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Variation of H2O/CO2 and CO2/SO2 ratios of volcanic gases discharged by continuous degassing of Mount Etna volcano, Italy
Author(s)
Language
English
Obiettivo Specifico
1.2. TTC - Sorveglianza geochimica delle aree vulcaniche attive
4.5. Degassamento naturale
Status
Published
JCR Journal
JCR Journal
Peer review journal
Yes
Title of the book
Issue/vol(year)
/113 (2008)
Publisher
American Geophysical Union
Pages (printed)
B09203
Issued date
September 5, 2008
Alternative Location
Abstract
We applied the Multi-GAS technique to measure compositions of the volcanic plumes
continuously discharged from summit craters of Voragine, Northeast and Bocca Nuova at
Mount Etna, in an attempt to estimate compositions of the source volcanic gases. The
estimated CO2/SO2 and H2O/CO2 ratios of the volcanic gases show a large variation
ranging from 0.6 to 30 and from 1 to 18, respectively. This variability overlaps with the
compositional range of dissolved volatiles in melt inclusions and their coexisting bubbles in
a magma chamber and can be caused by the low-pressure degassing of a magma with
variable bubble content ranging from 0.3 to 15 wt.%. The variable bubble content in the
magma is likely a result of supply of deep-derived CO2-rich gas phase to the chamber and
subsequent bubble-magma differentiation by bubble ascent in the magma chamber. In
contrast, the variation of volcanic gas composition can also be caused by changes of
degassing pressure (gas–magma separation pressure), ranging from 0 to 100 MPa, as a
result of changes in the depth of the top of the convecting magma in volcanic conduits. Both
mechanisms can cause similar compositional variations. However, the two mechanisms
will result in contrasting correlations between the SO2 emission rates and the gas
compositions that can be examined by parallel observations of the emission rates and
compositions in the future.
continuously discharged from summit craters of Voragine, Northeast and Bocca Nuova at
Mount Etna, in an attempt to estimate compositions of the source volcanic gases. The
estimated CO2/SO2 and H2O/CO2 ratios of the volcanic gases show a large variation
ranging from 0.6 to 30 and from 1 to 18, respectively. This variability overlaps with the
compositional range of dissolved volatiles in melt inclusions and their coexisting bubbles in
a magma chamber and can be caused by the low-pressure degassing of a magma with
variable bubble content ranging from 0.3 to 15 wt.%. The variable bubble content in the
magma is likely a result of supply of deep-derived CO2-rich gas phase to the chamber and
subsequent bubble-magma differentiation by bubble ascent in the magma chamber. In
contrast, the variation of volcanic gas composition can also be caused by changes of
degassing pressure (gas–magma separation pressure), ranging from 0 to 100 MPa, as a
result of changes in the depth of the top of the convecting magma in volcanic conduits. Both
mechanisms can cause similar compositional variations. However, the two mechanisms
will result in contrasting correlations between the SO2 emission rates and the gas
compositions that can be examined by parallel observations of the emission rates and
compositions in the future.
References
Aiuppa, A., C. Federico, A. Paonita, G. Giudice, and M. Valenza (2002),
S, Cl and F degassing as an indicator of volcanic dynamics: The 2001
eruption of Mount Etna, Geophys. Res. Lett., 29(11), 1556, doi:10.1029/
2002GL015032.
Aiuppa, A., C. Federico, G. Giudice, and S. Gurrieri (2005a), Chemical
mapping of a fumarolic field: La Fossa Crater, Vulcano Island (Aeolian
Islands, Italy), Geophys. Res. Lett., 13, L13309, doi:10.1029/
2005GL023207.
Aiuppa,A., S. Inguaggiato,A. J. S.McGonigle, M.O’Dwyer, C.Oppenheimer,
M. J. Padgett, D. Rouwet, and M. Valenza (2005b), H2S fluxes from
Mt. Etna, Stromboli, and Vulcano (Italy) and implications for the sulfur
budget at volcanoes, Geochim. Cosmochim. Acta, 69, 1861– 1871.
Aiuppa, A., C. Federico, G. Giudice, S. Gurrieri, M. Liuzzo, H. Shinohara,
R. Favara, and M. Valenza (2006), Rates of carbon dioxide plume degassing
from Mount Etna volcano, J. Geophys. Res., 111, B09207,
doi:10.1029/2006JB004307.
Aiuppa, A., R. Moretti, C. Federico, G. Giudice, S. Gurrieri, M. Liuzzo,
P. Papale, H. Shinohara, and M. Valenza (2007), Forecasting Etna
eruption by real-time observation of volcanic gas composition, Geology,
35, 1115– 1118.
Allard, P. (1997), Endogenous magma degassing and storage at Mount
Etna, Geophys. Res. Lett., 24, 2219– 2222.
Allard, P., B. Behncke, S. D’Amico, M. Neri, and S. Gambino (2006),
Mount Etna 1993– 2005: Anatomy of an evolving eruptive cycle, Earth
Sci. Rev., 78, 85– 114.
Allard, P., et al. (1991), Eruptive and diffuse emissions of CO2 from Mount
Etna, Nature, 351, 387– 391.
Allard, P., M. Burton, and F. Mure` (2005), Spectroscopic evidence for a
lava fountain driven by previously accumulated magmatic gases, Nature,
433, 407–410.
Andres, R. J., and A. D. Kasgnoc (1998), A time-averaged inventory of
subaerial volcanic sulfur emissions, J. Geophys. Res., 103, 25,251 –
25,261.
Burton, M. R., C. Oppenheimer, L. A. Horrocks, and P. W. Francis (2000),
Remote sensing of CO2 and H2O emission rates from Masaya volcano,
Nicaragua, Geology, 28, 915– 918.
Burton, M. R., P. Allard, F. Mure`, and C. Oppenheimer (2003), FTIR
remote sensing of fractional magma degassing at Mount Etna, Sicily, in
Volcanic Degassing, edited by C. Oppenheimer, D. Pyle, and J. Barclay,
Geol. Soc. London Spec. Pub., 213, 281–293.
Caltabiano, T., M. Burton, S. Giammanco, P. Allard, N. Bruno, F. Mure`,
and R. Romano (2004), Volcanic Gas Emissions from the Summit Craters
and Flanks of Mt. Etna, 1987–2000 in Mt. Etna: Volcano Laboratory,
Geophys. Monogr. Ser., vol. 143, edited by A. Bonaccorso et al., AGU,
Washington D. C.
Carroll, M. R., and J. D. Webster (1994), Solubilities of sulfur, noble gases,
nitrogen, chlorine and fluorine in magmas, in Volatiles in Magmas, edited
by M. R. Carroll and J. R. Holloway, Rev. Mineral., 30, 231– 279.
Chiodini, G., R. Cioni, L. Marini, and C. Panichi (1995), Origin of the
fumarolic fluids of Vulcano Island, Italy and implications for volcanic
surveillance, Bull. Volcanol., 57, 99– 110.
Eichelberger, J. C., C. R. Carrigan, H. R. Westrich, and J. R. Shannon
(1986), Non-explosive volcanism, Nature, 323, 598– 602.
Gerlach, T. M. (1991), Present-day CO2 emissions from volcanoes, Eos
Trans. AGU, 72, 240– 253.
Giggenbach, W. F. (1996), Chemical composition of volcanic gases, in
Monitoring and Mitigation of Volcanic Hazards, edited by R. Scarpa
and R. I. Tilling, Springer Verlag, Berlin-Heidelberg.
Giggenbach, W. F., and F. Le Guern (1976), The chemistry of magmatic
gases from Erta’Ale, Ethiopia, Geochim. Cosmochim. Acta, 40, 25– 30.
Giggenbach, W. F., and S. Matsuo (1991), Evaluation of results from second
and Third IAVCEI Field Workshop on Volcanic Gases, Mt. Usu,
Japan and White Island, N. Z. Appl. Geochem., 6, 125– 141.
Giggenbach, W. F., and D. S. Sheppard (1989), Variation in the temperature
and chemistry of White Island fumarole discharges 1972– 85, N. Z. Geol.
Surv. Bull., 103, 119–126.
Kazahaya, K., H. Shinohara, and G. Saito (1994), Excessive degassing of
Izu-Oshima volcano: Magma convection in a conduit, Bull. Volcanol., 56,
207– 216.
Kazahaya, K., H. Shinohara, K. Uto, M. Odai, Y. Nakahori, H. Mori,
H. Iino, M. Miyashita, and J. Hirabayashi (2004), Gigantic SO2 emission
from Miyakejima volcano, Japan, caused by caldera collapse, Geology,
32, 425–428.
Me´trich, N., R. Clocchiatti, M. Mosbah, and M. Chaussidon (1993), The
1989– 1990 activity of Etna magma mingling and ascent of H2O-Cl-S-rich
basaltic magma. Evidence from melt inclusions, J. Volcanol. Geotherm.
Res., 59, 131– 144.
Me´trich, N., P. Allard, N. Spilliaert, D. Andronico, and M. Burton (2004),
2001 flank eruption of the alkali- and volatile-rich primitive basalt
responsible for Mount Etna’s evolution in the last three decades, Earth
Planet. Sci. Lett., 228, 1– 17.
Mizutani, Y., and T. Sugiura (1982), Variations in chemical and isotopic
compositions of fumarolic gases from Showashinzan volcano, Hokkaido,
Japan, Geochem. J., 16, 63–71.
Moretti, R., and P. Papale (2004), On the oxidation and volatile behavior in
multicomponent gas-melt equilibria, Chem. Geol., 213, 265–280.
Moretti, R., P. Papale, and G. Ottonello (2003), A model for the saturation
of C-O-H-S fluids in silicate melts, in Volcanic Degassing, edited by
C. Oppenheimer, D. Pyle, and J. Barclay, Geol. Soc. London Spec.
Pub., 213, 81–101.
Newman, S., and J. B. Lowenstern (2002), VOLATILECALC: A silicate
melt-H2O-CO2 solution model written in Visual Basic Excel, Comput.
Geosci., 2, 597– 604.
Ohba, T., J. Hirabayashi, and M. Yoshida (1994), Equilibrium temperature
and redox state of volcanic gas at Unzen volcano, Japan, J. Volcanol.
Geotherm. Res., 60, 263– 274.
Papale, P. (1999), Modeling of the solubility of a two-component H2O +
CO2 fluid in silicate liquids, Am. Mineral., 84, 477–492.
Scaillet, B., and M. Pichavant (2005), A model of sulphur solubility for
hydrous mafic melts: Application to the determination of magmatic fluid
compositions of Italian volcanoes, Ann. Geophys., 48, 671– 697.
Shinohara, H., K. Kazahaya, G. Saito, N. Matsushima, and Y. Kawanabe
(2002), Degassing activity from Iwodake rhyolitic cone, Satsuma-Iwojima
volcano, Japan: Formation of a new degassing vent, 1990 – 1999,
Earth Planets Space, 54, 175–185.
Shinohara, H., K. Kazahaya, G. Saito, K. Fukui, and M. Odai (2003a),
Variation of CO2/SO2 ratio in volcanic plumes of Miyakejima: Stable
degassing deduced from heliborne measurements, Geophys. Res. Lett.,
30(5), 1208, doi:10.1029/2002GL016105.
Shinohara, H., K. Fukui, K. Kazahaya, and G. Saito (2003b), Degassing
process of Miyakejima volcano: Implications of gas emission rate and
melt inclusion data, in Melt Inclusions in Volcanic Systems, edited by
B. De Vivo and B. Bodnar, Adv. Volcanol., 4, 147–161.
Shinohara, H. (2005), A new technique to estimate volcanic gas composition:
Plume measurements with a portable multi-sensor system, J. Volcanol.
Geotherm. Res., 143, 319– 333.
Shinohara, H., and J. Witter (2005), Volcanic gases emitted during mild
Strombolian activity of Villarrica volcano, Chile, Geophys. Res. Lett., 32,
L20308, doi:10.1029/2005GL024131.
Sparks, R. S., J. Barclay, C. Jaupart, H. M. Mader, and J. C. Phillips (1994),
Physical aspects of magma degassing I. Experimental and theoretical
constrains on vesiculation, in Volatiles in Magmas, edited by M. R. Carroll
and J. R. Holloway, Rev. Mineral., 30, 413– 445.
Spilliaert, N., P. Allard, N. Me´trich, and V. Sobolev (2006a), Melt inclusion
record of the conditions of ascent, degassing, and extrusion of volatilerich
alkali basalt during the powerful 2002 flank eruption of mount Etna
(Italy), J. Geophys. Res., 111, B04203, doi:10.1029/2005JB003934.
Spilliaert, N., N. Me´trich, and P. Allard (2006b), S-Cl-F degassing pattern
of water-rich alkali basalt: Modeling and relationship with eruption styles
on Mount Etna volcano, Earth Planet. Sci. Lett., 248, 772– 786.
Stevenson, D. S., and S. Blake (1998), Modeling the dynamics and thermodynamics
of volcanic degassing, Bull. Volcanol., 60, 307– 317.
Takeuchi, S., S. Nakashima, A. Tomiya, and H. Shinohara (2005), Experimental
constraints on the low gas permeability of vesicular magma during
decompression, Geophys. Res. Lett., 32, L10312, doi:10.1029/
2005GL022491.
Wallace, P. J. (2005), Volatiles in subduction zone magmas: Concentrations
and fluxes based on melt inclusion and volcanic gas data, J. Volcanol.
Geotherm. Res., 140, 217– 240.
S, Cl and F degassing as an indicator of volcanic dynamics: The 2001
eruption of Mount Etna, Geophys. Res. Lett., 29(11), 1556, doi:10.1029/
2002GL015032.
Aiuppa, A., C. Federico, G. Giudice, and S. Gurrieri (2005a), Chemical
mapping of a fumarolic field: La Fossa Crater, Vulcano Island (Aeolian
Islands, Italy), Geophys. Res. Lett., 13, L13309, doi:10.1029/
2005GL023207.
Aiuppa,A., S. Inguaggiato,A. J. S.McGonigle, M.O’Dwyer, C.Oppenheimer,
M. J. Padgett, D. Rouwet, and M. Valenza (2005b), H2S fluxes from
Mt. Etna, Stromboli, and Vulcano (Italy) and implications for the sulfur
budget at volcanoes, Geochim. Cosmochim. Acta, 69, 1861– 1871.
Aiuppa, A., C. Federico, G. Giudice, S. Gurrieri, M. Liuzzo, H. Shinohara,
R. Favara, and M. Valenza (2006), Rates of carbon dioxide plume degassing
from Mount Etna volcano, J. Geophys. Res., 111, B09207,
doi:10.1029/2006JB004307.
Aiuppa, A., R. Moretti, C. Federico, G. Giudice, S. Gurrieri, M. Liuzzo,
P. Papale, H. Shinohara, and M. Valenza (2007), Forecasting Etna
eruption by real-time observation of volcanic gas composition, Geology,
35, 1115– 1118.
Allard, P. (1997), Endogenous magma degassing and storage at Mount
Etna, Geophys. Res. Lett., 24, 2219– 2222.
Allard, P., B. Behncke, S. D’Amico, M. Neri, and S. Gambino (2006),
Mount Etna 1993– 2005: Anatomy of an evolving eruptive cycle, Earth
Sci. Rev., 78, 85– 114.
Allard, P., et al. (1991), Eruptive and diffuse emissions of CO2 from Mount
Etna, Nature, 351, 387– 391.
Allard, P., M. Burton, and F. Mure` (2005), Spectroscopic evidence for a
lava fountain driven by previously accumulated magmatic gases, Nature,
433, 407–410.
Andres, R. J., and A. D. Kasgnoc (1998), A time-averaged inventory of
subaerial volcanic sulfur emissions, J. Geophys. Res., 103, 25,251 –
25,261.
Burton, M. R., C. Oppenheimer, L. A. Horrocks, and P. W. Francis (2000),
Remote sensing of CO2 and H2O emission rates from Masaya volcano,
Nicaragua, Geology, 28, 915– 918.
Burton, M. R., P. Allard, F. Mure`, and C. Oppenheimer (2003), FTIR
remote sensing of fractional magma degassing at Mount Etna, Sicily, in
Volcanic Degassing, edited by C. Oppenheimer, D. Pyle, and J. Barclay,
Geol. Soc. London Spec. Pub., 213, 281–293.
Caltabiano, T., M. Burton, S. Giammanco, P. Allard, N. Bruno, F. Mure`,
and R. Romano (2004), Volcanic Gas Emissions from the Summit Craters
and Flanks of Mt. Etna, 1987–2000 in Mt. Etna: Volcano Laboratory,
Geophys. Monogr. Ser., vol. 143, edited by A. Bonaccorso et al., AGU,
Washington D. C.
Carroll, M. R., and J. D. Webster (1994), Solubilities of sulfur, noble gases,
nitrogen, chlorine and fluorine in magmas, in Volatiles in Magmas, edited
by M. R. Carroll and J. R. Holloway, Rev. Mineral., 30, 231– 279.
Chiodini, G., R. Cioni, L. Marini, and C. Panichi (1995), Origin of the
fumarolic fluids of Vulcano Island, Italy and implications for volcanic
surveillance, Bull. Volcanol., 57, 99– 110.
Eichelberger, J. C., C. R. Carrigan, H. R. Westrich, and J. R. Shannon
(1986), Non-explosive volcanism, Nature, 323, 598– 602.
Gerlach, T. M. (1991), Present-day CO2 emissions from volcanoes, Eos
Trans. AGU, 72, 240– 253.
Giggenbach, W. F. (1996), Chemical composition of volcanic gases, in
Monitoring and Mitigation of Volcanic Hazards, edited by R. Scarpa
and R. I. Tilling, Springer Verlag, Berlin-Heidelberg.
Giggenbach, W. F., and F. Le Guern (1976), The chemistry of magmatic
gases from Erta’Ale, Ethiopia, Geochim. Cosmochim. Acta, 40, 25– 30.
Giggenbach, W. F., and S. Matsuo (1991), Evaluation of results from second
and Third IAVCEI Field Workshop on Volcanic Gases, Mt. Usu,
Japan and White Island, N. Z. Appl. Geochem., 6, 125– 141.
Giggenbach, W. F., and D. S. Sheppard (1989), Variation in the temperature
and chemistry of White Island fumarole discharges 1972– 85, N. Z. Geol.
Surv. Bull., 103, 119–126.
Kazahaya, K., H. Shinohara, and G. Saito (1994), Excessive degassing of
Izu-Oshima volcano: Magma convection in a conduit, Bull. Volcanol., 56,
207– 216.
Kazahaya, K., H. Shinohara, K. Uto, M. Odai, Y. Nakahori, H. Mori,
H. Iino, M. Miyashita, and J. Hirabayashi (2004), Gigantic SO2 emission
from Miyakejima volcano, Japan, caused by caldera collapse, Geology,
32, 425–428.
Me´trich, N., R. Clocchiatti, M. Mosbah, and M. Chaussidon (1993), The
1989– 1990 activity of Etna magma mingling and ascent of H2O-Cl-S-rich
basaltic magma. Evidence from melt inclusions, J. Volcanol. Geotherm.
Res., 59, 131– 144.
Me´trich, N., P. Allard, N. Spilliaert, D. Andronico, and M. Burton (2004),
2001 flank eruption of the alkali- and volatile-rich primitive basalt
responsible for Mount Etna’s evolution in the last three decades, Earth
Planet. Sci. Lett., 228, 1– 17.
Mizutani, Y., and T. Sugiura (1982), Variations in chemical and isotopic
compositions of fumarolic gases from Showashinzan volcano, Hokkaido,
Japan, Geochem. J., 16, 63–71.
Moretti, R., and P. Papale (2004), On the oxidation and volatile behavior in
multicomponent gas-melt equilibria, Chem. Geol., 213, 265–280.
Moretti, R., P. Papale, and G. Ottonello (2003), A model for the saturation
of C-O-H-S fluids in silicate melts, in Volcanic Degassing, edited by
C. Oppenheimer, D. Pyle, and J. Barclay, Geol. Soc. London Spec.
Pub., 213, 81–101.
Newman, S., and J. B. Lowenstern (2002), VOLATILECALC: A silicate
melt-H2O-CO2 solution model written in Visual Basic Excel, Comput.
Geosci., 2, 597– 604.
Ohba, T., J. Hirabayashi, and M. Yoshida (1994), Equilibrium temperature
and redox state of volcanic gas at Unzen volcano, Japan, J. Volcanol.
Geotherm. Res., 60, 263– 274.
Papale, P. (1999), Modeling of the solubility of a two-component H2O +
CO2 fluid in silicate liquids, Am. Mineral., 84, 477–492.
Scaillet, B., and M. Pichavant (2005), A model of sulphur solubility for
hydrous mafic melts: Application to the determination of magmatic fluid
compositions of Italian volcanoes, Ann. Geophys., 48, 671– 697.
Shinohara, H., K. Kazahaya, G. Saito, N. Matsushima, and Y. Kawanabe
(2002), Degassing activity from Iwodake rhyolitic cone, Satsuma-Iwojima
volcano, Japan: Formation of a new degassing vent, 1990 – 1999,
Earth Planets Space, 54, 175–185.
Shinohara, H., K. Kazahaya, G. Saito, K. Fukui, and M. Odai (2003a),
Variation of CO2/SO2 ratio in volcanic plumes of Miyakejima: Stable
degassing deduced from heliborne measurements, Geophys. Res. Lett.,
30(5), 1208, doi:10.1029/2002GL016105.
Shinohara, H., K. Fukui, K. Kazahaya, and G. Saito (2003b), Degassing
process of Miyakejima volcano: Implications of gas emission rate and
melt inclusion data, in Melt Inclusions in Volcanic Systems, edited by
B. De Vivo and B. Bodnar, Adv. Volcanol., 4, 147–161.
Shinohara, H. (2005), A new technique to estimate volcanic gas composition:
Plume measurements with a portable multi-sensor system, J. Volcanol.
Geotherm. Res., 143, 319– 333.
Shinohara, H., and J. Witter (2005), Volcanic gases emitted during mild
Strombolian activity of Villarrica volcano, Chile, Geophys. Res. Lett., 32,
L20308, doi:10.1029/2005GL024131.
Sparks, R. S., J. Barclay, C. Jaupart, H. M. Mader, and J. C. Phillips (1994),
Physical aspects of magma degassing I. Experimental and theoretical
constrains on vesiculation, in Volatiles in Magmas, edited by M. R. Carroll
and J. R. Holloway, Rev. Mineral., 30, 413– 445.
Spilliaert, N., P. Allard, N. Me´trich, and V. Sobolev (2006a), Melt inclusion
record of the conditions of ascent, degassing, and extrusion of volatilerich
alkali basalt during the powerful 2002 flank eruption of mount Etna
(Italy), J. Geophys. Res., 111, B04203, doi:10.1029/2005JB003934.
Spilliaert, N., N. Me´trich, and P. Allard (2006b), S-Cl-F degassing pattern
of water-rich alkali basalt: Modeling and relationship with eruption styles
on Mount Etna volcano, Earth Planet. Sci. Lett., 248, 772– 786.
Stevenson, D. S., and S. Blake (1998), Modeling the dynamics and thermodynamics
of volcanic degassing, Bull. Volcanol., 60, 307– 317.
Takeuchi, S., S. Nakashima, A. Tomiya, and H. Shinohara (2005), Experimental
constraints on the low gas permeability of vesicular magma during
decompression, Geophys. Res. Lett., 32, L10312, doi:10.1029/
2005GL022491.
Wallace, P. J. (2005), Volatiles in subduction zone magmas: Concentrations
and fluxes based on melt inclusion and volcanic gas data, J. Volcanol.
Geotherm. Res., 140, 217– 240.
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