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Eruptive and diffuse emissions of CO2 from Mount Etna

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Patrick Allard at Paris Institute of Earth Physics
Patrick Allard
J. Carbonnelle
J. Carbonnelle
J. Carbonnelle
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D. Dajlevic
D. Dajlevic
D. Dajlevic
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J. Le Bronec
J. Le Bronec
J. Le Bronec
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Abstract

MOUNT Etna, in Sicily, is one of the world's most actively degassing volcanoes1. Here we use data collected from 1975 to 1987 to estimate carbon dioxide emissions from the summit craters and the upper flanks of the volcano. By combining measurements of the SO2 flux in the plume (refs 1–6 and this paper) with measurements of the CO2/SO2 ratio of the plume gases, we find that the average output of CO2 from summit crater degassing is 13±3 Tg yr−1. This is an order of magnitude higher than the annual CO2 output from Kilauea7,8, Hawaii, and representative arc volcanoes9,10. Furthermore, we find that diffuse emissions of CO2 from the upper flanks of Etna are magma-derived and are of a similar magnitude to those emitted from the crater plume. This observation, as well as others11–14, verifies the idea15 that extensive diffuse release of magmatic CO2 may occur in volcanically active regions—a process that needs to be taken into account when evaluating the volatile budget of subaerial volcanism. Such degassing may be of use for monitoring volcanic activity, could provide a means for radiocarbon dating of eruptions, and may be a mechanism by which CO2 is injected into crater lakes.
Allard et al Nature 351 1991 Eruptive and diffuse CO2 emissions from Mt Et
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Allard et al Nature 351 1991 Eruptive and diffuse CO2 emissions from Mt Et
na.pdf
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© 1991Nature Publishing Group
© 1991Nature Publishing Group
© 1991Nature Publishing Group
© 1991Nature Publishing Group
© 1991Nature Publishing Group
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... [1][2][3] Despite visible evidence of gas emissions, such as fumaroles, plumes, and thermal springs, other manifestations are detectable only with specific instrumentation, as is the case of diffuse degassing. 4,5 Diffuse degassing areas consist of permanent emission of gases, the predominant one being carbon dioxide (CO 2 ), with minor traces of hydrogen sulfide (H 2 S) and radon ( 222 Rn). These emissions are usually associated with tectonic structures, such as faults, which act as pathways for the gas ascent. ...
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... Much of the present-day knowledge about the degassing of natural systems comes from studies on persistently active volcanoes (e.g., Etna, Italy; e.g., Allard et al. 1991; abundant magmatic volatiles, together with sulfur dioxide (SO 2 ) (e.g., Symonds 1994). ...
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Mount Etna: The Anatomy of a Volcano
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Sulphur dioxide discharge from Mount Etna
Article
  • Aug 1977
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