-10 (10Be) y aluminio-26 (26Al) producidos por rayos cósmicos.
- Medición de isótopos en un núcleo de roca perforado cerca de la cumbre de GIS.
- Comparación de los datos isotópicos con los modelos de capa de hielo.
Principales resultados:
- La evidencia indica que Groenlandia fue deglaciada durante largos períodos durante la época del Pleistoceno.
- Los datos isotópicos sugieren que el SIG se redujo a menos del 10% de su volumen actual cuando el lecho rocoso estaba libre de hielo.
- El período de estabilidad GIS más largo es de 1,1 millones de años, posiblemente precedido por más de 280,000 años de condiciones libres de hielo.
Conclusiones:
- El GIS ha experimentado una deglaciación significativa y una ausencia casi completa durante el Pleistoceno.
- Los modelos climáticos existentes a menudo sobreestiman la estabilidad continua del SIG del Pleistoceno.
- Las futuras simulaciones de SIG deben incorporar períodos prolongados de condiciones libres de hielo bajo forzamientos climáticos pasados.
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