%0 Journal Article
%9 ACL : Articles dans des revues avec comité de lecture répertoriées par l'AERES
%A Oppenheimer, C.
%A Bani, Philipson
%A Calkins, J. A.
%A Burton, M. R.
%A Sawyer, G. M.
%T Rapid FTIR sensing of volcanic gases released by Strombolian explosions at Yasur volcano, Vanuatu
%D 2006
%L fdi:010037621
%G ENG
%J Applied Physics B Lasers and Optics
%@ 0946-2171
%M CC:0002407249-0040
%N 2-3
%P 453-460
%R 10.1007/s00340-006-2353-4
%U https://www.documentation.ird.fr/hor/fdi:010037621
%> https://www.documentation.ird.fr/intranet/publi/2006/10/010037621.pdf
%V 85
%W Horizon (IRD)
%X We report here the results of a field campaign in which a portable Fourier transform infrared (FTIR) spectrometer was used to measure gas emissions from Yasur volcano, Vanuatu, in January 2005. By collecting FTIR spectra at a high rate (about 1 Hz), we were able to observe a marked difference in the proportions of SO2 and HCl in emissions released during Strombolian eruptions (SO2/HCl molar ratio up to similar to 30 or more) compared with the intervening passive emissions discharged from the magmatic vent (SO2/HCl similar to 2). This contrast can be explained by sourcing gas at different depths with respect to levels at which SO2 and HCl exsolve from the melt: deeper volatile exsolution supplies relatively SO2-rich gas responsible for the ephemeral explosions at the top of the conduit; while degassing of shallow magma, depleted in sulfur but rich in chlorine, contributes to the passive emission.
%$ 066