Intermediate depth and deep earthquakes: complexity of the Ibero-Magrhebian region

Detalhes bibliográficos
Autor(a) principal: Buforn, E.
Data de Publicação: 2010
Outros Autores: Cesca, S., Bezzeghoud, M., del Fresno, C., Udias, A.
Tipo de documento: Artigo de conferência
Idioma: por
Título da fonte: Repositório Científico de Acesso Aberto de Portugal (Repositórios Cientìficos)
Texto Completo: http://hdl.handle.net/10174/6488
Resumo: The Ibero-Magrhebian region is located at the plate boundary between Eurasia and Africa and it is a tectonically complex region. A sign of the complexity, is the occurrence of intermediate depth earthquakes (40<h<150 km), located in south Spain, between Granada- Malaga and at the west part of Alboran Sea, together with the occurrence of very deep earthquakes (h≈650 km) near Dúrcal (Granada). Intermediate depth shocks are mostly confined within a relatively narrow region (50 km width) located East of Gibraltar, extending NNE-SSW from the Malaga (Spain) area to a region offshore the Moroccan coast. We have studied focal mechanisms of these earthquakes from inversion of body wave. The stress pattern in the Ibero-Maghrebian region obtained from solutions of selected shallow, intermediate depth and deep shocks show the complexity of the region. The seismotectonic scheme show horizontal compression in NNW-SSE direction in the Gulf of Cádiz. In northern Africa, the stress pattern changes and it corresponds to strike-slip motion, with extends from west of the Gibraltar Strait until the western Algeria, where in the Oran region the horizontal compression N-S reapers, with a clear domain of the thrusting faults in Algeria. In the Alboran Sea there is horizontal extension in E-W direction for shallow events. The intermediate depth shock located at the western part of the Alboran Sea show a change on the stress pattern: to the west of 4.5oW, focal mechanisms show vertical tension axis, while to the east, they show vertical pressure axis. These stress orientations are not present in deep earthquakes, where the pressure axes dip 45o to the east. The intermediate and deep earthquakes may be related to some kind of subduction or delamination processes, more recent for the intermediate depth shocks and older for the very deep activity.
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spelling Intermediate depth and deep earthquakes: complexity of the Ibero-Magrhebian regionIbero-Magrhebian regionIntermediate depth and deep earthquakesFocal MechanismsThe Ibero-Magrhebian region is located at the plate boundary between Eurasia and Africa and it is a tectonically complex region. A sign of the complexity, is the occurrence of intermediate depth earthquakes (40<h<150 km), located in south Spain, between Granada- Malaga and at the west part of Alboran Sea, together with the occurrence of very deep earthquakes (h≈650 km) near Dúrcal (Granada). Intermediate depth shocks are mostly confined within a relatively narrow region (50 km width) located East of Gibraltar, extending NNE-SSW from the Malaga (Spain) area to a region offshore the Moroccan coast. We have studied focal mechanisms of these earthquakes from inversion of body wave. The stress pattern in the Ibero-Maghrebian region obtained from solutions of selected shallow, intermediate depth and deep shocks show the complexity of the region. The seismotectonic scheme show horizontal compression in NNW-SSE direction in the Gulf of Cádiz. In northern Africa, the stress pattern changes and it corresponds to strike-slip motion, with extends from west of the Gibraltar Strait until the western Algeria, where in the Oran region the horizontal compression N-S reapers, with a clear domain of the thrusting faults in Algeria. In the Alboran Sea there is horizontal extension in E-W direction for shallow events. The intermediate depth shock located at the western part of the Alboran Sea show a change on the stress pattern: to the west of 4.5oW, focal mechanisms show vertical tension axis, while to the east, they show vertical pressure axis. These stress orientations are not present in deep earthquakes, where the pressure axes dip 45o to the east. The intermediate and deep earthquakes may be related to some kind of subduction or delamination processes, more recent for the intermediate depth shocks and older for the very deep activity.2012-12-05T21:35:15Z2012-12-052010-05-15T00:00:00Zinfo:eu-repo/semantics/publishedVersioninfo:eu-repo/semantics/conferenceObjecthttp://hdl.handle.net/10174/6488http://hdl.handle.net/10174/6488porBuforn E., Cesca S., M. Bezzeghoud, del Fresno C. and Udías, A., 2010. Intermediate depth and deep earthquakes: complexity of the Ibero-Magrhebian region. International Conference on “Geophysics, Geodesy and Tectonics of the North Africa Plate Boundary for a Better Earthquake and Tsunami Hazard Assessments”. ICTP – International Center for Theoritical Physics (Trieste, Italy), Argel, 15-21 Maio 2010.Algiers (Algeria)1Intermediate depth and deep earthquakes: complexity of the Ibero-Magrhebian regionsimsimnaoCentro de Geofísica de Évora e departamento de Física da Universidade de Évorandndmourad@uevora.ptndnd393Buforn, E.Cesca, S.Bezzeghoud, M.del Fresno, C.Udias, A.info:eu-repo/semantics/openAccessreponame:Repositório Científico de Acesso Aberto de Portugal (Repositórios Cientìficos)instname:Agência para a Sociedade do Conhecimento (UMIC) - FCT - Sociedade da Informaçãoinstacron:RCAAP2024-01-03T18:45:54Zoai:dspace.uevora.pt:10174/6488Portal AgregadorONGhttps://www.rcaap.pt/oai/openaireopendoar:71602024-03-20T01:01:12.542311Repositório Científico de Acesso Aberto de Portugal (Repositórios Cientìficos) - Agência para a Sociedade do Conhecimento (UMIC) - FCT - Sociedade da Informaçãofalse
dc.title.none.fl_str_mv Intermediate depth and deep earthquakes: complexity of the Ibero-Magrhebian region
title Intermediate depth and deep earthquakes: complexity of the Ibero-Magrhebian region
spellingShingle Intermediate depth and deep earthquakes: complexity of the Ibero-Magrhebian region
Buforn, E.
Ibero-Magrhebian region
Intermediate depth and deep earthquakes
Focal Mechanisms
title_short Intermediate depth and deep earthquakes: complexity of the Ibero-Magrhebian region
title_full Intermediate depth and deep earthquakes: complexity of the Ibero-Magrhebian region
title_fullStr Intermediate depth and deep earthquakes: complexity of the Ibero-Magrhebian region
title_full_unstemmed Intermediate depth and deep earthquakes: complexity of the Ibero-Magrhebian region
title_sort Intermediate depth and deep earthquakes: complexity of the Ibero-Magrhebian region
author Buforn, E.
author_facet Buforn, E.
Cesca, S.
Bezzeghoud, M.
del Fresno, C.
Udias, A.
author_role author
author2 Cesca, S.
Bezzeghoud, M.
del Fresno, C.
Udias, A.
author2_role author
author
author
author
dc.contributor.author.fl_str_mv Buforn, E.
Cesca, S.
Bezzeghoud, M.
del Fresno, C.
Udias, A.
dc.subject.por.fl_str_mv Ibero-Magrhebian region
Intermediate depth and deep earthquakes
Focal Mechanisms
topic Ibero-Magrhebian region
Intermediate depth and deep earthquakes
Focal Mechanisms
description The Ibero-Magrhebian region is located at the plate boundary between Eurasia and Africa and it is a tectonically complex region. A sign of the complexity, is the occurrence of intermediate depth earthquakes (40<h<150 km), located in south Spain, between Granada- Malaga and at the west part of Alboran Sea, together with the occurrence of very deep earthquakes (h≈650 km) near Dúrcal (Granada). Intermediate depth shocks are mostly confined within a relatively narrow region (50 km width) located East of Gibraltar, extending NNE-SSW from the Malaga (Spain) area to a region offshore the Moroccan coast. We have studied focal mechanisms of these earthquakes from inversion of body wave. The stress pattern in the Ibero-Maghrebian region obtained from solutions of selected shallow, intermediate depth and deep shocks show the complexity of the region. The seismotectonic scheme show horizontal compression in NNW-SSE direction in the Gulf of Cádiz. In northern Africa, the stress pattern changes and it corresponds to strike-slip motion, with extends from west of the Gibraltar Strait until the western Algeria, where in the Oran region the horizontal compression N-S reapers, with a clear domain of the thrusting faults in Algeria. In the Alboran Sea there is horizontal extension in E-W direction for shallow events. The intermediate depth shock located at the western part of the Alboran Sea show a change on the stress pattern: to the west of 4.5oW, focal mechanisms show vertical tension axis, while to the east, they show vertical pressure axis. These stress orientations are not present in deep earthquakes, where the pressure axes dip 45o to the east. The intermediate and deep earthquakes may be related to some kind of subduction or delamination processes, more recent for the intermediate depth shocks and older for the very deep activity.
publishDate 2010
dc.date.none.fl_str_mv 2010-05-15T00:00:00Z
2012-12-05T21:35:15Z
2012-12-05
dc.type.status.fl_str_mv info:eu-repo/semantics/publishedVersion
dc.type.driver.fl_str_mv info:eu-repo/semantics/conferenceObject
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dc.identifier.uri.fl_str_mv http://hdl.handle.net/10174/6488
http://hdl.handle.net/10174/6488
url http://hdl.handle.net/10174/6488
dc.language.iso.fl_str_mv por
language por
dc.relation.none.fl_str_mv Buforn E., Cesca S., M. Bezzeghoud, del Fresno C. and Udías, A., 2010. Intermediate depth and deep earthquakes: complexity of the Ibero-Magrhebian region. International Conference on “Geophysics, Geodesy and Tectonics of the North Africa Plate Boundary for a Better Earthquake and Tsunami Hazard Assessments”. ICTP – International Center for Theoritical Physics (Trieste, Italy), Argel, 15-21 Maio 2010.
Algiers (Algeria)
1
Intermediate depth and deep earthquakes: complexity of the Ibero-Magrhebian region
sim
sim
nao
Centro de Geofísica de Évora e departamento de Física da Universidade de Évora
nd
nd
mourad@uevora.pt
nd
nd
393
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