Secular variations of helium and carbon isotopes at Galeras volcano, Colombia

Yuji Sano; Toshitaka Gamo

doi:10.1016/S0377-0273(96)00098-4

Secular variations of helium and carbon isotopes at Galeras volcano, Colombia

Yuji Sano
, Toshitaka Gamo

Earth and Space Exploration, School of (SESE)

Research output: Contribution to journal › Article › peer-review

56 Scopus citations

Abstract

We have measured ³He/⁴He, ⁴He/²⁰Ne and CO₂/⁴He ratios, and δ¹³C values of CO₂ in eighteen samples from crater fumaroles of Galeras volcano, Colombia, and seven samples of bubbling gases of the Pandiaco mineral spring located about 8 km east of the volcano from April 1988 to July 1995. The ³He/⁴He ratios of crater fumaroles, corrected for atmospheric contamination, increased significantly from 5.47 R_atm in December 1989 to 7.93 R_atm in August 1990 and reached a maximum of 8.84 R_atm in May 1992. The ratio then decreased gradually until July 1995. Overall variation of helium isotopes appears to be related to the current activity of the volcano. The ³He/⁴He ratios of Pandiaco mineral spring were constant between April 1988 and November 1991 and increased in April 1993, although experimental error is large. The δ¹³C values of CO₂ of crater fumaroles show negative correlation to the helium isotopes, while those of Pandiaco are relatively constant. Based on the δ¹³C values and CO₂/³He ratios, it is possible to estimate fractions of upper mantle carbon in these samples. Calculated mantle fractions are 3-10% in crater fumaroles, while those in Pandiaco spring are negligibly small.

Original language	English (US)
Pages (from-to)	255-265
Number of pages	11
Journal	Journal of Volcanology and Geothermal Research
Volume	77
Issue number	1-4
DOIs	https://doi.org/10.1016/S0377-0273(96)00098-4
State	Published - May 1997

Keywords

Carbon isotopes
Galeras volcano
Helium isotopes
Volcanic gas

ASJC Scopus subject areas

Geophysics
Geochemistry and Petrology

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10.1016/S0377-0273(96)00098-4

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title = "Secular variations of helium and carbon isotopes at Galeras volcano, Colombia",

abstract = "We have measured 3He/4He, 4He/20Ne and CO2/4He ratios, and δ13C values of CO2 in eighteen samples from crater fumaroles of Galeras volcano, Colombia, and seven samples of bubbling gases of the Pandiaco mineral spring located about 8 km east of the volcano from April 1988 to July 1995. The 3He/4He ratios of crater fumaroles, corrected for atmospheric contamination, increased significantly from 5.47 Ratm in December 1989 to 7.93 Ratm in August 1990 and reached a maximum of 8.84 Ratm in May 1992. The ratio then decreased gradually until July 1995. Overall variation of helium isotopes appears to be related to the current activity of the volcano. The 3He/4He ratios of Pandiaco mineral spring were constant between April 1988 and November 1991 and increased in April 1993, although experimental error is large. The δ13C values of CO2 of crater fumaroles show negative correlation to the helium isotopes, while those of Pandiaco are relatively constant. Based on the δ13C values and CO2/3He ratios, it is possible to estimate fractions of upper mantle carbon in these samples. Calculated mantle fractions are 3-10\% in crater fumaroles, while those in Pandiaco spring are negligibly small.",

keywords = "Carbon isotopes, Galeras volcano, Helium isotopes, Volcanic gas",

author = "Yuji Sano and Toshitaka Gamo",

note = "Funding Information: We thank T.P. Fischer and M.L. Calvache V. t{\textquoteright}o\textasciitilde{} collecting some samples.W e are grateful to N. Taka-hata, H. Hiyagon and M. Tsutsumi for help in helium and carbon isotope measurementsT. his work is dedicatedt o the memory of Jose A. Zapata G.. who lost his life in the 14 January 1993 eruption of Galeras. Jose collected important samples for this study and made major contributions of our understanding of gas geochemistrya t Galeras through his efforts in the field and laboratory. SNW also ac- knowledges the US NSF for support of the research and Galeras Workshop. Comments and suggestions by editor, John Stix, and two anonymous reviewers were useful to revision of the original manuscript. Copyright: Copyright 2018 Elsevier B.V., All rights reserved.",

year = "1997",

month = may,

doi = "10.1016/S0377-0273(96)00098-4",

language = "English (US)",

volume = "77",

pages = "255--265",

journal = "Journal of Volcanology and Geothermal Research",

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TY - JOUR

T1 - Secular variations of helium and carbon isotopes at Galeras volcano, Colombia

AU - Sano, Yuji

AU - Gamo, Toshitaka

N1 - Funding Information: We thank T.P. Fischer and M.L. Calvache V. t’o~ collecting some samples.W e are grateful to N. Taka-hata, H. Hiyagon and M. Tsutsumi for help in helium and carbon isotope measurementsT. his work is dedicatedt o the memory of Jose A. Zapata G.. who lost his life in the 14 January 1993 eruption of Galeras. Jose collected important samples for this study and made major contributions of our understanding of gas geochemistrya t Galeras through his efforts in the field and laboratory. SNW also ac- knowledges the US NSF for support of the research and Galeras Workshop. Comments and suggestions by editor, John Stix, and two anonymous reviewers were useful to revision of the original manuscript. Copyright: Copyright 2018 Elsevier B.V., All rights reserved.

PY - 1997/5

Y1 - 1997/5

N2 - We have measured 3He/4He, 4He/20Ne and CO2/4He ratios, and δ13C values of CO2 in eighteen samples from crater fumaroles of Galeras volcano, Colombia, and seven samples of bubbling gases of the Pandiaco mineral spring located about 8 km east of the volcano from April 1988 to July 1995. The 3He/4He ratios of crater fumaroles, corrected for atmospheric contamination, increased significantly from 5.47 Ratm in December 1989 to 7.93 Ratm in August 1990 and reached a maximum of 8.84 Ratm in May 1992. The ratio then decreased gradually until July 1995. Overall variation of helium isotopes appears to be related to the current activity of the volcano. The 3He/4He ratios of Pandiaco mineral spring were constant between April 1988 and November 1991 and increased in April 1993, although experimental error is large. The δ13C values of CO2 of crater fumaroles show negative correlation to the helium isotopes, while those of Pandiaco are relatively constant. Based on the δ13C values and CO2/3He ratios, it is possible to estimate fractions of upper mantle carbon in these samples. Calculated mantle fractions are 3-10% in crater fumaroles, while those in Pandiaco spring are negligibly small.

AB - We have measured 3He/4He, 4He/20Ne and CO2/4He ratios, and δ13C values of CO2 in eighteen samples from crater fumaroles of Galeras volcano, Colombia, and seven samples of bubbling gases of the Pandiaco mineral spring located about 8 km east of the volcano from April 1988 to July 1995. The 3He/4He ratios of crater fumaroles, corrected for atmospheric contamination, increased significantly from 5.47 Ratm in December 1989 to 7.93 Ratm in August 1990 and reached a maximum of 8.84 Ratm in May 1992. The ratio then decreased gradually until July 1995. Overall variation of helium isotopes appears to be related to the current activity of the volcano. The 3He/4He ratios of Pandiaco mineral spring were constant between April 1988 and November 1991 and increased in April 1993, although experimental error is large. The δ13C values of CO2 of crater fumaroles show negative correlation to the helium isotopes, while those of Pandiaco are relatively constant. Based on the δ13C values and CO2/3He ratios, it is possible to estimate fractions of upper mantle carbon in these samples. Calculated mantle fractions are 3-10% in crater fumaroles, while those in Pandiaco spring are negligibly small.

KW - Carbon isotopes

KW - Galeras volcano

KW - Helium isotopes

KW - Volcanic gas

UR - https://www.scopus.com/pages/publications/0030807333

UR - https://www.scopus.com/pages/publications/0030807333#tab=citedBy

U2 - 10.1016/S0377-0273(96)00098-4

DO - 10.1016/S0377-0273(96)00098-4

M3 - Article

SN - 0377-0273

VL - 77

SP - 255

EP - 265

JO - Journal of Volcanology and Geothermal Research

JF - Journal of Volcanology and Geothermal Research

IS - 1-4

ER -

Secular variations of helium and carbon isotopes at Galeras volcano, Colombia

Abstract

Keywords

ASJC Scopus subject areas

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