Skip to main content

Volume 54 Supplement 3

Special Issue: Satsuma-Iwojima: Continuous degassing of a rhyolitic volcano

Carbon isotope systematics of CO2, CO and CH4 in fumarolic gases from Satsuma-Iwojima volcanic island, Japan


Carbon isotopic composition (δ13C) of CO2, CO and CH4 were determined for fumarolic gases from Satsuma-Iwojima, to range from −3.1 to −2.6‰, from −11.6 to −2.8‰ and from −56 to −37‰, respectively. Carbon isotope exchange equilibrium temperature between CO2 and CO was calculated to be ranging from 896° to 950°C for high temperature (691° to 882°C) fumarolic gases, suggesting that CO2 and CO were in isotopic equilibrium near the vent temperature. However, low temperature (<650°C) gases were not in isotopic equilibrium between CO2 and CO under any realistic conditions. The correlations of δ13C(CO), CO/CO2 ratio and temperature can be explained in terms of kinetic conversion of CO to CO2 with decreasing temperature. The δ13C values of CH4 and CO2 revealed that the CH4 was not equilibrated in carbon isotope exchange reaction with CO2 even at fumarolic gas temperature near 900°C. Correlation of δ13C(CH4) and CH4/C2H6 ratio indicate that CH4 of the low CH4/CO2 ratio group (<10−5) is mainly originated from thermogenic decomposition of organic matter, while the high CH4/CO2 ratio group gas (7.7 × 10−4 to 7.4 × 10−3) is contaminated by the CH4-rich gas with δ13C value of about −40‰.


  • Giggenbach, W. F., Redox processes governing the chemistry of fumarolic gas discharges from White Island, New Zealand, Appl. Geochem., 2, 143–161, 1987.

    Article  Google Scholar 

  • Giggenbach, W. F., Relative importance of thermodynamic and kinetic process in governing the chemical and isotopic composition of carbon gases in high-heatflow sedimentary basins, Geochim. Cosmochim. Acta, 61, 3763–3785, 1997.

    Article  Google Scholar 

  • Kamada, M., Volcanoes and geothermy of Satsuma-Iwojima, Kagoshima prefecture, J. Japan Geothermal Energy Assoc., 3, 1–23, 1964 (in Japanese).

    Google Scholar 

  • Kiyosu, Y. and N. Asada, Light hydrocarbons in volcanic gases from the Japanese island arc, Geochem. J., 29, 231–242, 1995.

    Article  Google Scholar 

  • Kiyosu, Y., N. Asada, and Y. Yoshida, Origin of light hydrocarbon gases from the Matsukawa geothermal area in Japan, Chem. Geol. (Isotope Geoscience Section), 94, 321–329, 1992.

    Article  Google Scholar 

  • Lupton, J. E., Terrestrial inert gases: Isotope tracer studies and clues to primordial components in the mantle, Annu. Rev. Earth and Planet. Sci., 11, 37–414, 1983.

    Article  Google Scholar 

  • Marty, B., A. Jambon, and Y. Sano, Helium isotopes and CO2 in volcanic gases of Japan, Chem. Geol., 76, 25–40, 1989.

    Article  Google Scholar 

  • Matsubaya, O., A. Ueda, M. Kusakabe, Y. Matsuhisa, H. Sakai, and A. Sasaki, An isotopic study of the volcanoes and hot springs in Satsuma-Iwojima and some areas in Kyushu, Bull. Geol. Surv. Japan, 26, 375–392, 1975 (in Japanese with English abstract).

    Google Scholar 

  • Matsuo, S., T. Suzuoki, M. Kusakabe, H. Wada, and M. Suzuki, Isotopic and chemical compositions of volcanic gases from Satsuma-Iwojima, Japan, Geochem. J., 8, 165–173, 1974.

    Article  Google Scholar 

  • Miyashiro, A. and I. Kushiro, Petrology III (Petrogenesis), pp. 245, Kyoritsu Shuppan, Japan, 1977 (in Japanese).

    Google Scholar 

  • Ohba, T., Chemical equilibrium in high temperature volcanic gas, Chikyukagaku, 31, 99–110, 1997 (in Japanese with English abstract).

    Google Scholar 

  • Ono, K., T. Soya, and T. Hosono, Geology of Satsuma-Io-jima district, Quadrangle Series, Scale 1:50,000, Tanegashima (16) No. 2, Geol. Surv. Japan, 1982 (in Japanese with English summary).

  • Ozawa, T., Chemical analysis of volcanic gases: I. Chemical analysis of volcanic gases containing water vapor, hydrogen chloride, sulfur dioxide, hydrogen sulfide, carbon dioxide, etc, Geochemistry International, 5, 939–947, 1968.

    Google Scholar 

  • Richet, P., Y. Bottinga, and M. Javoy, A review of hydrogen, carbon, nitrogen, oxygen, sulphur, and chlorine stable isotope fractionation among gaseous molecules, Annu. Rev. Earth and Planet. Sci., 5, 65–110, 1977.

    Article  Google Scholar 

  • Sano, Y. and B. Marty, Origin of carbon in fumarolic gas from island arcs, Chem. Geol. (Isotope Geoscience Section), 119, 265–274, 1995.

    Google Scholar 

  • Sano, Y. and H. Wakita, Geographical distribution of 3He/4He ratios in Japan: Implications for arc tectonics and incipient magmatism, J. Geophys. Res., 90, 8729–8741, 1985.

    Article  Google Scholar 

  • Sano, Y., T. Tominaga, Y. Nakamura, and H. Wakita, 3He/4He ratios of methane-rich natural gases in Japan, Geochem. J., 16, 237–245, 1982.

    Article  Google Scholar 

  • Sato, M., U. Tsunogai, J. Ishibashi, K. Notsu, and H. Wakita, Carbon isotopic measurement of extremely low amounts of CH4: Application to volcanic gases from Satsuma-Iwojima, Japan, Anal. Sci., 15, 513–516, 1999.

    Article  Google Scholar 

  • Schoell, M., The hydrogen and carbon isotopic composition of methane from natural gases of various origins, Geochim. Cosmochim. Acta, 44, 649–661, 1980.

    Article  Google Scholar 

  • Shinohara, H., W. F. Giggenbach, K. Kazahaya, and J. W. Hedenquist, Geochemistry of volcanic gases and hot springs of Satsuma-Iwojima, Japan: Following Matsuo, Geochem. J., 27, 271–285, 1993.

    Article  Google Scholar 

  • Symonds, R. B., W. I. Rose, G. J. S. Bluth, and T. M. Gerlach, Volcanic-gas studies: Methods, results, and applications, Reviews in Mineralogy, 30, 1–66, 1994.

    Google Scholar 

  • Welhan, J. A. and H. Craig, Methane, hydrogen and helium in hydrothermal fluids at 21°N on the EAST PACIFIC RISE, in Hydrothermal Process at Seafloor Spreading Centers, edited by P. A. Rona et al., pp. 391–408, Plenum, New York, 1983.

    Chapter  Google Scholar 

Download references

Author information

Authors and Affiliations


Corresponding author

Correspondence to Masanori Sato.

Rights and permissions

Reprints and Permissions

About this article

Verify currency and authenticity via CrossMark

Cite this article

Sato, M., Mori, T., Shimoike, Y. et al. Carbon isotope systematics of CO2, CO and CH4 in fumarolic gases from Satsuma-Iwojima volcanic island, Japan. Earth Planet Sp 54, 257–263 (2002).

Download citation

  • Received:

  • Revised:

  • Accepted:

  • Published:

  • Issue Date:

  • DOI:


  • Carbon Isotopic Composition
  • Fumarolic Temperature
  • Kinetic Conversion
  • Isotopic Exchange Equilibrium
  • Kikai Caldera