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Sulfur Degassing From Steam‐Heated Crater Lakes: El Chichón (Chiapas, Mexico) and Víti (Iceland)
Author(s) -
Hasselle N.,
Rouwet D.,
Aiuppa A.,
JácomePaz M. P.,
Pfeffer M.,
Taran Y.,
Campion R.,
Bitetto M.,
Giudice G.,
Bergsson B.
Publication year - 2018
Publication title -
geophysical research letters
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 2.007
H-Index - 273
eISSN - 1944-8007
pISSN - 0094-8276
DOI - 10.1029/2018gl079012
Subject(s) - fumarole , impact crater , volcano , crater lake , sulfur , geology , atmosphere (unit) , volatiles , volcanic gases , geochemistry , environmental chemistry , mineralogy , environmental science , chemistry , geography , meteorology , physics , organic chemistry , astronomy
The composition of the gases released by El Chichón (Chiapas, Mexico) and Víti (Askja volcano, Iceland) volcanic lakes is examined by Multi‐GAS for the first time. Our results demonstrate that H 2 S and SO 2 are degassed by these pH 2–3 lakes. We find higher CO 2 /H 2 S and H 2 /H 2 S ratios in the lakes' emissions (31–5,685 and 0.6–35, respectively) than in the fumarolic gases feeding the lakes (13–33 and 0.08–0.5, respectively), evidencing that only a fraction (0.2–5.4% at El Chichón) of the H 2 S (g) contributed by the subaquatic fumaroles ultimately reaches the atmosphere. At El Chichón, we estimate a H 2 S output from the crater lake of 0.02–0.06 t/day. Curiously, SO 2 is also detected at trace levels in the gases released from both lakes (0.003–0.3 ppmv). We propose that H 2 S supplied into the lakes initiates a series of complex oxidation reactions, having sulfite as an intermediate product, and ultimately leading to SO 2 production and degassing.