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Composiciones isotópicas de azufre independientes de la masa en las erupciones volcánicas estratosféricas
Mélanie Baroni1, Mark H Thiemens, Robert J Delmas
1Laboratoire de Glaciologie et Géophysique de l'Environnement, CNRS/Université Joseph Fourier, 38400 St. Martin d'Hères, France. baroni@lgge.obs.ujf-grenoble.fr
Science (New York, N.Y.)
|January 6, 2007
Resumen
Los isótopos de azufre independientes de la masa (Delta33S) en la nieve de la Antártida revelan eventos estratosféricos volcánicos. Este rastreador fiable rastrea la rápida oxidación fotoquímica de dióxido de azufre a lo largo del tiempo.
Área de la Ciencia:
- La geoquímica es la geoquímica.
- Ciencias de la atmósfera Ciencias atmosféricas.
- La geoquímica de los isótopos es la geoquímica de los isótopos.
Sus antecedentes:
- Las erupciones volcánicas inyectan dióxido de azufre en la estratosfera, influyendo en la química atmosférica.
- Los isótopos de azufre, en particular la fraccionamiento independiente de la masa (Delta33S), ofrecen información sobre los procesos atmosféricos.
Objetivo del estudio:
- Para investigar la utilidad de Delta33S en la nieve antártica como un rastreador de eventos volcánicos estratosféricos.
- Comprender la escala de tiempo y el mecanismo de la formación de Delta33S durante la evolución del penacho volcánico.
Principales métodos:
- Análisis del sulfato volcánico en las capas de nieve de la Antártida.
- Medición de la composición isotópica del azufre, específicamente Delta33S.
Principales resultados:
- Se observaron señales Delta33S de las erupciones de Agung (1963) y Pinatubo (1991) en la nieve antártica.
- Se demostró un cambio temporal en el signo Delta33S de positivo a negativo.
- Indicado la formación rápida de Delta33S en una escala de tiempo mensual a través de la oxidación fotoquímica de dióxido de azufre a ácido sulfúrico.
Conclusiones:
- Delta33S en la nieve antártica es un rastreador confiable para documentar los eventos volcánicos estratosféricos.
- Las variaciones observadas de Delta33S confirman rápidos procesos fotoquímicos atmosféricos.
- Los resultados reproducibles de Delta33S validan su uso en la identificación de procesos atmosféricos volcánicos.
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