Open AccessMeasurements of 220 Rn and 222 Rn and CO 2 emissions in soil and fumarole gases on Mt. Etna volcano (Italy): Implications for gas transport and shallow ground fracture
Author(s) -
Giammanco S.,
Sims K. W. W.,
Neri M.
Publication year - 2007
Publication title -
geochemistry, geophysics, geosystems
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.928
H-Index - 136
ISSN - 1525-2027
DOI - 10.1029/2007gc001644
Subject(s) - fumarole , volcano , soil gas , geology , flux (metallurgy) , geochemistry , mineralogy , earth science , soil water , soil science , chemistry , organic chemistry
Measurements of 220 Rn and 222 Rn activity and of CO 2 flux in soil and fumaroles were carried out on Mount Etna volcano in 2005–2006, both in its summit area and along active faults on its flanks. We observe an empirical relationship between ( 220 Rn/ 222 Rn) and CO 2 efflux. The higher the flux of CO 2 , the lower the ratio between 220 Rn and 222 Rn. Deep sources of gas are characterized by high 222 Rn activity and high CO 2 efflux, whereas shallow sources are indicated by high 220 Rn activity and relatively low CO 2 efflux. Excess 220 Rn highlights sites of ongoing shallow rock fracturing that could be affected by collapse, as in the case of the rim of an active vent. Depletion both in 220 Rn and in CO 2 seems to be representative of residual degassing along recently active eruptive vents.