Oppenheimer C., Bani Philipson, Calkins J. A., Burton M. R., Sawyer G. M. (2006). Rapid FTIR sensing of volcanic gases released by Strombolian explosions at Yasur volcano, Vanuatu. Applied Physics B Lasers and Optics, 85 (2-3), p. 453-460. ISSN 0946-2171.
Titre du document
Rapid FTIR sensing of volcanic gases released by Strombolian explosions at Yasur volcano, Vanuatu
Oppenheimer C., Bani Philipson, Calkins J. A., Burton M. R., Sawyer G. M.
Source
Applied Physics B Lasers and Optics, 2006,
85 (2-3), p. 453-460 ISSN 0946-2171
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.
