Mass-Independent Sulfur Isotopic Compositions in Stratospheric Volcanic Eruptions

Mélanie Baroni (1) , Mark H. Thiemens (2) , Robert Delmas (1) , Joël Savarino (1)

1 LGGE - Laboratoire de glaciologie et géophysique de l'environnement
2 Department of Chemistry and Biochemistry

The observed mass-independent sulfur isotopic composition (33S) of volcanic sulfate from the Agung (March 1963) and Pinatubo (June 1991) eruptions recorded in the Antarctic snow provides a mechanism for documenting stratospheric events. The sign of 33S changes over time from an initial positive component to a negative value. 33S is created during photochemical oxidation of sulfur dioxide to sulfuric acid on a monthly time scale, which indicates a fast process. The reproducibility of the results reveals that 33S is a reliable tracer to chemically identify atmospheric processes involved during stratospheric volcanism.

Domaines: Glaciologie; Volcanologie

Mélanie Baroni, Mark H. Thiemens, Robert Delmas, Joël Savarino. Mass-Independent Sulfur Isotopic Compositions in Stratospheric Volcanic Eruptions. Science, 2007, 315 (5808), pp.84 à 87. ⟨10.1126/science.1131754⟩. ⟨insu-00375891⟩