Estimation of slip rates and seismic hazard parameters using conventional techniques of structural geology in a slow-moving fault: Alhama de Murcia – Alcantarilla segment of the Alhama de Murcia Fault (Murcia, SE Spain)

The convergence between Nubian and Eurasian plates in the Western Mediterranean is being accommodated by the Eastern Betic Shear Zone, located in Southeastern Iberia. This is a low strain region whose faults show low slip rates and long recurrence periods of their maximum earthquakes, so they do not...

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Autores: Herrero-Barbero, Paula, Álvarez Gómez, José Antonio, Martínez Díaz, José Jesús
Tipo de recurso: artículo
Fecha de publicación:2017
País:España
Institución:Universidad Complutense de Madrid (UCM)
Repositorio:Docta Complutense
Idioma:español
OAI Identifier:oai:docta.ucm.es:20.500.14352/18611
Acceso en línea:https://hdl.handle.net/20.500.14352/18611
Access Level:acceso abierto
Palabra clave:551.2/.3
Geoquímica
2503 Geoquímica
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spelling Estimation of slip rates and seismic hazard parameters using conventional techniques of structural geology in a slow-moving fault: Alhama de Murcia – Alcantarilla segment of the Alhama de Murcia Fault (Murcia, SE Spain)Herrero-Barbero, PaulaÁlvarez Gómez, José AntonioMartínez Díaz, José Jesús551.2/.3Geoquímica2503 GeoquímicaThe convergence between Nubian and Eurasian plates in the Western Mediterranean is being accommodated by the Eastern Betic Shear Zone, located in Southeastern Iberia. This is a low strain region whose faults show low slip rates and long recurrence periods of their maximum earthquakes, so they do not provide clear evidence of their seismogenic activity. The Alhama de Murcia - Alcantarilla segment, defined as the NE end of the Alhama de Murcia Fault, is one of the structures of the Eastern Betic Shear Zone and there are few in-depth studies about its seismic potential. In order to assess the seismogenic potential and slip-rate of this segment we have carried out a structural analysis. We have built a 3D geological model of the area where the fault is currently bounding the Neogene Fortuna basin. The structural model is based on seismic reflection profiles which have been later input in MOVE, structural modelling and analysis software. The analysis of the model has revealed several structural features related to positive inversion tectonics in Fortuna basin, specifically a typical "harpoon" structure whose deformation is estimated to have begun since Upper Miocene (Messinian). Geometric models and area balance methods (e.g. depth-to-detachment method) applied to the previously mentioned structure have allowed to estimate the heave of the fault, representing the amount of shortening observed in the fault section during its recent activity. The horizontal shortening rate estimated is between 0.09 and 0.26 mm/yr during the last 5.3 - 2.6 Ma. Projecting the obtained shortening onto the fault plane and considering the present regional tectonic shortening it has been possible to obtain a net slip rate between 0.13 and 0.37 mm/yr. Such parameters suggest that the Alhama de Murcia - Alcantarilla segment has less activity than other segments of the fault. The result obtained is consistent with the fact that the Carrascoy Fault, oriented parallel and located to the south of the Alhama de Murcia - Alcantarilla segment, seems to absorb part of the regional tectonic shortening. That is why the relief uplifted by the Alhama de Murcia - Alcantarilla segment during the Quaternary is significantly less prominent than the mountains fronts generated by the Carrascoy Fault. Even so, Alhama de Murcia - Alcantarilla segment should be considered as an active structure with implications for seismic hazard. The maximum size of earthquake is calculated to be Mw 6.3 - 6.6 according to magnitude-area and magnitude-length scaling relationships, with a mean recurrence interval lower than 10.000 years for the slip rate obtained. In the same way, Mw 5.0 earthquakes, such as those recorded in the historical seismic catalog, are estimated to have a recurrence interval lower than 50 years. These earthquakes could be very destructive in densely populated areas, as is the case of SE Spain, so they should be considered in seismic-hazard analysis.EGU General AssemblyUniversidad Complutense de Madrid20172017-01-0120172017-01-01journal articlehttp://purl.org/coar/resource_type/c_6501info:eu-repo/semantics/articleapplication/pdfhttps://hdl.handle.net/20.500.14352/18611reponame:Docta Complutenseinstname:Universidad Complutense de Madrid (UCM)Españolspaopen accesshttp://purl.org/coar/access_right/c_abf2Atribución 3.0 Españahttps://creativecommons.org/licenses/by/3.0/es/info:eu-repo/semantics/openAccessoai:docta.ucm.es:20.500.14352/186112026-06-02T12:44:21Z
dc.title.none.fl_str_mv Estimation of slip rates and seismic hazard parameters using conventional techniques of structural geology in a slow-moving fault: Alhama de Murcia – Alcantarilla segment of the Alhama de Murcia Fault (Murcia, SE Spain)
title Estimation of slip rates and seismic hazard parameters using conventional techniques of structural geology in a slow-moving fault: Alhama de Murcia – Alcantarilla segment of the Alhama de Murcia Fault (Murcia, SE Spain)
spellingShingle Estimation of slip rates and seismic hazard parameters using conventional techniques of structural geology in a slow-moving fault: Alhama de Murcia – Alcantarilla segment of the Alhama de Murcia Fault (Murcia, SE Spain)
Herrero-Barbero, Paula
551.2/.3
Geoquímica
2503 Geoquímica
title_short Estimation of slip rates and seismic hazard parameters using conventional techniques of structural geology in a slow-moving fault: Alhama de Murcia – Alcantarilla segment of the Alhama de Murcia Fault (Murcia, SE Spain)
title_full Estimation of slip rates and seismic hazard parameters using conventional techniques of structural geology in a slow-moving fault: Alhama de Murcia – Alcantarilla segment of the Alhama de Murcia Fault (Murcia, SE Spain)
title_fullStr Estimation of slip rates and seismic hazard parameters using conventional techniques of structural geology in a slow-moving fault: Alhama de Murcia – Alcantarilla segment of the Alhama de Murcia Fault (Murcia, SE Spain)
title_full_unstemmed Estimation of slip rates and seismic hazard parameters using conventional techniques of structural geology in a slow-moving fault: Alhama de Murcia – Alcantarilla segment of the Alhama de Murcia Fault (Murcia, SE Spain)
title_sort Estimation of slip rates and seismic hazard parameters using conventional techniques of structural geology in a slow-moving fault: Alhama de Murcia – Alcantarilla segment of the Alhama de Murcia Fault (Murcia, SE Spain)
dc.creator.none.fl_str_mv Herrero-Barbero, Paula
Álvarez Gómez, José Antonio
Martínez Díaz, José Jesús
author Herrero-Barbero, Paula
author_facet Herrero-Barbero, Paula
Álvarez Gómez, José Antonio
Martínez Díaz, José Jesús
author_role author
author2 Álvarez Gómez, José Antonio
Martínez Díaz, José Jesús
author2_role author
author
dc.contributor.none.fl_str_mv Universidad Complutense de Madrid
dc.subject.none.fl_str_mv 551.2/.3
Geoquímica
2503 Geoquímica
topic 551.2/.3
Geoquímica
2503 Geoquímica
description The convergence between Nubian and Eurasian plates in the Western Mediterranean is being accommodated by the Eastern Betic Shear Zone, located in Southeastern Iberia. This is a low strain region whose faults show low slip rates and long recurrence periods of their maximum earthquakes, so they do not provide clear evidence of their seismogenic activity. The Alhama de Murcia - Alcantarilla segment, defined as the NE end of the Alhama de Murcia Fault, is one of the structures of the Eastern Betic Shear Zone and there are few in-depth studies about its seismic potential. In order to assess the seismogenic potential and slip-rate of this segment we have carried out a structural analysis. We have built a 3D geological model of the area where the fault is currently bounding the Neogene Fortuna basin. The structural model is based on seismic reflection profiles which have been later input in MOVE, structural modelling and analysis software. The analysis of the model has revealed several structural features related to positive inversion tectonics in Fortuna basin, specifically a typical "harpoon" structure whose deformation is estimated to have begun since Upper Miocene (Messinian). Geometric models and area balance methods (e.g. depth-to-detachment method) applied to the previously mentioned structure have allowed to estimate the heave of the fault, representing the amount of shortening observed in the fault section during its recent activity. The horizontal shortening rate estimated is between 0.09 and 0.26 mm/yr during the last 5.3 - 2.6 Ma. Projecting the obtained shortening onto the fault plane and considering the present regional tectonic shortening it has been possible to obtain a net slip rate between 0.13 and 0.37 mm/yr. Such parameters suggest that the Alhama de Murcia - Alcantarilla segment has less activity than other segments of the fault. The result obtained is consistent with the fact that the Carrascoy Fault, oriented parallel and located to the south of the Alhama de Murcia - Alcantarilla segment, seems to absorb part of the regional tectonic shortening. That is why the relief uplifted by the Alhama de Murcia - Alcantarilla segment during the Quaternary is significantly less prominent than the mountains fronts generated by the Carrascoy Fault. Even so, Alhama de Murcia - Alcantarilla segment should be considered as an active structure with implications for seismic hazard. The maximum size of earthquake is calculated to be Mw 6.3 - 6.6 according to magnitude-area and magnitude-length scaling relationships, with a mean recurrence interval lower than 10.000 years for the slip rate obtained. In the same way, Mw 5.0 earthquakes, such as those recorded in the historical seismic catalog, are estimated to have a recurrence interval lower than 50 years. These earthquakes could be very destructive in densely populated areas, as is the case of SE Spain, so they should be considered in seismic-hazard analysis.
publishDate 2017
dc.date.none.fl_str_mv 2017
2017-01-01
2017
2017-01-01
dc.type.none.fl_str_mv journal article
http://purl.org/coar/resource_type/c_6501
dc.type.openaire.fl_str_mv info:eu-repo/semantics/article
format article
dc.identifier.none.fl_str_mv https://hdl.handle.net/20.500.14352/18611
url https://hdl.handle.net/20.500.14352/18611
dc.language.none.fl_str_mv Español
spa
language_invalid_str_mv Español
language spa
dc.rights.none.fl_str_mv open access
http://purl.org/coar/access_right/c_abf2
Atribución 3.0 España
https://creativecommons.org/licenses/by/3.0/es/
dc.rights.openaire.fl_str_mv info:eu-repo/semantics/openAccess
rights_invalid_str_mv open access
http://purl.org/coar/access_right/c_abf2
Atribución 3.0 España
https://creativecommons.org/licenses/by/3.0/es/
eu_rights_str_mv openAccess
dc.format.none.fl_str_mv application/pdf
dc.publisher.none.fl_str_mv EGU General Assembly
publisher.none.fl_str_mv EGU General Assembly
dc.source.none.fl_str_mv reponame:Docta Complutense
instname:Universidad Complutense de Madrid (UCM)
instname_str Universidad Complutense de Madrid (UCM)
reponame_str Docta Complutense
collection Docta Complutense
repository.name.fl_str_mv
repository.mail.fl_str_mv
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