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Un registro decadal de isótopos-clima de Europa central desde hace 15.500 a 5000 años antes de Cristo
von Grafenstein U1, Erlenkeuser, Brauer
1Laboratoire des Sciences du Climat et de l'Environnement (LSCE), F-91198 Gif-sur-Yvette, France. Leibniz-Labor fur Altersbestimmung und Isotopenforschung der Universitat Kiel, Germany. Laboratoire de Botanique Historique et Palynologie, Faculte d.
Science (New York, N.Y.)
|June 5, 1999
Resumen
Un lago alemán.
Área de la Ciencia:
- Paleoclimatología Paleoclimatología
- Geología Cuaternaria Geología Cuaternaria
- La geoquímica de los isótopos es la geoquímica de los isótopos.
Sus antecedentes:
- Los ostrácodos de los lagos profundos ofrecen un proxy de alta resolución para las precipitaciones pasadas.
- Las proporciones de isótopos de oxígeno (delta18OP) en los ostrácodos reflejan la variabilidad climática.
- Comprender los cambios climáticos pasados es crucial para predecir el cambio climático futuro.
Objetivo del estudio:
- Para reconstruir la variabilidad climática pasada utilizando delta18OP derivado del ostrácodo de Ammersee, Alemania.
- Para comparar el registro climático europeo con los datos del núcleo de hielo de Groenlandia.
- Investigar el papel de la circulación del Atlántico Norte durante la deglaciación.
Principales métodos:
- Análisis de las proporciones de isótopos de oxígeno en las conchas de ostrácodo de los sedimentos del Ammersee.
- Reconstrucción del clima con resolución decadal.
- Comparación con registros climáticos establecidos (por ejemplo, núcleos de hielo de Groenlandia).
Principales resultados:
- El registro del delta del Ammersee18OP revela cambios climáticos a escala decenal que reflejan los registros del núcleo de hielo de Groenlandia entre 15.000 y 5000 años BP.
- Las excursiones delta18OP negativas se correlacionan con eventos de circulación termohalina debilitados.
- Las tendencias a escala milenaria muestran cambios en los gradientes climáticos entre Europa y Groenlandia.
Conclusiones:
- Las descargas episódicas de agua dulce del Atlántico Norte probablemente causaron un debilitamiento a corto plazo de la circulación termohalina.
- El reordenamiento gradual de la circulación del Atlántico Norte influyó en los gradientes climáticos entre Europa y Groenlandia durante la deglaciación.
- Los avestruces de los lagos proporcionan un valioso archivo del clima terrestre para la paleoclimatología.
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