The 2012-2016 eruptive cycle at Copahue volcano (Argentina) versus the peripheral gas manifestations: hints from the chemical and isotopic features of fumarolic fluids.
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| Title: | The 2012-2016 eruptive cycle at Copahue volcano (Argentina) versus the peripheral gas manifestations: hints from the chemical and isotopic features of fumarolic fluids. |
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| Authors: | Tassi, F. franco.tassi@unifi.it, Agusto, M.1, Lamberti, C.1, Caselli, A.2, Pecoraino, G.3, Caponi, C.4, Szentiványi, J.1, Venturi, S., Vaselli, O. |
| Source: | Bulletin of Volcanology. Oct2017, Vol. 79 Issue 10, p1-14. 14p. |
| Subject Terms: | *Volcanism, *Volcanic eruptions, *Volcanic gases, *Magmas, *Volcanic ash, tuff, etc. |
| Abstract: | This study presents the chemical and isotopic compositions of hydrothermal gases from fumaroles discharging around Copahue volcano (Argentina). Gas samples, including those from two fumaroles at the active summit crater, were collected during 13 surveys carried out by different research teams from 1976 to February 2016. The time-series of H, CO and light hydrocarbons showed episodic increases related to the main events of the last eruptive cycle that started on 19 July 2012. Concentration peaks were likely caused by enhanced input of hot magmatic fluids affecting the hydrothermal reservoir. These data contrast with the temporal variations shown by Rc/ Ra and δC-CO values in 2012-2014, which indicated an increasing input from a crustal fluid source. In 2015-2016, however, these isotopic parameters showed opposite trends; their composition became closer to that of the two summit fumaroles, which possibly corresponds to that of the deep magmatic-related end-member. The delayed and reduced compositional changes in the peripheral hydrothermal fluid discharge in response to the 2012-2016 eruptive events suggest that geochemical surveys of these emissions are unlikely to provide premonitory signals of volcanic unrest if the volcanic activity remains centered in the main crater. Instead, an instrument which is able to provide measurements of volcanic gases in the air (e.g. MultiGAS) may be used to detect changes at the summit crater. Otherwise, monitoring of seismic activity and ground deformation, as well as the periodic measurement of the chemistry of the water in the Rio Agrio, which is fed by thermal discharge from the summit crater, seem to represent the most reliable means of monitoring at Copahue. However, the relative compositional stability of the hydrothermal reservoir is a great advantage in terms of geothermal resource exploitation and could encourage new investments in the Copahue geothermal project which was abandoned in the 1990s. [ABSTRACT FROM AUTHOR] |
| Database: | Energy & Power Source |
| FullText | Links: – Type: pdflink Text: Availability: 0 |
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| Header | DbId: enr DbLabel: Energy & Power Source An: 125825650 AccessLevel: 6 PubType: Academic Journal PubTypeId: academicJournal PreciseRelevancyScore: 0 |
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| Items | – Name: Title Label: Title Group: Ti Data: The 2012-2016 eruptive cycle at Copahue volcano (Argentina) versus the peripheral gas manifestations: hints from the chemical and isotopic features of fumarolic fluids. – Name: Author Label: Authors Group: Au Data: <searchLink fieldCode="AR" term="%22Tassi%2C+F%2E%22">Tassi, F.</searchLink><i> franco.tassi@unifi.it</i><br /><searchLink fieldCode="AR" term="%22Agusto%2C+M%2E%22">Agusto, M.</searchLink><relatesTo>1</relatesTo><br /><searchLink fieldCode="AR" term="%22Lamberti%2C+C%2E%22">Lamberti, C.</searchLink><relatesTo>1</relatesTo><br /><searchLink fieldCode="AR" term="%22Caselli%2C+A%2E%22">Caselli, A.</searchLink><relatesTo>2</relatesTo><br /><searchLink fieldCode="AR" term="%22Pecoraino%2C+G%2E%22">Pecoraino, G.</searchLink><relatesTo>3</relatesTo><br /><searchLink fieldCode="AR" term="%22Caponi%2C+C%2E%22">Caponi, C.</searchLink><relatesTo>4</relatesTo><br /><searchLink fieldCode="AR" term="%22Szentiványi%2C+J%2E%22">Szentiványi, J.</searchLink><relatesTo>1</relatesTo><br /><searchLink fieldCode="AR" term="%22Venturi%2C+S%2E%22">Venturi, S.</searchLink><br /><searchLink fieldCode="AR" term="%22Vaselli%2C+O%2E%22">Vaselli, O.</searchLink> – Name: TitleSource Label: Source Group: Src Data: <searchLink fieldCode="JN" term="%22Bulletin+of+Volcanology%22">Bulletin of Volcanology</searchLink>. Oct2017, Vol. 79 Issue 10, p1-14. 14p. – Name: Subject Label: Subject Terms Group: Su Data: *<searchLink fieldCode="DE" term="%22Volcanism%22">Volcanism</searchLink><br />*<searchLink fieldCode="DE" term="%22Volcanic+eruptions%22">Volcanic eruptions</searchLink><br />*<searchLink fieldCode="DE" term="%22Volcanic+gases%22">Volcanic gases</searchLink><br />*<searchLink fieldCode="DE" term="%22Magmas%22">Magmas</searchLink><br />*<searchLink fieldCode="DE" term="%22Volcanic+ash%2C+tuff%2C+etc%2E%22">Volcanic ash, tuff, etc.</searchLink> – Name: Abstract Label: Abstract Group: Ab Data: This study presents the chemical and isotopic compositions of hydrothermal gases from fumaroles discharging around Copahue volcano (Argentina). Gas samples, including those from two fumaroles at the active summit crater, were collected during 13 surveys carried out by different research teams from 1976 to February 2016. The time-series of H, CO and light hydrocarbons showed episodic increases related to the main events of the last eruptive cycle that started on 19 July 2012. Concentration peaks were likely caused by enhanced input of hot magmatic fluids affecting the hydrothermal reservoir. These data contrast with the temporal variations shown by Rc/ Ra and δC-CO values in 2012-2014, which indicated an increasing input from a crustal fluid source. In 2015-2016, however, these isotopic parameters showed opposite trends; their composition became closer to that of the two summit fumaroles, which possibly corresponds to that of the deep magmatic-related end-member. The delayed and reduced compositional changes in the peripheral hydrothermal fluid discharge in response to the 2012-2016 eruptive events suggest that geochemical surveys of these emissions are unlikely to provide premonitory signals of volcanic unrest if the volcanic activity remains centered in the main crater. Instead, an instrument which is able to provide measurements of volcanic gases in the air (e.g. MultiGAS) may be used to detect changes at the summit crater. Otherwise, monitoring of seismic activity and ground deformation, as well as the periodic measurement of the chemistry of the water in the Rio Agrio, which is fed by thermal discharge from the summit crater, seem to represent the most reliable means of monitoring at Copahue. However, the relative compositional stability of the hydrothermal reservoir is a great advantage in terms of geothermal resource exploitation and could encourage new investments in the Copahue geothermal project which was abandoned in the 1990s. [ABSTRACT FROM AUTHOR] |
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| RecordInfo | BibRecord: BibEntity: Identifiers: – Type: doi Value: 10.1007/s00445-017-1151-7 Languages: – Code: eng Text: English PhysicalDescription: Pagination: PageCount: 14 StartPage: 1 Subjects: – SubjectFull: Volcanism Type: general – SubjectFull: Volcanic eruptions Type: general – SubjectFull: Volcanic gases Type: general – SubjectFull: Magmas Type: general – SubjectFull: Volcanic ash, tuff, etc. Type: general Titles: – TitleFull: The 2012-2016 eruptive cycle at Copahue volcano (Argentina) versus the peripheral gas manifestations: hints from the chemical and isotopic features of fumarolic fluids. Type: main BibRelationships: HasContributorRelationships: – PersonEntity: Name: NameFull: Tassi, F. – PersonEntity: Name: NameFull: Agusto, M. – PersonEntity: Name: NameFull: Lamberti, C. – PersonEntity: Name: NameFull: Caselli, A. – PersonEntity: Name: NameFull: Pecoraino, G. – PersonEntity: Name: NameFull: Caponi, C. – PersonEntity: Name: NameFull: Szentiványi, J. – PersonEntity: Name: NameFull: Venturi, S. – PersonEntity: Name: NameFull: Vaselli, O. IsPartOfRelationships: – BibEntity: Dates: – D: 01 M: 10 Text: Oct2017 Type: published Y: 2017 Identifiers: – Type: issn-print Value: 02588900 Numbering: – Type: volume Value: 79 – Type: issue Value: 10 Titles: – TitleFull: Bulletin of Volcanology Type: main |
| ResultId | 1 |
