Contribution of active faults in the intraplate area of Iberia to seismic hazard: The Alentejo-Plasencia Fault

We present the earthquake potential characterisation of the Alentejo-Plasencia Fault (APF) in the intraplate area of the Iberian Peninsula. The APF displays clear deformation of geomorphic surfaces and sediments of Neogene and younger age and, thus, we consider it to be active within the current tec...

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Detalles Bibliográficos
Autores: Villamor Pérez, María Pilar, Stirling, M.W., Tsige Beyene, Meaza, Berryman, K.R., Martínez Díaz, José Jesús, Martín-González, F.
Tipo de recurso: artículo
Fecha de publicación:2012
País:España
Institución:Universidad Complutense de Madrid (UCM)
Repositorio:Docta Complutense
Idioma:inglés
OAI Identifier:oai:docta.ucm.es:20.500.14352/43855
Acceso en línea:https://hdl.handle.net/20.500.14352/43855
Access Level:acceso abierto
Palabra clave:551.24(46)
(46)551.24
Alentejo-Plasencia Fault
Active fault
Intraplate Iberia
Hazard assessment
Spain
Falla de Alentejo-Plasencia
Falla activa
Intraplaca ibérica
Peligrosidad sísmica
España.
Geodinámica
2507 Geofísica
Descripción
Sumario:We present the earthquake potential characterisation of the Alentejo-Plasencia Fault (APF) in the intraplate area of the Iberian Peninsula. The APF displays clear deformation of geomorphic surfaces and sediments of Neogene and younger age and, thus, we consider it to be active within the current tectonic regime. APF fault slip rate values range from 0.01 to 0.1 mm/yr with a preferred value of 0.05 mm/yr. Mw associated to fault rupture ranges from 6.6 to 8.7 using different segmentation models (segments ranging from 20 to 500 km) and various fault scaling relationships. Recurrence intervals derived from slip rate and Mw range from 10 ka to 4 Ma, with preferred values between 20 and 30 ka. Other faults in the interior of Iberia present similar values. Hazard curves produced using all fault sources from the intraplate Iberia show that active faults of the intraplate Iberia do not contribute significantly to seismic hazard at short return periods typical of the building codes (~ 500 year return periods). However, they can be important contributors to hazard at critical facilities (high hazard dams, nuclear power plants, emergency response buildings) where return periods of interest may be 10,000 years or more. Our fault source characterisation is very preliminary (with large uncertainties) and further detailed studies of active faults across the whole plate boundary are required to confirm the values for the intraplate faults presented here.