Time variations in the chemical and isotopic composition of fumarolic gases at Hakone volcano, Honshu Island, Japan, over the earthquake swarm and eruption in 2015, interpreted by magma sealing model
Abstract Definite increases in the components ratios of CO2/H2O, CO2/H2S, CO2/CH4 and He/CH4 were observed at the fumarolic gases from Owakudani geothermal area located at the center of Hakone volcanic caldera (Honshu Island, Japan), synchronized with the earthquake swarm in 2015. Such variations we...
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| Format: | Article |
| Language: | English |
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SpringerOpen
2019-04-01
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| Series: | Earth, Planets and Space |
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| Online Access: | http://link.springer.com/article/10.1186/s40623-019-1027-5 |
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| author | Takeshi Ohba Muga Yaguchi Kana Nishino Nozomi Numanami Yasushi Daita Chiho Sukigara Masanori Ito Urumu Tsunogai |
| author_facet | Takeshi Ohba Muga Yaguchi Kana Nishino Nozomi Numanami Yasushi Daita Chiho Sukigara Masanori Ito Urumu Tsunogai |
| author_sort | Takeshi Ohba |
| collection | DOAJ |
| description | Abstract Definite increases in the components ratios of CO2/H2O, CO2/H2S, CO2/CH4 and He/CH4 were observed at the fumarolic gases from Owakudani geothermal area located at the center of Hakone volcanic caldera (Honshu Island, Japan), synchronized with the earthquake swarm in 2015. Such variations were due to the dominance of a magmatic component over a hydrothermal component, suggesting the earthquake swarm was produced by the injection of magmatic gases into the hydrothermal system. The CO2/H2O ratio of magmatic gas was estimated to be 0.0045 before the earthquake swarm, which increased up to 0.013 during the earthquake swarm, likely produced by the pressurization of magma as a result of magma sealing where the pressure increment in magma was estimated to be 3% to the lithostatic pressure. The H2O and CO2 concentration in magma were estimated to be 6.3 wt% and 20 wt ppm, respectively, assuming a temperature 900 °C and a rhyolitic composition. In May 2015, a few months prior to the earthquake swarm in May 2015, a sharp increase in the Ar/CO2 and N2/He ratios and a decrease in the isotopic ratio of H2O were observed at the fumarolic gas. The invasion of air into the hydrothermal system increased the Ar/CO2 and N2/He ratios. The decrease in the isotopic ratio of H2O was induced by partial condensation of H2O vapor. |
| first_indexed | 2024-12-17T10:54:24Z |
| format | Article |
| id | doaj.art-55c26b12e0c54f0ebe94d090cface691 |
| institution | Directory Open Access Journal |
| issn | 1880-5981 |
| language | English |
| last_indexed | 2024-12-17T10:54:24Z |
| publishDate | 2019-04-01 |
| publisher | SpringerOpen |
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| series | Earth, Planets and Space |
| spelling | doaj.art-55c26b12e0c54f0ebe94d090cface6912022-12-21T21:51:53ZengSpringerOpenEarth, Planets and Space1880-59812019-04-0171111810.1186/s40623-019-1027-5Time variations in the chemical and isotopic composition of fumarolic gases at Hakone volcano, Honshu Island, Japan, over the earthquake swarm and eruption in 2015, interpreted by magma sealing modelTakeshi Ohba0Muga Yaguchi1Kana Nishino2Nozomi Numanami3Yasushi Daita4Chiho Sukigara5Masanori Ito6Urumu Tsunogai7Tokai UniversityMeteorological Research InstituteTokai UniversityTokai UniversityKanagawa Environmental Research CenterGraduate School of Environmental Studies, Nagoya UniversityGraduate School of Environmental Studies, Nagoya UniversityGraduate School of Environmental Studies, Nagoya UniversityAbstract Definite increases in the components ratios of CO2/H2O, CO2/H2S, CO2/CH4 and He/CH4 were observed at the fumarolic gases from Owakudani geothermal area located at the center of Hakone volcanic caldera (Honshu Island, Japan), synchronized with the earthquake swarm in 2015. Such variations were due to the dominance of a magmatic component over a hydrothermal component, suggesting the earthquake swarm was produced by the injection of magmatic gases into the hydrothermal system. The CO2/H2O ratio of magmatic gas was estimated to be 0.0045 before the earthquake swarm, which increased up to 0.013 during the earthquake swarm, likely produced by the pressurization of magma as a result of magma sealing where the pressure increment in magma was estimated to be 3% to the lithostatic pressure. The H2O and CO2 concentration in magma were estimated to be 6.3 wt% and 20 wt ppm, respectively, assuming a temperature 900 °C and a rhyolitic composition. In May 2015, a few months prior to the earthquake swarm in May 2015, a sharp increase in the Ar/CO2 and N2/He ratios and a decrease in the isotopic ratio of H2O were observed at the fumarolic gas. The invasion of air into the hydrothermal system increased the Ar/CO2 and N2/He ratios. The decrease in the isotopic ratio of H2O was induced by partial condensation of H2O vapor.http://link.springer.com/article/10.1186/s40623-019-1027-5Active volcanoFumarolic gasEarthquake swarmPhreatic eruptionMt. HakoneMagma degassing |
| spellingShingle | Takeshi Ohba Muga Yaguchi Kana Nishino Nozomi Numanami Yasushi Daita Chiho Sukigara Masanori Ito Urumu Tsunogai Time variations in the chemical and isotopic composition of fumarolic gases at Hakone volcano, Honshu Island, Japan, over the earthquake swarm and eruption in 2015, interpreted by magma sealing model Earth, Planets and Space Active volcano Fumarolic gas Earthquake swarm Phreatic eruption Mt. Hakone Magma degassing |
| title | Time variations in the chemical and isotopic composition of fumarolic gases at Hakone volcano, Honshu Island, Japan, over the earthquake swarm and eruption in 2015, interpreted by magma sealing model |
| title_full | Time variations in the chemical and isotopic composition of fumarolic gases at Hakone volcano, Honshu Island, Japan, over the earthquake swarm and eruption in 2015, interpreted by magma sealing model |
| title_fullStr | Time variations in the chemical and isotopic composition of fumarolic gases at Hakone volcano, Honshu Island, Japan, over the earthquake swarm and eruption in 2015, interpreted by magma sealing model |
| title_full_unstemmed | Time variations in the chemical and isotopic composition of fumarolic gases at Hakone volcano, Honshu Island, Japan, over the earthquake swarm and eruption in 2015, interpreted by magma sealing model |
| title_short | Time variations in the chemical and isotopic composition of fumarolic gases at Hakone volcano, Honshu Island, Japan, over the earthquake swarm and eruption in 2015, interpreted by magma sealing model |
| title_sort | time variations in the chemical and isotopic composition of fumarolic gases at hakone volcano honshu island japan over the earthquake swarm and eruption in 2015 interpreted by magma sealing model |
| topic | Active volcano Fumarolic gas Earthquake swarm Phreatic eruption Mt. Hakone Magma degassing |
| url | http://link.springer.com/article/10.1186/s40623-019-1027-5 |
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