Enhanced paleoseismic succession at the Concud Fault (Iberian Chain, Spain): new insights for seismic hazard assessment

A new trench excavated at the southern sector of the Concud Fault provided evidence of three palaeoseismic events dated to ca. 21, 18 and 13–3 ka BP, respectively. The two youngest ones had not been detected in previous studies. The results extend the total recorded palaeoseismic succession for the...

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Detalles Bibliográficos
Autores: Simón, José L., Arlegui, Luis E., Ezquerro Ruiz, Lope, Lafuente, Paloma, Liesa, Carlos L., Luzón, Mª Aránzazu
Tipo de recurso: artículo
Fecha de publicación:2015
País:España
Institución:Universidad Complutense de Madrid (UCM)
Repositorio:Docta Complutense
Idioma:inglés
OAI Identifier:oai:docta.ucm.es:20.500.14352/114484
Acceso en línea:https://hdl.handle.net/20.500.14352/114484
Access Level:acceso abierto
Palabra clave:551(460)
Concud fault
Iberian chain
Active tectonics
Palaeoseismology
Seismic hazard
Intraplate seismicity
Geología
25 Ciencias de la Tierra y del Espacio
2506 Geología
Descripción
Sumario:A new trench excavated at the southern sector of the Concud Fault provided evidence of three palaeoseismic events dated to ca. 21, 18 and 13–3 ka BP, respectively. The two youngest ones had not been detected in previous studies. The results extend the total recorded palaeoseismic succession for the fault: eleven events since ca. 74 ka BP to the present day, with an average recurrence period between 7.1 ± 3.5 and 8.0 ± 3.3 ka; total net accumulated slip of about 20.5 m, with average coseismic slip of 1.9 m. The displacement pattern shows alternating periods of fast slip (up to 0.53 mm/a) and slow slip (0.13 mm/a), resulting in average slip rate of 0.29 mm/a. Using this palaeoseismic information, as well as the potential magnitude previously attributed to the characteristic earthquake at the Concud Fault (M ≈ 6.5–6.6), a simple probabilistic seismic hazard analysis has been performed. The estimated probability of occurrence of the characteristic earthquake within the next 500-year period ranges from 2.3 to 26.1 %, according to distinct hypotheses on the elapsed time derived from the uncertainty about the age of the youngest event.