Sources and transport of fluid and heat at the newly-developed Theistareykir Geothermal Field, Iceland
International audience Successful management of geothermal energy requires detailed understanding of physical and chemical conditions within the field prior to exploitation. It is thus crucial to identify fluids involved and their residence times, as well as the heat source, so as to assess the pote...
Published in: | Journal of Volcanology and Geothermal Research |
---|---|
Main Authors: | , , , , , , , , , , |
Other Authors: | , , , |
Format: | Article in Journal/Newspaper |
Language: | English |
Published: |
HAL CCSD
2020
|
Subjects: | |
Online Access: | https://hal-insu.archives-ouvertes.fr/insu-03661433 https://doi.org/10.1016/j.jvolgeores.2020.107062 |
id |
ftunivnantes:oai:HAL:insu-03661433v1 |
---|---|
record_format |
openpolar |
institution |
Open Polar |
collection |
Université de Nantes: HAL-UNIV-NANTES |
op_collection_id |
ftunivnantes |
language |
English |
topic |
Noble gases Stable isotopes Geothermal resources Northern Volcanic Zone Theistareykir Iceland [SDU]Sciences of the Universe [physics] |
spellingShingle |
Noble gases Stable isotopes Geothermal resources Northern Volcanic Zone Theistareykir Iceland [SDU]Sciences of the Universe [physics] Saby, Marion Pinti, Daniele L. van Hinsberg, Vincent Gautason, Bjarni Sigurðardóttir, Ásgerður Castro, Clara Hall, Chris Óskarsson, Finnbogi Rocher, Océane Hélie, Jean-François Méjean, Pauline Sources and transport of fluid and heat at the newly-developed Theistareykir Geothermal Field, Iceland |
topic_facet |
Noble gases Stable isotopes Geothermal resources Northern Volcanic Zone Theistareykir Iceland [SDU]Sciences of the Universe [physics] |
description |
International audience Successful management of geothermal energy requires detailed understanding of physical and chemical conditions within the field prior to exploitation. It is thus crucial to identify fluids involved and their residence times, as well as the heat source, so as to assess the potential of the resource in terms of energy production. To this end, a geochemical study of relatively undisturbed fluids from the newly-developed Theistareykir geothermal field, Northern Volcanic Zone, Iceland was carried out on production wells, fumaroles, and mud pots. Noble gas (He, Ne, Ar, Kr, and Xe) elemental and isotopic abundances and stable isotopes (δ 18 O and δ 2 H) were measured to determine the system fluid sources and dynamics as exploitation proceeds. Results of this study, together with previously published data, show that four fluid sources are present: modern and local meteoric water (48.9%); sub-modern meteoric water from regional highlands precipitation (10.6%); pre-Holocene glaciated meteoric water (40.4%) with strongly depleted δ 2 H values of -127‰, calculated 40 K- 40 Ar* fluid residence times from 57 ± 20 ka to 92 ± 30 ka and a (U/Th)- 4 He fluid residence times from 96 ± 50 ka to 160 ± 80 ka; and, finally, 3 He-rich magmatic fluids. Concomitant enrichment in 18 O and radiogenic 4 He suggests that some fluids reside a long time in the reservoir, exchanging O and He with reservoir rocks. Maximum estimated helium isotopic ratios, 3 He/ 4 He (R), of 11.45 Ra (Ra = atmospheric ratio) show that the magma beneath Theistareykir is a depleted mid-ocean ridge basalt (MORB) mantle (DMM), with less influence (8.7 to 12.7%) of the Icelandic mantle plume source. Calculated heat (Q)/ 3 He ratios plotted vs. R/Ra and 4 He/ 36 Ar ratios suggest that convective heat transport dominates the eastern part of the field where the magmatic heat source is located, while in other parts of the field, heat conduction seems to be dominant. Boiling and phase separation exists in the field, as indicated by δ 18 O values ... |
author2 |
Géosciences Environnement Toulouse (GET) Institut de Recherche pour le Développement (IRD)-Université Toulouse III - Paul Sabatier (UT3) Université Fédérale Toulouse Midi-Pyrénées-Université Fédérale Toulouse Midi-Pyrénées-Institut national des sciences de l'Univers (INSU - CNRS)-Observatoire Midi-Pyrénées (OMP) Université Fédérale Toulouse Midi-Pyrénées-Université Fédérale Toulouse Midi-Pyrénées-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National d'Études Spatiales Toulouse (CNES)-Centre National de la Recherche Scientifique (CNRS)-Météo-France -Institut de Recherche pour le Développement (IRD)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National d'Études Spatiales Toulouse (CNES)-Centre National de la Recherche Scientifique (CNRS)-Météo-France -Centre National de la Recherche Scientifique (CNRS) |
format |
Article in Journal/Newspaper |
author |
Saby, Marion Pinti, Daniele L. van Hinsberg, Vincent Gautason, Bjarni Sigurðardóttir, Ásgerður Castro, Clara Hall, Chris Óskarsson, Finnbogi Rocher, Océane Hélie, Jean-François Méjean, Pauline |
author_facet |
Saby, Marion Pinti, Daniele L. van Hinsberg, Vincent Gautason, Bjarni Sigurðardóttir, Ásgerður Castro, Clara Hall, Chris Óskarsson, Finnbogi Rocher, Océane Hélie, Jean-François Méjean, Pauline |
author_sort |
Saby, Marion |
title |
Sources and transport of fluid and heat at the newly-developed Theistareykir Geothermal Field, Iceland |
title_short |
Sources and transport of fluid and heat at the newly-developed Theistareykir Geothermal Field, Iceland |
title_full |
Sources and transport of fluid and heat at the newly-developed Theistareykir Geothermal Field, Iceland |
title_fullStr |
Sources and transport of fluid and heat at the newly-developed Theistareykir Geothermal Field, Iceland |
title_full_unstemmed |
Sources and transport of fluid and heat at the newly-developed Theistareykir Geothermal Field, Iceland |
title_sort |
sources and transport of fluid and heat at the newly-developed theistareykir geothermal field, iceland |
publisher |
HAL CCSD |
publishDate |
2020 |
url |
https://hal-insu.archives-ouvertes.fr/insu-03661433 https://doi.org/10.1016/j.jvolgeores.2020.107062 |
genre |
Iceland |
genre_facet |
Iceland |
op_source |
Journal of Volcanology and Geothermal Research https://hal-insu.archives-ouvertes.fr/insu-03661433 Journal of Volcanology and Geothermal Research, 2020, 405, ⟨10.1016/j.jvolgeores.2020.107062⟩ |
op_relation |
info:eu-repo/semantics/altIdentifier/doi/10.1016/j.jvolgeores.2020.107062 insu-03661433 https://hal-insu.archives-ouvertes.fr/insu-03661433 BIBCODE: 2020JVGR.40507062S doi:10.1016/j.jvolgeores.2020.107062 |
op_doi |
https://doi.org/10.1016/j.jvolgeores.2020.107062 |
container_title |
Journal of Volcanology and Geothermal Research |
container_volume |
405 |
container_start_page |
107062 |
_version_ |
1766038166740926464 |
spelling |
ftunivnantes:oai:HAL:insu-03661433v1 2023-05-15T16:48:03+02:00 Sources and transport of fluid and heat at the newly-developed Theistareykir Geothermal Field, Iceland Saby, Marion Pinti, Daniele L. van Hinsberg, Vincent Gautason, Bjarni Sigurðardóttir, Ásgerður Castro, Clara Hall, Chris Óskarsson, Finnbogi Rocher, Océane Hélie, Jean-François Méjean, Pauline Géosciences Environnement Toulouse (GET) Institut de Recherche pour le Développement (IRD)-Université Toulouse III - Paul Sabatier (UT3) Université Fédérale Toulouse Midi-Pyrénées-Université Fédérale Toulouse Midi-Pyrénées-Institut national des sciences de l'Univers (INSU - CNRS)-Observatoire Midi-Pyrénées (OMP) Université Fédérale Toulouse Midi-Pyrénées-Université Fédérale Toulouse Midi-Pyrénées-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National d'Études Spatiales Toulouse (CNES)-Centre National de la Recherche Scientifique (CNRS)-Météo-France -Institut de Recherche pour le Développement (IRD)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National d'Études Spatiales Toulouse (CNES)-Centre National de la Recherche Scientifique (CNRS)-Météo-France -Centre National de la Recherche Scientifique (CNRS) 2020 https://hal-insu.archives-ouvertes.fr/insu-03661433 https://doi.org/10.1016/j.jvolgeores.2020.107062 en eng HAL CCSD info:eu-repo/semantics/altIdentifier/doi/10.1016/j.jvolgeores.2020.107062 insu-03661433 https://hal-insu.archives-ouvertes.fr/insu-03661433 BIBCODE: 2020JVGR.40507062S doi:10.1016/j.jvolgeores.2020.107062 Journal of Volcanology and Geothermal Research https://hal-insu.archives-ouvertes.fr/insu-03661433 Journal of Volcanology and Geothermal Research, 2020, 405, ⟨10.1016/j.jvolgeores.2020.107062⟩ Noble gases Stable isotopes Geothermal resources Northern Volcanic Zone Theistareykir Iceland [SDU]Sciences of the Universe [physics] info:eu-repo/semantics/article Journal articles 2020 ftunivnantes https://doi.org/10.1016/j.jvolgeores.2020.107062 2023-02-22T02:00:17Z International audience Successful management of geothermal energy requires detailed understanding of physical and chemical conditions within the field prior to exploitation. It is thus crucial to identify fluids involved and their residence times, as well as the heat source, so as to assess the potential of the resource in terms of energy production. To this end, a geochemical study of relatively undisturbed fluids from the newly-developed Theistareykir geothermal field, Northern Volcanic Zone, Iceland was carried out on production wells, fumaroles, and mud pots. Noble gas (He, Ne, Ar, Kr, and Xe) elemental and isotopic abundances and stable isotopes (δ 18 O and δ 2 H) were measured to determine the system fluid sources and dynamics as exploitation proceeds. Results of this study, together with previously published data, show that four fluid sources are present: modern and local meteoric water (48.9%); sub-modern meteoric water from regional highlands precipitation (10.6%); pre-Holocene glaciated meteoric water (40.4%) with strongly depleted δ 2 H values of -127‰, calculated 40 K- 40 Ar* fluid residence times from 57 ± 20 ka to 92 ± 30 ka and a (U/Th)- 4 He fluid residence times from 96 ± 50 ka to 160 ± 80 ka; and, finally, 3 He-rich magmatic fluids. Concomitant enrichment in 18 O and radiogenic 4 He suggests that some fluids reside a long time in the reservoir, exchanging O and He with reservoir rocks. Maximum estimated helium isotopic ratios, 3 He/ 4 He (R), of 11.45 Ra (Ra = atmospheric ratio) show that the magma beneath Theistareykir is a depleted mid-ocean ridge basalt (MORB) mantle (DMM), with less influence (8.7 to 12.7%) of the Icelandic mantle plume source. Calculated heat (Q)/ 3 He ratios plotted vs. R/Ra and 4 He/ 36 Ar ratios suggest that convective heat transport dominates the eastern part of the field where the magmatic heat source is located, while in other parts of the field, heat conduction seems to be dominant. Boiling and phase separation exists in the field, as indicated by δ 18 O values ... Article in Journal/Newspaper Iceland Université de Nantes: HAL-UNIV-NANTES Journal of Volcanology and Geothermal Research 405 107062 |