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Variations in hydrothermal methane and hydrogen concentrations following the 1998 eruption at Axial Volcano
Author(s) -
McLaughlinWest E. A.,
Olson E. J.,
Lilley M. D.,
Resing J. A.,
Lupton J. E.,
Baker E. T.,
Cowen J. P.
Publication year - 1999
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 - 10.1029/1999gl002336
Subject(s) - methane , hydrothermal circulation , hydrogen , volcano , plume , anaerobic oxidation of methane , mineralogy , geology , environmental chemistry , chemistry , geochemistry , meteorology , seismology , physics , organic chemistry
During the February response cruise to Axial Volcano, methane and hydrogen concentrations within the plume were significantly elevated above background. CH 4 /³He ratios were found to be 5–10 times greater than previously reported values for unsedimented ridges. An average δ 13 C value of −32.7±0.8‰ was determined for CH 4 concentrations >10 nM and CH 4 /Mn ratios were determined to be 2.2. Hydrogen concentrations as high as 183 nM were measured; however most were <10 nM. Microbial oxidation of methane was negligible (<0.001 day −1 ) during this sampling period. However, microbial hydrogen oxidation was sufficient to explain decreased H 2 concentrations measured at ‘older’ downstream stations.