Monitoring so2 emission at the Soufriere Hills volcano: Implications for changes in eruptive conditions

S.R. Young; P.W. Francis; J. Barclay; T. J. Casadevall; C. A. Gardner; B. Darroux; M. A. Davies; P. Delmelle; G.E. Norton; A.J.H. Maciejewski; C.M.M. Oppenheimer; J. Stix; I.M. Watson

doi:10.1029/98gl01406

USGS · 70020276

Monitoring so2 emission at the Soufriere Hills volcano: Implications for changes in eruptive conditions

S.R. Young·P.W. Francis·J. Barclay·T. J. Casadevall·C. A. Gardner·B. Darroux·M. A. Davies·P. Delmelle·G.E. Norton·A.J.H. Maciejewski·C.M.M. Oppenheimer·J. Stix·I.M. Watson

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Abstract

Correlation spectrometer measurements of sulfur dioxide (SO 2 ) emission rates during the current eruption of the Soufriere Hills volcano, Montserrat, have contributed towards identifying different phases of volcanic activity. SO 2 emission rate has increased from <200 tonnes per day (td −1 ; <2.3 kgs −1 ) in the early stages of dome growth to >550 td −1 (>6.4 kgs −1 ) after July 1996, with the uncertainty associated with any individual measurement ca. 30%. Significantly enhanced SO 2 emission rates have been identified in association with early phreatic eruptions (800 td −1 (9.3 kgs −1 )) and episodes of vigorous dome collapse and pyroclastic flow generation (900 to 1500 td −1 (10.4 to 17.4 kgs −1 )). SO 2 emission rate has proved a useful proxy measurement for magma production rate. Observed SO 2 emission rates are significantly higher than those inferred from analyses of glass inclusions in phenocrysts, implying the existence of a S-rich magmatic vapour phase.

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S.R. Young, P.W. Francis, J. Barclay, T. J. Casadevall, C. A. Gardner, B. Darroux, M. A. Davies, P. Delmelle, G.E. Norton, A.J.H. Maciejewski, C.M.M. Oppenheimer, J. Stix, I.M. Watson. 1998. Monitoring so2 emission at the Soufriere Hills volcano: Implications for changes in eruptive conditions. https://doi.org/10.1029/98gl01406

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