Volcano-tectonic interactions revealed by inversion of focal mechanisms: stress field insight around and beneath the Vatnajökull ice cape in Iceland
International audience Volcano-tectonic processes in the central part of Iceland, covered by the Vatnajökull glacier, are investigated by inversion of focal mechanisms. Working on a large catalog of focal mechanisms determined by the Icelandic Meteorological Office (IMO), we used a damped regional-s...
Published in: | Frontiers in Earth Science |
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Format: | Article in Journal/Newspaper |
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Online Access: | https://hal.science/hal-01452950 https://hal.science/hal-01452950/document https://hal.science/hal-01452950/file/feart-02-00009.pdf https://doi.org/10.3389/feart.2014.00009 |
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ftsorbonneuniv:oai:HAL:hal-01452950v1 2023-12-17T10:30:33+01:00 Volcano-tectonic interactions revealed by inversion of focal mechanisms: stress field insight around and beneath the Vatnajökull ice cape in Iceland Plateaux, Romain Béthoux, Nicole Bergerat, Françoise Mercier de Lépinay, Bernard Institute of Oceanography Taipei National Taiwan University Taiwan (NTU) Géoazur (GEOAZUR 6526) Institut de Recherche pour le Développement (IRD)-Université Pierre et Marie Curie - Paris 6 (UPMC)-Université Nice Sophia Antipolis (1965 - 2019) (UNS)-Institut national des sciences de l'Univers (INSU - CNRS)-Observatoire de la Côte d'Azur Université Côte d'Azur (UCA)-Université Côte d'Azur (UCA)-Centre National de la Recherche Scientifique (CNRS) Institut des Sciences de la Terre de Paris (iSTeP) Université Pierre et Marie Curie - Paris 6 (UPMC)-Centre National de la Recherche Scientifique (CNRS) 2014 https://hal.science/hal-01452950 https://hal.science/hal-01452950/document https://hal.science/hal-01452950/file/feart-02-00009.pdf https://doi.org/10.3389/feart.2014.00009 en eng HAL CCSD Frontiers Media info:eu-repo/semantics/altIdentifier/doi/10.3389/feart.2014.00009 hal-01452950 https://hal.science/hal-01452950 https://hal.science/hal-01452950/document https://hal.science/hal-01452950/file/feart-02-00009.pdf doi:10.3389/feart.2014.00009 http://creativecommons.org/licenses/by-nc/ info:eu-repo/semantics/OpenAccess ISSN: 2296-6463 Frontiers in Earth Science https://hal.science/hal-01452950 Frontiers in Earth Science, 2014, 2, pp.9. ⟨10.3389/feart.2014.00009⟩ seismotectonics mid-ocean ridges volcano-tectonic interactions focal mechanisms Stress inversion slow spreading ridges Icelandic hot-spot [SDU.STU]Sciences of the Universe [physics]/Earth Sciences info:eu-repo/semantics/article Journal articles 2014 ftsorbonneuniv https://doi.org/10.3389/feart.2014.00009 2023-11-21T23:48:03Z International audience Volcano-tectonic processes in the central part of Iceland, covered by the Vatnajökull glacier, are investigated by inversion of focal mechanisms. Working on a large catalog of focal mechanisms determined by the Icelandic Meteorological Office (IMO), we used a damped regional-scale stress inversion method to obtain an insight of kilometric variations of the stress field. To evaluate the resolution and the stability of this stress field solution, we computed checkerboard tests, stress field models and error propagation tests. Stress field models showed a continuous stress regime between normal and strike-slip faulting, associated with a high stress shape ratio (i.e., σ 1 ≈ σ 2). Two main directions of σ hmin were evidenced: the first one was in agreement with the regional spreading direction of Iceland and the second one was deviated, being almost perpendicular to the first one. The deviated stress direction is sustained through the 20 year time-span of the study around the Bárðarbunga and Grimsvötn central volcanoes while the spreading direction remains predominant around the Hamarinn volcano. This result supports the hypothesis that this volcano lacks collapse caldera and shares a fissure swarm with the larger Bárðarbunga volcano. On a smaller temporal scale, during the 1996 volcanic crisis, a bimodal distribution of σ hmin showed two opposite strike-slip regimes where the deviated direction dominated. Because these two states of stress T1 and T2 show stress regimes away from the Andersonian positions, P, B, and T axes, the rapid flip between these two regimes may be associated with the progressive melt intrusion of a dyke. Article in Journal/Newspaper glacier Iceland Vatnajökull HAL Sorbonne Université Hamarinn ENVELOPE(-17.832,-17.832,64.480,64.480) Vatnajökull ENVELOPE(-16.823,-16.823,64.420,64.420) Frontiers in Earth Science 2 |
institution |
Open Polar |
collection |
HAL Sorbonne Université |
op_collection_id |
ftsorbonneuniv |
language |
English |
topic |
seismotectonics mid-ocean ridges volcano-tectonic interactions focal mechanisms Stress inversion slow spreading ridges Icelandic hot-spot [SDU.STU]Sciences of the Universe [physics]/Earth Sciences |
spellingShingle |
seismotectonics mid-ocean ridges volcano-tectonic interactions focal mechanisms Stress inversion slow spreading ridges Icelandic hot-spot [SDU.STU]Sciences of the Universe [physics]/Earth Sciences Plateaux, Romain Béthoux, Nicole Bergerat, Françoise Mercier de Lépinay, Bernard Volcano-tectonic interactions revealed by inversion of focal mechanisms: stress field insight around and beneath the Vatnajökull ice cape in Iceland |
topic_facet |
seismotectonics mid-ocean ridges volcano-tectonic interactions focal mechanisms Stress inversion slow spreading ridges Icelandic hot-spot [SDU.STU]Sciences of the Universe [physics]/Earth Sciences |
description |
International audience Volcano-tectonic processes in the central part of Iceland, covered by the Vatnajökull glacier, are investigated by inversion of focal mechanisms. Working on a large catalog of focal mechanisms determined by the Icelandic Meteorological Office (IMO), we used a damped regional-scale stress inversion method to obtain an insight of kilometric variations of the stress field. To evaluate the resolution and the stability of this stress field solution, we computed checkerboard tests, stress field models and error propagation tests. Stress field models showed a continuous stress regime between normal and strike-slip faulting, associated with a high stress shape ratio (i.e., σ 1 ≈ σ 2). Two main directions of σ hmin were evidenced: the first one was in agreement with the regional spreading direction of Iceland and the second one was deviated, being almost perpendicular to the first one. The deviated stress direction is sustained through the 20 year time-span of the study around the Bárðarbunga and Grimsvötn central volcanoes while the spreading direction remains predominant around the Hamarinn volcano. This result supports the hypothesis that this volcano lacks collapse caldera and shares a fissure swarm with the larger Bárðarbunga volcano. On a smaller temporal scale, during the 1996 volcanic crisis, a bimodal distribution of σ hmin showed two opposite strike-slip regimes where the deviated direction dominated. Because these two states of stress T1 and T2 show stress regimes away from the Andersonian positions, P, B, and T axes, the rapid flip between these two regimes may be associated with the progressive melt intrusion of a dyke. |
author2 |
Institute of Oceanography Taipei National Taiwan University Taiwan (NTU) Géoazur (GEOAZUR 6526) Institut de Recherche pour le Développement (IRD)-Université Pierre et Marie Curie - Paris 6 (UPMC)-Université Nice Sophia Antipolis (1965 - 2019) (UNS)-Institut national des sciences de l'Univers (INSU - CNRS)-Observatoire de la Côte d'Azur Université Côte d'Azur (UCA)-Université Côte d'Azur (UCA)-Centre National de la Recherche Scientifique (CNRS) Institut des Sciences de la Terre de Paris (iSTeP) Université Pierre et Marie Curie - Paris 6 (UPMC)-Centre National de la Recherche Scientifique (CNRS) |
format |
Article in Journal/Newspaper |
author |
Plateaux, Romain Béthoux, Nicole Bergerat, Françoise Mercier de Lépinay, Bernard |
author_facet |
Plateaux, Romain Béthoux, Nicole Bergerat, Françoise Mercier de Lépinay, Bernard |
author_sort |
Plateaux, Romain |
title |
Volcano-tectonic interactions revealed by inversion of focal mechanisms: stress field insight around and beneath the Vatnajökull ice cape in Iceland |
title_short |
Volcano-tectonic interactions revealed by inversion of focal mechanisms: stress field insight around and beneath the Vatnajökull ice cape in Iceland |
title_full |
Volcano-tectonic interactions revealed by inversion of focal mechanisms: stress field insight around and beneath the Vatnajökull ice cape in Iceland |
title_fullStr |
Volcano-tectonic interactions revealed by inversion of focal mechanisms: stress field insight around and beneath the Vatnajökull ice cape in Iceland |
title_full_unstemmed |
Volcano-tectonic interactions revealed by inversion of focal mechanisms: stress field insight around and beneath the Vatnajökull ice cape in Iceland |
title_sort |
volcano-tectonic interactions revealed by inversion of focal mechanisms: stress field insight around and beneath the vatnajökull ice cape in iceland |
publisher |
HAL CCSD |
publishDate |
2014 |
url |
https://hal.science/hal-01452950 https://hal.science/hal-01452950/document https://hal.science/hal-01452950/file/feart-02-00009.pdf https://doi.org/10.3389/feart.2014.00009 |
long_lat |
ENVELOPE(-17.832,-17.832,64.480,64.480) ENVELOPE(-16.823,-16.823,64.420,64.420) |
geographic |
Hamarinn Vatnajökull |
geographic_facet |
Hamarinn Vatnajökull |
genre |
glacier Iceland Vatnajökull |
genre_facet |
glacier Iceland Vatnajökull |
op_source |
ISSN: 2296-6463 Frontiers in Earth Science https://hal.science/hal-01452950 Frontiers in Earth Science, 2014, 2, pp.9. ⟨10.3389/feart.2014.00009⟩ |
op_relation |
info:eu-repo/semantics/altIdentifier/doi/10.3389/feart.2014.00009 hal-01452950 https://hal.science/hal-01452950 https://hal.science/hal-01452950/document https://hal.science/hal-01452950/file/feart-02-00009.pdf doi:10.3389/feart.2014.00009 |
op_rights |
http://creativecommons.org/licenses/by-nc/ info:eu-repo/semantics/OpenAccess |
op_doi |
https://doi.org/10.3389/feart.2014.00009 |
container_title |
Frontiers in Earth Science |
container_volume |
2 |
_version_ |
1785583535718924288 |