Hybrid Microgravity Monitoring of the Theistareykir Geothermal Reservoir (North Iceland)

The Theistareykir geothermal field is located in North Iceland on the Mid-Atlantic ridge. A power plant produces 90 MWe using two 45 MWe turbines in operation since autumn 2017 and spring 2018, respectively. We performed hybrid microgravity measurements from 2017 to 2019 to monitor the short-term ma...

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Published in:Pure and Applied Geophysics
Main Authors: Portier, N., Forster, F., Hinderer, J., Erbas, K., Jousset, P., Drouin, V., Li, S., Sigmundsson, F., Magnússon, I., Hersir, G., Ágústsson, K., Guðmundsson, Á., Júlíusson, E., Hjartasson, H., Bernard, J.
Format: Article in Journal/Newspaper
Language:unknown
Published: 2022
Subjects:
Online Access:https://gfzpublic.gfz-potsdam.de/pubman/item/item_5011910
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spelling ftgfzpotsdam:oai:gfzpublic.gfz-potsdam.de:item_5011910 2023-05-15T16:48:23+02:00 Hybrid Microgravity Monitoring of the Theistareykir Geothermal Reservoir (North Iceland) Portier, N. Forster, F. Hinderer, J. Erbas, K. Jousset, P. Drouin, V. Li, S. Sigmundsson, F. Magnússon, I. Hersir, G. Ágústsson, K. Guðmundsson, Á. Júlíusson, E. Hjartasson, H. Bernard, J. 2022 https://gfzpublic.gfz-potsdam.de/pubman/item/item_5011910 unknown info:eu-repo/semantics/altIdentifier/doi/10.1007/s00024-022-03018-8 https://gfzpublic.gfz-potsdam.de/pubman/item/item_5011910 Pure and Applied Geophysics info:eu-repo/semantics/article 2022 ftgfzpotsdam https://doi.org/10.1007/s00024-022-03018-8 2022-09-14T05:58:18Z The Theistareykir geothermal field is located in North Iceland on the Mid-Atlantic ridge. A power plant produces 90 MWe using two 45 MWe turbines in operation since autumn 2017 and spring 2018, respectively. We performed hybrid microgravity measurements from 2017 to 2019 to monitor the short-term mass redistribution induced by geothermal production. Time-lapse microgravity surveys conducted each summer with a Scintrex CG5 gravimeter reveal the spatial gravity variations with respect to a reference, where the temporal gravity changes are monitored by absolute gravity measurements done with FG5#206 from Micro-g Solutions. In parallel, continuous gravity changes are recorded by a network of several GWR Instruments iGrav superconducting gravimeters and spring gravimeter, located in the injection and production areas. A height correction is applied to the gravity data using InSAR and GNSS measurements. We notice a regular residual gravity decrease in the production area versus a stable behaviour in the injection area. Time-lapse gravity measurements reveal a minimum residual decrease of − 38 ± 10 µGal (1 µGal = 10–8 m s−2) in 2019 with respect to 2017. Simplistic forward modelling of the produced geothermal fluid using a multiple Mogi sphere model can partly explain the residual gravity decrease. This suggest that a significant part of the injected geothermal fluid flows away, maybe drained by the Tjarnarás fault to the South where an increase of the water table level is observed. However, further modelling work is needed to confirm this. Article in Journal/Newspaper Iceland GFZpublic (German Research Centre for Geosciences, Helmholtz-Zentrum Potsdam) Mid-Atlantic Ridge Pure and Applied Geophysics
institution Open Polar
collection GFZpublic (German Research Centre for Geosciences, Helmholtz-Zentrum Potsdam)
op_collection_id ftgfzpotsdam
language unknown
description The Theistareykir geothermal field is located in North Iceland on the Mid-Atlantic ridge. A power plant produces 90 MWe using two 45 MWe turbines in operation since autumn 2017 and spring 2018, respectively. We performed hybrid microgravity measurements from 2017 to 2019 to monitor the short-term mass redistribution induced by geothermal production. Time-lapse microgravity surveys conducted each summer with a Scintrex CG5 gravimeter reveal the spatial gravity variations with respect to a reference, where the temporal gravity changes are monitored by absolute gravity measurements done with FG5#206 from Micro-g Solutions. In parallel, continuous gravity changes are recorded by a network of several GWR Instruments iGrav superconducting gravimeters and spring gravimeter, located in the injection and production areas. A height correction is applied to the gravity data using InSAR and GNSS measurements. We notice a regular residual gravity decrease in the production area versus a stable behaviour in the injection area. Time-lapse gravity measurements reveal a minimum residual decrease of − 38 ± 10 µGal (1 µGal = 10–8 m s−2) in 2019 with respect to 2017. Simplistic forward modelling of the produced geothermal fluid using a multiple Mogi sphere model can partly explain the residual gravity decrease. This suggest that a significant part of the injected geothermal fluid flows away, maybe drained by the Tjarnarás fault to the South where an increase of the water table level is observed. However, further modelling work is needed to confirm this.
format Article in Journal/Newspaper
author Portier, N.
Forster, F.
Hinderer, J.
Erbas, K.
Jousset, P.
Drouin, V.
Li, S.
Sigmundsson, F.
Magnússon, I.
Hersir, G.
Ágústsson, K.
Guðmundsson, Á.
Júlíusson, E.
Hjartasson, H.
Bernard, J.
spellingShingle Portier, N.
Forster, F.
Hinderer, J.
Erbas, K.
Jousset, P.
Drouin, V.
Li, S.
Sigmundsson, F.
Magnússon, I.
Hersir, G.
Ágústsson, K.
Guðmundsson, Á.
Júlíusson, E.
Hjartasson, H.
Bernard, J.
Hybrid Microgravity Monitoring of the Theistareykir Geothermal Reservoir (North Iceland)
author_facet Portier, N.
Forster, F.
Hinderer, J.
Erbas, K.
Jousset, P.
Drouin, V.
Li, S.
Sigmundsson, F.
Magnússon, I.
Hersir, G.
Ágústsson, K.
Guðmundsson, Á.
Júlíusson, E.
Hjartasson, H.
Bernard, J.
author_sort Portier, N.
title Hybrid Microgravity Monitoring of the Theistareykir Geothermal Reservoir (North Iceland)
title_short Hybrid Microgravity Monitoring of the Theistareykir Geothermal Reservoir (North Iceland)
title_full Hybrid Microgravity Monitoring of the Theistareykir Geothermal Reservoir (North Iceland)
title_fullStr Hybrid Microgravity Monitoring of the Theistareykir Geothermal Reservoir (North Iceland)
title_full_unstemmed Hybrid Microgravity Monitoring of the Theistareykir Geothermal Reservoir (North Iceland)
title_sort hybrid microgravity monitoring of the theistareykir geothermal reservoir (north iceland)
publishDate 2022
url https://gfzpublic.gfz-potsdam.de/pubman/item/item_5011910
geographic Mid-Atlantic Ridge
geographic_facet Mid-Atlantic Ridge
genre Iceland
genre_facet Iceland
op_source Pure and Applied Geophysics
op_relation info:eu-repo/semantics/altIdentifier/doi/10.1007/s00024-022-03018-8
https://gfzpublic.gfz-potsdam.de/pubman/item/item_5011910
op_doi https://doi.org/10.1007/s00024-022-03018-8
container_title Pure and Applied Geophysics
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