Excess Po-210 in 2010 Eyjatjallajokull tephra (Iceland): Evidence for pre-eruptive gas accumulation
International audience Excess gas phase in magmas erupting explosively is well known worldwide. However, the origin of this gas phase, in excess of what can be dissolved in the erupting magma at depth, and the rate of gas accumulation is less well defined. The 2010 mildly explosive eruption at Eyjaf...
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ftinsu:oai:HAL:hal-01217142v1 2023-06-18T03:40:32+02:00 Excess Po-210 in 2010 Eyjatjallajokull tephra (Iceland): Evidence for pre-eruptive gas accumulation Sigmarsson, Olgeir Condomines, Michel Gauthier, Pierre-Jean Laboratoire Magmas et Volcans (LMV) Observatoire de Physique du Globe de Clermont-Ferrand (OPGC) Université Blaise Pascal - Clermont-Ferrand 2 (UBP)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS)-Université Blaise Pascal - Clermont-Ferrand 2 (UBP)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS)-Université Jean Monnet - Saint-Étienne (UJM)-Centre National de la Recherche Scientifique (CNRS) Géosciences Montpellier Institut national des sciences de l'Univers (INSU - CNRS)-Université de Montpellier (UM)-Centre National de la Recherche Scientifique (CNRS)-Université des Antilles (UA) 2015-10-01 https://hal.science/hal-01217142 https://doi.org/10.1016/j.epsl.2015.06.054 en eng HAL CCSD Elsevier info:eu-repo/semantics/altIdentifier/doi/10.1016/j.epsl.2015.06.054 hal-01217142 https://hal.science/hal-01217142 doi:10.1016/j.epsl.2015.06.054 ISSN: 0012-821X Earth and Planetary Science Letters https://hal.science/hal-01217142 Earth and Planetary Science Letters, 2015, 427, pp.66-73. ⟨10.1016/j.epsl.2015.06.054⟩ polonium radon degassing accumulation in magmas Po-210-Pb-210-Ra-226 disequilibria free vapour phase closed-open system degassing Eyjafjallajokull volcano [SDU.STU.GC]Sciences of the Universe [physics]/Earth Sciences/Geochemistry info:eu-repo/semantics/article Journal articles 2015 ftinsu https://doi.org/10.1016/j.epsl.2015.06.054 2023-06-06T01:14:51Z International audience Excess gas phase in magmas erupting explosively is well known worldwide. However, the origin of this gas phase, in excess of what can be dissolved in the erupting magma at depth, and the rate of gas accumulation is less well defined. The 2010 mildly explosive eruption at Eyjafjallajökull, Iceland, produced mingled tephra of benmoreitic and trachytic composition whereas alkali basalt was emitted during preceding flank eruption. Tephra of the first explosive phase are composed of three glass types, alkaline rhyolite, mixed benmoreite, and basalt, which suggests that the basaltic magma intruded a pre-existing rhyolitic magma chamber, and ultimately triggered the eruption. The mixed benmoreitic tephra (erupted on 15 and 17 April 2010) had large 210Po in excess of 210Pb View the MathML source[(Po210/Pb210)0=1.88] at the time of eruption, and possibly a small 210Pb excess over its parent 226Ra. In contrast, the preceding flank eruption produced basalt with View the MathML source(Po210)0=0, upon eruption, and the final trachyte had lost most of its 210Po during open-system degassing. The 210Po excess in the first erupted benmoreites is interpreted to result from 210Po degassing of basaltic magma and the accumulation of 210Po-enriched gas, either in the upper part of the basaltic intrusion, below the rhyolite–basalt interface, or in the pre-existing residual rhyolitic magma chamber. From a simple model of radon and polonium accumulation in the rhyolitic reservoir, the ratio of the mass of basalt magma degassing over the mass of magma accumulating the excess gas decreased from 20 to 15 over 2 days, implying zoned magma reservoir, with the uppermost and gas-richest part erupting first. The duration of pre-eruptive gas accumulation in this model is approximately one year. This corresponds closely to the initiation of a seismic swarm beneath Eyjafjallajökull, early June 2009, which was the first pre-eruptive signal detected. The coincidence between initiation of gas accumulation at relatively ... Article in Journal/Newspaper Eyjafjallajökull Iceland Institut national des sciences de l'Univers: HAL-INSU Eyjafjallajokull ENVELOPE(-19.633,-19.633,63.631,63.631) Earth and Planetary Science Letters 427 66 73 |
institution |
Open Polar |
collection |
Institut national des sciences de l'Univers: HAL-INSU |
op_collection_id |
ftinsu |
language |
English |
topic |
polonium radon degassing accumulation in magmas Po-210-Pb-210-Ra-226 disequilibria free vapour phase closed-open system degassing Eyjafjallajokull volcano [SDU.STU.GC]Sciences of the Universe [physics]/Earth Sciences/Geochemistry |
spellingShingle |
polonium radon degassing accumulation in magmas Po-210-Pb-210-Ra-226 disequilibria free vapour phase closed-open system degassing Eyjafjallajokull volcano [SDU.STU.GC]Sciences of the Universe [physics]/Earth Sciences/Geochemistry Sigmarsson, Olgeir Condomines, Michel Gauthier, Pierre-Jean Excess Po-210 in 2010 Eyjatjallajokull tephra (Iceland): Evidence for pre-eruptive gas accumulation |
topic_facet |
polonium radon degassing accumulation in magmas Po-210-Pb-210-Ra-226 disequilibria free vapour phase closed-open system degassing Eyjafjallajokull volcano [SDU.STU.GC]Sciences of the Universe [physics]/Earth Sciences/Geochemistry |
description |
International audience Excess gas phase in magmas erupting explosively is well known worldwide. However, the origin of this gas phase, in excess of what can be dissolved in the erupting magma at depth, and the rate of gas accumulation is less well defined. The 2010 mildly explosive eruption at Eyjafjallajökull, Iceland, produced mingled tephra of benmoreitic and trachytic composition whereas alkali basalt was emitted during preceding flank eruption. Tephra of the first explosive phase are composed of three glass types, alkaline rhyolite, mixed benmoreite, and basalt, which suggests that the basaltic magma intruded a pre-existing rhyolitic magma chamber, and ultimately triggered the eruption. The mixed benmoreitic tephra (erupted on 15 and 17 April 2010) had large 210Po in excess of 210Pb View the MathML source[(Po210/Pb210)0=1.88] at the time of eruption, and possibly a small 210Pb excess over its parent 226Ra. In contrast, the preceding flank eruption produced basalt with View the MathML source(Po210)0=0, upon eruption, and the final trachyte had lost most of its 210Po during open-system degassing. The 210Po excess in the first erupted benmoreites is interpreted to result from 210Po degassing of basaltic magma and the accumulation of 210Po-enriched gas, either in the upper part of the basaltic intrusion, below the rhyolite–basalt interface, or in the pre-existing residual rhyolitic magma chamber. From a simple model of radon and polonium accumulation in the rhyolitic reservoir, the ratio of the mass of basalt magma degassing over the mass of magma accumulating the excess gas decreased from 20 to 15 over 2 days, implying zoned magma reservoir, with the uppermost and gas-richest part erupting first. The duration of pre-eruptive gas accumulation in this model is approximately one year. This corresponds closely to the initiation of a seismic swarm beneath Eyjafjallajökull, early June 2009, which was the first pre-eruptive signal detected. The coincidence between initiation of gas accumulation at relatively ... |
author2 |
Laboratoire Magmas et Volcans (LMV) Observatoire de Physique du Globe de Clermont-Ferrand (OPGC) Université Blaise Pascal - Clermont-Ferrand 2 (UBP)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS)-Université Blaise Pascal - Clermont-Ferrand 2 (UBP)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS)-Université Jean Monnet - Saint-Étienne (UJM)-Centre National de la Recherche Scientifique (CNRS) Géosciences Montpellier Institut national des sciences de l'Univers (INSU - CNRS)-Université de Montpellier (UM)-Centre National de la Recherche Scientifique (CNRS)-Université des Antilles (UA) |
format |
Article in Journal/Newspaper |
author |
Sigmarsson, Olgeir Condomines, Michel Gauthier, Pierre-Jean |
author_facet |
Sigmarsson, Olgeir Condomines, Michel Gauthier, Pierre-Jean |
author_sort |
Sigmarsson, Olgeir |
title |
Excess Po-210 in 2010 Eyjatjallajokull tephra (Iceland): Evidence for pre-eruptive gas accumulation |
title_short |
Excess Po-210 in 2010 Eyjatjallajokull tephra (Iceland): Evidence for pre-eruptive gas accumulation |
title_full |
Excess Po-210 in 2010 Eyjatjallajokull tephra (Iceland): Evidence for pre-eruptive gas accumulation |
title_fullStr |
Excess Po-210 in 2010 Eyjatjallajokull tephra (Iceland): Evidence for pre-eruptive gas accumulation |
title_full_unstemmed |
Excess Po-210 in 2010 Eyjatjallajokull tephra (Iceland): Evidence for pre-eruptive gas accumulation |
title_sort |
excess po-210 in 2010 eyjatjallajokull tephra (iceland): evidence for pre-eruptive gas accumulation |
publisher |
HAL CCSD |
publishDate |
2015 |
url |
https://hal.science/hal-01217142 https://doi.org/10.1016/j.epsl.2015.06.054 |
long_lat |
ENVELOPE(-19.633,-19.633,63.631,63.631) |
geographic |
Eyjafjallajokull |
geographic_facet |
Eyjafjallajokull |
genre |
Eyjafjallajökull Iceland |
genre_facet |
Eyjafjallajökull Iceland |
op_source |
ISSN: 0012-821X Earth and Planetary Science Letters https://hal.science/hal-01217142 Earth and Planetary Science Letters, 2015, 427, pp.66-73. ⟨10.1016/j.epsl.2015.06.054⟩ |
op_relation |
info:eu-repo/semantics/altIdentifier/doi/10.1016/j.epsl.2015.06.054 hal-01217142 https://hal.science/hal-01217142 doi:10.1016/j.epsl.2015.06.054 |
op_doi |
https://doi.org/10.1016/j.epsl.2015.06.054 |
container_title |
Earth and Planetary Science Letters |
container_volume |
427 |
container_start_page |
66 |
op_container_end_page |
73 |
_version_ |
1769005693375873024 |