Ambient noise tomography of the Pyrenees and the surrounding regions: Inversion for a 3-D Vs model in the presence of a very heterogeneous crust

The lithospheric architecture of the Pyrenees is still uncertain and highly debated. Here, we provide new constraints from a high-resolution 3-D S-wave velocity model of the Pyrenees and the adjacent foreland basins. This model is obtained from ambient noise tomography on records of temporary and pe...

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Autores: Macquet, M, Paul, A., Pedersen, H.A., Villaseñor, Antonio, Chevrot, Sébastien, Sylvander, Matthieu, Wolyniec, D.
Tipo de recurso: artículo
Estado:Versión publicada
Fecha de publicación:2014
País:España
Institución:Consejo Superior de Investigaciones Científicas (CSIC)
Repositorio:DIGITAL.CSIC. Repositorio Institucional del CSIC
OAI Identifier:oai:digital.csic.es:10261/102229
Acceso en línea:http://hdl.handle.net/10261/102229
Access Level:acceso abierto
Palabra clave:Crustal structure
Europe
Seismic tomography
Surface waves and free oscillations
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network_name_str España
repository_id_str
dc.title.none.fl_str_mv Ambient noise tomography of the Pyrenees and the surrounding regions: Inversion for a 3-D Vs model in the presence of a very heterogeneous crust
title Ambient noise tomography of the Pyrenees and the surrounding regions: Inversion for a 3-D Vs model in the presence of a very heterogeneous crust
spellingShingle Ambient noise tomography of the Pyrenees and the surrounding regions: Inversion for a 3-D Vs model in the presence of a very heterogeneous crust
Macquet, M
Crustal structure
Europe
Seismic tomography
Surface waves and free oscillations
title_short Ambient noise tomography of the Pyrenees and the surrounding regions: Inversion for a 3-D Vs model in the presence of a very heterogeneous crust
title_full Ambient noise tomography of the Pyrenees and the surrounding regions: Inversion for a 3-D Vs model in the presence of a very heterogeneous crust
title_fullStr Ambient noise tomography of the Pyrenees and the surrounding regions: Inversion for a 3-D Vs model in the presence of a very heterogeneous crust
title_full_unstemmed Ambient noise tomography of the Pyrenees and the surrounding regions: Inversion for a 3-D Vs model in the presence of a very heterogeneous crust
title_sort Ambient noise tomography of the Pyrenees and the surrounding regions: Inversion for a 3-D Vs model in the presence of a very heterogeneous crust
dc.creator.none.fl_str_mv Macquet, M
Paul, A.
Pedersen, H.A.
Villaseñor, Antonio
Chevrot, Sébastien
Sylvander, Matthieu
Wolyniec, D.
author Macquet, M
author_facet Macquet, M
Paul, A.
Pedersen, H.A.
Villaseñor, Antonio
Chevrot, Sébastien
Sylvander, Matthieu
Wolyniec, D.
author_role author
author2 Paul, A.
Pedersen, H.A.
Villaseñor, Antonio
Chevrot, Sébastien
Sylvander, Matthieu
Wolyniec, D.
author2_role author
author
author
author
author
author
dc.contributor.none.fl_str_mv Consejo Superior de Investigaciones Científicas [https://ror.org/02gfc7t72]
dc.subject.none.fl_str_mv Crustal structure
Europe
Seismic tomography
Surface waves and free oscillations
topic Crustal structure
Europe
Seismic tomography
Surface waves and free oscillations
description The lithospheric architecture of the Pyrenees is still uncertain and highly debated. Here, we provide new constraints from a high-resolution 3-D S-wave velocity model of the Pyrenees and the adjacent foreland basins. This model is obtained from ambient noise tomography on records of temporary and permanent seismic arrays installed in southwestern France and northern Spain. We first computed group velocity maps for Rayleigh waves in the 5 to 55 s period range using noise correlation stacks at 1500-8500 station pairs. As the crust is very heterogeneous, poor results were obtained using a single starting model in a linearized inversion of group velocity dispersion curves for the shear wave structure. We therefore built a starting model for each grid node by full exploration of the model space. The resulting 3-D shear wave velocity model is compared to data from previous geophysical studies as a validation test. Despite the poor sensitivity of surface waves to seismic discontinuities, the geometry of the top of the basement and the Moho depth are retrieved well, except along the Cantabrian coast. Major reflectors of the ECORS deep seismic sounding profiles in the central and western Pyrenees coincide with sharp velocity gradients in our velocity model.We retrieve the difference between the thicker Iberian crust and the thinner European crust, the presence of low-velocity material of the Iberian crust underthrust beneath the European crust in the central Pyrenees, and the structural dissymmetry between the South Pyrenean Zone and the North Pyrenean Zone at the shallow crustal level. In the Labourd-Mauléon-Arzacq region (western Pyrenees), there is a high S-wave velocity anomaly at 20-30 km in depth, which might explain the positive Bouguer anomaly of the Labourd Massif. This high-velocity lower crust, which is also detected beneath the Parentis area, might be an imprint of the Albian-Aptian rifting phase. The southeastern part of the Massif Central has an unusual velocity structure, with a very shallowMoho (21-25 km) above an uppermost mantle with anomalously low shear wave velocity.
publishDate 2014
dc.date.none.fl_str_mv 2014
2014
2014
dc.type.none.fl_str_mv info:eu-repo/semantics/article
http://purl.org/coar/resource_type/c_6501
Publisher's version
info:eu-repo/semantics/publishedVersion
format article
status_str publishedVersion
dc.identifier.none.fl_str_mv http://hdl.handle.net/10261/102229
url http://hdl.handle.net/10261/102229
dc.language.none.fl_str_mv Inglés
language_invalid_str_mv Inglés
dc.relation.none.fl_str_mv http://dx.doi.org/10.1093/gji/ggu270
Sí
dc.rights.none.fl_str_mv info:eu-repo/semantics/openAccess
eu_rights_str_mv openAccess
dc.publisher.none.fl_str_mv Oxford University Press
publisher.none.fl_str_mv Oxford University Press
dc.source.none.fl_str_mv reponame:DIGITAL.CSIC. Repositorio Institucional del CSIC
instname:Consejo Superior de Investigaciones Científicas (CSIC)
instname_str Consejo Superior de Investigaciones Científicas (CSIC)
reponame_str DIGITAL.CSIC. Repositorio Institucional del CSIC
collection DIGITAL.CSIC. Repositorio Institucional del CSIC
repository.name.fl_str_mv
repository.mail.fl_str_mv
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spelling Ambient noise tomography of the Pyrenees and the surrounding regions: Inversion for a 3-D Vs model in the presence of a very heterogeneous crustMacquet, MPaul, A.Pedersen, H.A.Villaseñor, AntonioChevrot, SébastienSylvander, MatthieuWolyniec, D.Crustal structureEuropeSeismic tomographySurface waves and free oscillationsThe lithospheric architecture of the Pyrenees is still uncertain and highly debated. Here, we provide new constraints from a high-resolution 3-D S-wave velocity model of the Pyrenees and the adjacent foreland basins. This model is obtained from ambient noise tomography on records of temporary and permanent seismic arrays installed in southwestern France and northern Spain. We first computed group velocity maps for Rayleigh waves in the 5 to 55 s period range using noise correlation stacks at 1500-8500 station pairs. As the crust is very heterogeneous, poor results were obtained using a single starting model in a linearized inversion of group velocity dispersion curves for the shear wave structure. We therefore built a starting model for each grid node by full exploration of the model space. The resulting 3-D shear wave velocity model is compared to data from previous geophysical studies as a validation test. Despite the poor sensitivity of surface waves to seismic discontinuities, the geometry of the top of the basement and the Moho depth are retrieved well, except along the Cantabrian coast. Major reflectors of the ECORS deep seismic sounding profiles in the central and western Pyrenees coincide with sharp velocity gradients in our velocity model.We retrieve the difference between the thicker Iberian crust and the thinner European crust, the presence of low-velocity material of the Iberian crust underthrust beneath the European crust in the central Pyrenees, and the structural dissymmetry between the South Pyrenean Zone and the North Pyrenean Zone at the shallow crustal level. In the Labourd-Mauléon-Arzacq region (western Pyrenees), there is a high S-wave velocity anomaly at 20-30 km in depth, which might explain the positive Bouguer anomaly of the Labourd Massif. This high-velocity lower crust, which is also detected beneath the Parentis area, might be an imprint of the Albian-Aptian rifting phase. The southeastern part of the Massif Central has an unusual velocity structure, with a very shallowMoho (21-25 km) above an uppermost mantle with anomalously low shear wave velocity.We thank all participants in the fieldwork, and the municipalities and landlords that hosted a PYROPE temporary station. We also acknowledge SISMOB, the French seismic mobile pool (a com- ponent of the RESIF Research Facility), for providing us with the seismological instrumentation for the temporary deployments. We used data from the FR and RD (RESIF), G (Geoscope) and CA (‘Institut Cartogr ` afic i Geol ` ogic de Catalunya’) permanent net- works. RESIF ( http://portal.resif.fr/ ) is a national Research Infras- tructure, recognized as such by the French Ministry of Higher Education and Research. RESIF is managed by the RESIF Con- sortium, composed of 18 Research Institutions and Universities in France. RESIF additionally supported by a public grant overseen by the French National Research Agency (ANR) as part of the «Investissements d’Avenir» program (reference: ANR-11-EQPX- 0040)andtheFrenchMinistryofEcology,SustainableDevelopment and Energy. The PYROPE experiment was supported by the French Research Agency “ANR blanc” program (project PYROPE, ANR-09-BLAN-0229). This is a contribution of the Team Consolider-Ingenio 2010 TOPO-IBERIA (CSD2006–00041). CPeer reviewedOxford University PressConsejo Superior de Investigaciones Científicas [https://ror.org/02gfc7t72]201420142014info:eu-repo/semantics/articlehttp://purl.org/coar/resource_type/c_6501Publisher's versioninfo:eu-repo/semantics/publishedVersionhttp://hdl.handle.net/10261/102229reponame:DIGITAL.CSIC. Repositorio Institucional del CSICinstname:Consejo Superior de Investigaciones Científicas (CSIC)Ingléshttp://dx.doi.org/10.1093/gji/ggu270Síinfo:eu-repo/semantics/openAccessoai:digital.csic.es:10261/1022292026-05-22T06:33:51Z
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