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Thomas Lebourg - One of the best experts on this subject based on the ideXlab platform.
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Three-Dimensional Electrical Resistivity Tomography of the Solfatara Crater (Italy): Implication for the Multiphase Flow Structure of the Shallow Hydrothermal System
Journal of Geophysical Research : Solid Earth, 2017Co-Authors: Marceau Gresse, Giovanni Chiodini, S. Byrdina, Timothy Johnson, Tullio Ricci, Giuseppe Vilardo, Annarita Mangiacapra, Jean Vandemeulebrouck, André Revil, Thomas LebourgAbstract:The Solfatara volcano is the main degassing area of the Campi Flegrei caldera, characterized by 60 years of unrest. Assessing such renewal activity is a challenging task because hydrothermal interactions with magmatic gases remain poorly understood. In this study, we decipher the complex structure of the shallow Solfatara hydrothermal system by performing the first 3‐D, high‐resolution, electrical Resistivity tomography of the volcano. The 3‐D Resistivity Model was obtained from the inversion of 43,432 resistance measurements performed on an area of ~0.68 km2. The proposed interpretation of the multiphase hydrothermal structures is based on the Resistivity Model, a high‐resolution infrared surface temperature image, and 1,136 soil CO2 flux measurements. In addition, we realized 27 soil cation exchange capacity and pH measurements demonstrating a negligible contribution of surface conductivity to the shallow bulk electrical conductivity. Hence, we show that the Resistivity changes are mainly controlled by fluid content and temperature. The high‐resolution tomograms identify for the first time the structure of the gas‐dominated reservoir at 60 m depth that feeds the Bocca Grande fumarole through a ~10 m thick channel. In addition, the Resistivity Model reveals a channel‐like conductive structure where the liquid produced by steam condensation around the main fumaroles flows down to the Fangaia area within a buried fault. The Model delineates the emplacement of the main geological structures: Mount Olibano, Solfatara cryptodome, and tephra deposits. It also reveals the anatomy of the hydrothermal system, especially two liquid‐dominated plumes, the Fangaia mud pool and the Pisciarelli fumarole, respectively.
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three dimensional electrical Resistivity tomography of the solfatara crater italy implication for the multiphase flow structure of the shallow hydrothermal system
Journal of Geophysical Research, 2017Co-Authors: Marceau Gresse, Giovanni Chiodini, S. Byrdina, Tullio Ricci, Giuseppe Vilardo, Annarita Mangiacapra, Jean Vandemeulebrouck, André Revil, Timothy C Johnson, Thomas LebourgAbstract:The Solfatara volcano is the main degassing area of the Campi Flegrei caldera, characterized by 60 years of unrest. Assessing such renewal activity is a challenging task because hydrothermal interactions with magmatic gases remain poorly understood. In this study, we decipher the complex structure of the shallow Solfatara hydrothermal system by performing the first 3-D, high-resolution, Electrical Resistivity Tomography (ERT) of the volcano. The 3-D Resistivity Model was obtained from the inversion of 43,432 resistance measurements performed on an area of 0.68 km2. The proposed interpretation of the multiphase hydrothermal structures is based on the Resistivity Model, a high-resolution infrared surface temperature image, and 1,136 soil CO2 flux measurements. In addition, we realized 27 soil Cation Exchange Capacity (CEC) and pH measurements demonstrating a negligible contribution of surface conductivity to the shallow bulk electrical conductivity. Hence, we show that the Resistivity changes are mainly controlled by fluid content and temperature. The high-resolution tomograms identify for the first time the structure of the gas-dominated reservoir at 50 m depth that feeds the Bocca Grande fumarole through a ~10-m-thick channel. In addition, the Resistivity Model reveals a channel-like conductive structure where the liquid produced by steam condensation around the main fumaroles flows down to the Fangaia area within a buried fault. The Model delineates the emplacement of the main geological structures: Mt Olibano, Solfatara crypto-dome, and tephra deposits. It also reveals the anatomy of the hydrothermal system, especially two liquid-dominated plumes, the Fangaia mud pool and the Pisciarelli fumarole, respectively.
Makoto Uyeshima - One of the best experts on this subject based on the ideXlab platform.
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magma reservoir beneath azumayama volcano ne japan as inferred from a three dimensional electrical Resistivity Model explored by means of magnetotelluric method
Earth Planets and Space, 2021Co-Authors: Masahiro Ichiki, Toshiki Kaida, Takashi Nakayama, Satoshi Miura, Mare Yamamoto, Yuichi Morita, Makoto UyeshimaAbstract:An electrical Resistivity Model beneath Azumayama Volcano, NE Japan, is explored using magnetotelluric method to probe the magma/hydrothermal fluid distribution. Azumayama is one of the most concerning active volcanoes capable of producing a potential eruption triggered by the 2011 Tohoku-Oki Earthquake. The three-dimensional Resistivity Model reveals a conductive magma reservoir (< 3 Ωm) at depths of 3–15 km below sea level (bsl). The 67% and 90% confidence intervals of Resistivity are 0.2–5 Ωm and 0.02–70 Ωm, respectively, for the magma reservoir. We assumed dacitic melt + rock at a shallow depth of 4 km bsl and andesitic melt + rock at a greater depth of 9 km bsl. The confidence interval of Resistivity cannot be explained by using dacitic melt + rock condition at a depth of 4 km bsl. This suggests that very conductive hydrothermal fluids coexist with dacitic melt and rock in the shallow part of the magma reservoir. For the depth of 9 km bsl, the 67% confidence interval of Resistivity is interpreted as water-saturated (8.0 weight %) andesitic melt–mafic rock complex with melt volume fractions greater than 4 volume %, while the shear wave velocity requires the fluid and/or melt volume fraction of 6–7 volume % at that depth. Considering the fluid and/or melt volume fraction of 6–7 volume %, the conductive hydrous phase is likewise required to explain the wide range of the 67% confidence interval of Resistivity. The Mogi inflation source determined from geodetic data lies on the resistive side near the top boundary of the conductive magma reservoir at a depth of 2.7 or 3.7 km bsl. Assuming that the Resistivity of the inflation source region is above the upper bound of the confidence interval of Resistivity for the conductive magma reservoir and that the source region is composed of hydrothermal fluid + rock, the Resistivity of the source region is explained by a hydrothermal fluid volume fraction below 5 volume %, which is the percolation threshold porosity in an effusive eruption. This indicates that the percolation threshold characterizes the inflation source region.
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Magma reservoir beneath Azumayama Volcano, NE Japan, as inferred from a three-dimensional electrical Resistivity Model explored by means of magnetotelluric method
'Springer Science and Business Media LLC', 2021Co-Authors: Masahiro Ichiki, Toshiki Kaida, Takashi Nakayama, Satoshi Miura, Mare Yamamoto, Yuichi Morita, Makoto UyeshimaAbstract:Abstract An electrical Resistivity Model beneath Azumayama Volcano, NE Japan, is explored using magnetotelluric method to probe the magma/hydrothermal fluid distribution. Azumayama is one of the most concerning active volcanoes capable of producing a potential eruption triggered by the 2011 Tohoku-Oki Earthquake. The three-dimensional Resistivity Model reveals a conductive magma reservoir (
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3 d electrical Resistivity structure based on geomagnetic transfer functions exploring the features of arc magmatism beneath kyushu southwest japan arc
Journal of Geophysical Research, 2017Co-Authors: Makoto Uyeshima, Maki Hata, Shun Handa, Masashi Shimoizumi, Yoshikazu Tanaka, Takeshi Hashimoto, Tsuneomi Kagiyama, Hisashi Utada, Hiroshi MunekaneAbstract:Our 3-D electrical Resistivity Model clearly detects particular subsurface features for magmatism associated with subduction of the Philippine Sea Plate (PSP) in three regions: a southern and a northern volcanic region, and a non-volcanic region on the island of Kyushu. We apply 3-D inversion analyses for geomagnetic transfer function data of a short-period band, in combination with results of a previous 3-D Model that was determined using Network-Magnetotelluric response function data of a longer-period band as an initial Model in the present inversion to improve resolution at shallow depths; specifically, a two-stage inversion is used instead of a joint inversion. In contrast to the previous Model, the presented Model clearly reveals a conductive block on the back-arc side of Kirishima volcano at shallow depths of ~50 km; the block is associated with hydrothermal fluids and hydrothermal alteration zones related to the formation of epithermal gold deposits. A second feature revealed by the Model is another conductive block regarded as upwelling fluids, extending from the upper surface of the PSP in the mantle under Kirishima volcano in the southern volcanic region. Third, a resistive crustal layer, which confines the conductive block in the mantle, is distributed beneath the non-volcanic region. Fourth, our Model reveals a significant resistive block, which extends below the continental Moho at the fore-arc side of the volcanic front and extends into the non-volcanic region in central Kyushu.
Marceau Gresse - One of the best experts on this subject based on the ideXlab platform.
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Three-Dimensional Electrical Resistivity Tomography of the Solfatara Crater (Italy): Implication for the Multiphase Flow Structure of the Shallow Hydrothermal System
Journal of Geophysical Research : Solid Earth, 2017Co-Authors: Marceau Gresse, Giovanni Chiodini, S. Byrdina, Timothy Johnson, Tullio Ricci, Giuseppe Vilardo, Annarita Mangiacapra, Jean Vandemeulebrouck, André Revil, Thomas LebourgAbstract:The Solfatara volcano is the main degassing area of the Campi Flegrei caldera, characterized by 60 years of unrest. Assessing such renewal activity is a challenging task because hydrothermal interactions with magmatic gases remain poorly understood. In this study, we decipher the complex structure of the shallow Solfatara hydrothermal system by performing the first 3‐D, high‐resolution, electrical Resistivity tomography of the volcano. The 3‐D Resistivity Model was obtained from the inversion of 43,432 resistance measurements performed on an area of ~0.68 km2. The proposed interpretation of the multiphase hydrothermal structures is based on the Resistivity Model, a high‐resolution infrared surface temperature image, and 1,136 soil CO2 flux measurements. In addition, we realized 27 soil cation exchange capacity and pH measurements demonstrating a negligible contribution of surface conductivity to the shallow bulk electrical conductivity. Hence, we show that the Resistivity changes are mainly controlled by fluid content and temperature. The high‐resolution tomograms identify for the first time the structure of the gas‐dominated reservoir at 60 m depth that feeds the Bocca Grande fumarole through a ~10 m thick channel. In addition, the Resistivity Model reveals a channel‐like conductive structure where the liquid produced by steam condensation around the main fumaroles flows down to the Fangaia area within a buried fault. The Model delineates the emplacement of the main geological structures: Mount Olibano, Solfatara cryptodome, and tephra deposits. It also reveals the anatomy of the hydrothermal system, especially two liquid‐dominated plumes, the Fangaia mud pool and the Pisciarelli fumarole, respectively.
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three dimensional electrical Resistivity tomography of the solfatara crater italy implication for the multiphase flow structure of the shallow hydrothermal system
Journal of Geophysical Research, 2017Co-Authors: Marceau Gresse, Giovanni Chiodini, S. Byrdina, Tullio Ricci, Giuseppe Vilardo, Annarita Mangiacapra, Jean Vandemeulebrouck, André Revil, Timothy C Johnson, Thomas LebourgAbstract:The Solfatara volcano is the main degassing area of the Campi Flegrei caldera, characterized by 60 years of unrest. Assessing such renewal activity is a challenging task because hydrothermal interactions with magmatic gases remain poorly understood. In this study, we decipher the complex structure of the shallow Solfatara hydrothermal system by performing the first 3-D, high-resolution, Electrical Resistivity Tomography (ERT) of the volcano. The 3-D Resistivity Model was obtained from the inversion of 43,432 resistance measurements performed on an area of 0.68 km2. The proposed interpretation of the multiphase hydrothermal structures is based on the Resistivity Model, a high-resolution infrared surface temperature image, and 1,136 soil CO2 flux measurements. In addition, we realized 27 soil Cation Exchange Capacity (CEC) and pH measurements demonstrating a negligible contribution of surface conductivity to the shallow bulk electrical conductivity. Hence, we show that the Resistivity changes are mainly controlled by fluid content and temperature. The high-resolution tomograms identify for the first time the structure of the gas-dominated reservoir at 50 m depth that feeds the Bocca Grande fumarole through a ~10-m-thick channel. In addition, the Resistivity Model reveals a channel-like conductive structure where the liquid produced by steam condensation around the main fumaroles flows down to the Fangaia area within a buried fault. The Model delineates the emplacement of the main geological structures: Mt Olibano, Solfatara crypto-dome, and tephra deposits. It also reveals the anatomy of the hydrothermal system, especially two liquid-dominated plumes, the Fangaia mud pool and the Pisciarelli fumarole, respectively.
Giovanni Chiodini - One of the best experts on this subject based on the ideXlab platform.
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Three-Dimensional Electrical Resistivity Tomography of the Solfatara Crater (Italy): Implication for the Multiphase Flow Structure of the Shallow Hydrothermal System
Journal of Geophysical Research : Solid Earth, 2017Co-Authors: Marceau Gresse, Giovanni Chiodini, S. Byrdina, Timothy Johnson, Tullio Ricci, Giuseppe Vilardo, Annarita Mangiacapra, Jean Vandemeulebrouck, André Revil, Thomas LebourgAbstract:The Solfatara volcano is the main degassing area of the Campi Flegrei caldera, characterized by 60 years of unrest. Assessing such renewal activity is a challenging task because hydrothermal interactions with magmatic gases remain poorly understood. In this study, we decipher the complex structure of the shallow Solfatara hydrothermal system by performing the first 3‐D, high‐resolution, electrical Resistivity tomography of the volcano. The 3‐D Resistivity Model was obtained from the inversion of 43,432 resistance measurements performed on an area of ~0.68 km2. The proposed interpretation of the multiphase hydrothermal structures is based on the Resistivity Model, a high‐resolution infrared surface temperature image, and 1,136 soil CO2 flux measurements. In addition, we realized 27 soil cation exchange capacity and pH measurements demonstrating a negligible contribution of surface conductivity to the shallow bulk electrical conductivity. Hence, we show that the Resistivity changes are mainly controlled by fluid content and temperature. The high‐resolution tomograms identify for the first time the structure of the gas‐dominated reservoir at 60 m depth that feeds the Bocca Grande fumarole through a ~10 m thick channel. In addition, the Resistivity Model reveals a channel‐like conductive structure where the liquid produced by steam condensation around the main fumaroles flows down to the Fangaia area within a buried fault. The Model delineates the emplacement of the main geological structures: Mount Olibano, Solfatara cryptodome, and tephra deposits. It also reveals the anatomy of the hydrothermal system, especially two liquid‐dominated plumes, the Fangaia mud pool and the Pisciarelli fumarole, respectively.
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three dimensional electrical Resistivity tomography of the solfatara crater italy implication for the multiphase flow structure of the shallow hydrothermal system
Journal of Geophysical Research, 2017Co-Authors: Marceau Gresse, Giovanni Chiodini, S. Byrdina, Tullio Ricci, Giuseppe Vilardo, Annarita Mangiacapra, Jean Vandemeulebrouck, André Revil, Timothy C Johnson, Thomas LebourgAbstract:The Solfatara volcano is the main degassing area of the Campi Flegrei caldera, characterized by 60 years of unrest. Assessing such renewal activity is a challenging task because hydrothermal interactions with magmatic gases remain poorly understood. In this study, we decipher the complex structure of the shallow Solfatara hydrothermal system by performing the first 3-D, high-resolution, Electrical Resistivity Tomography (ERT) of the volcano. The 3-D Resistivity Model was obtained from the inversion of 43,432 resistance measurements performed on an area of 0.68 km2. The proposed interpretation of the multiphase hydrothermal structures is based on the Resistivity Model, a high-resolution infrared surface temperature image, and 1,136 soil CO2 flux measurements. In addition, we realized 27 soil Cation Exchange Capacity (CEC) and pH measurements demonstrating a negligible contribution of surface conductivity to the shallow bulk electrical conductivity. Hence, we show that the Resistivity changes are mainly controlled by fluid content and temperature. The high-resolution tomograms identify for the first time the structure of the gas-dominated reservoir at 50 m depth that feeds the Bocca Grande fumarole through a ~10-m-thick channel. In addition, the Resistivity Model reveals a channel-like conductive structure where the liquid produced by steam condensation around the main fumaroles flows down to the Fangaia area within a buried fault. The Model delineates the emplacement of the main geological structures: Mt Olibano, Solfatara crypto-dome, and tephra deposits. It also reveals the anatomy of the hydrothermal system, especially two liquid-dominated plumes, the Fangaia mud pool and the Pisciarelli fumarole, respectively.
André Revil - One of the best experts on this subject based on the ideXlab platform.
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Three-Dimensional Electrical Resistivity Tomography of the Solfatara Crater (Italy): Implication for the Multiphase Flow Structure of the Shallow Hydrothermal System
Journal of Geophysical Research : Solid Earth, 2017Co-Authors: Marceau Gresse, Giovanni Chiodini, S. Byrdina, Timothy Johnson, Tullio Ricci, Giuseppe Vilardo, Annarita Mangiacapra, Jean Vandemeulebrouck, André Revil, Thomas LebourgAbstract:The Solfatara volcano is the main degassing area of the Campi Flegrei caldera, characterized by 60 years of unrest. Assessing such renewal activity is a challenging task because hydrothermal interactions with magmatic gases remain poorly understood. In this study, we decipher the complex structure of the shallow Solfatara hydrothermal system by performing the first 3‐D, high‐resolution, electrical Resistivity tomography of the volcano. The 3‐D Resistivity Model was obtained from the inversion of 43,432 resistance measurements performed on an area of ~0.68 km2. The proposed interpretation of the multiphase hydrothermal structures is based on the Resistivity Model, a high‐resolution infrared surface temperature image, and 1,136 soil CO2 flux measurements. In addition, we realized 27 soil cation exchange capacity and pH measurements demonstrating a negligible contribution of surface conductivity to the shallow bulk electrical conductivity. Hence, we show that the Resistivity changes are mainly controlled by fluid content and temperature. The high‐resolution tomograms identify for the first time the structure of the gas‐dominated reservoir at 60 m depth that feeds the Bocca Grande fumarole through a ~10 m thick channel. In addition, the Resistivity Model reveals a channel‐like conductive structure where the liquid produced by steam condensation around the main fumaroles flows down to the Fangaia area within a buried fault. The Model delineates the emplacement of the main geological structures: Mount Olibano, Solfatara cryptodome, and tephra deposits. It also reveals the anatomy of the hydrothermal system, especially two liquid‐dominated plumes, the Fangaia mud pool and the Pisciarelli fumarole, respectively.
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three dimensional electrical Resistivity tomography of the solfatara crater italy implication for the multiphase flow structure of the shallow hydrothermal system
Journal of Geophysical Research, 2017Co-Authors: Marceau Gresse, Giovanni Chiodini, S. Byrdina, Tullio Ricci, Giuseppe Vilardo, Annarita Mangiacapra, Jean Vandemeulebrouck, André Revil, Timothy C Johnson, Thomas LebourgAbstract:The Solfatara volcano is the main degassing area of the Campi Flegrei caldera, characterized by 60 years of unrest. Assessing such renewal activity is a challenging task because hydrothermal interactions with magmatic gases remain poorly understood. In this study, we decipher the complex structure of the shallow Solfatara hydrothermal system by performing the first 3-D, high-resolution, Electrical Resistivity Tomography (ERT) of the volcano. The 3-D Resistivity Model was obtained from the inversion of 43,432 resistance measurements performed on an area of 0.68 km2. The proposed interpretation of the multiphase hydrothermal structures is based on the Resistivity Model, a high-resolution infrared surface temperature image, and 1,136 soil CO2 flux measurements. In addition, we realized 27 soil Cation Exchange Capacity (CEC) and pH measurements demonstrating a negligible contribution of surface conductivity to the shallow bulk electrical conductivity. Hence, we show that the Resistivity changes are mainly controlled by fluid content and temperature. The high-resolution tomograms identify for the first time the structure of the gas-dominated reservoir at 50 m depth that feeds the Bocca Grande fumarole through a ~10-m-thick channel. In addition, the Resistivity Model reveals a channel-like conductive structure where the liquid produced by steam condensation around the main fumaroles flows down to the Fangaia area within a buried fault. The Model delineates the emplacement of the main geological structures: Mt Olibano, Solfatara crypto-dome, and tephra deposits. It also reveals the anatomy of the hydrothermal system, especially two liquid-dominated plumes, the Fangaia mud pool and the Pisciarelli fumarole, respectively.