Geological evidences of surface rupture related to a seventeenth century destructive earthquake in Betic Cordillera, SE Spainconstraining the seismic hazard of the Alhama de Murcia fault
- José J. Martínez-Díaz 1
- Jorge Alonso-Henar 1
- Juan M. Insua-Arévalo 1
- Carolina Canora 2
- Julian García-Mayordomo 3
- Emilio Rodríguez-Escudero 2
- José A. Álvarez-Gómez 1
- Marta Ferrater 4
- María Ortuño 4
- Eulalia Masana 4
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1
Universidad Complutense de Madrid
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2
Universidad Autónoma de Madrid
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3
Instituto Geológico y Minero de España
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4
Universitat de Barcelona
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ISSN: 1886-7995, 1698-6180
Year of publication: 2019
Volume: 45
Issue: 1
Pages: 73-86
Type: Article
More publications in: Journal of iberian geology: an international publication of earth sciences
Abstract
Constraining the date of the last major event occurred in a fault is of paramount importance in probabilistic seismic hazard assessment when time-dependent models are considered. Eight of the twelve destructive earthquakes occurred in the eastern Betic Cordillera since sixteenth century, are located less than 10 km away from the Alhama de Murcia fault (AMF). Up to now, it has not been identifed any geological evidence on the ground surface to associate these events with the activity of specifc fault sections of the AMF. In this work we present the frst geological evidence of the catastrophic 1674 event occurred at Lorca (SE Spain). The excavations carried out at La Torrecilla Creek exposed archaeological remains from the Islamic period (VIII–XIII centuries in this region) afected by 55±20 cm ofset by the AMF fault. This event reached intensity VIII and produced 30 fatalities at Lorca for an estimated population of 7300 inhabitants. This supports the occurrence of earthquakes with surface rupture in the historical epoch on the Alhama de Murcia fault and reinforces the results obtained in previous paleoseismological work. The theoretical scenarios of maximum magnitudes and recurrence time obtained by combining this historical event with the fault slip rate allow us to conclude that the seismic hazard associated with maximum magnitude events in this section could be high. In addition, the static Coulomb stress transferred to the Góñar–Lorca section by the 2011 (Mw 5.2) Lorca earthquake may have signifcantly increased the hazard.
Funding information
Funders
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Secretaría de Estado de Investigación, Desarrollo e Innovación
- CGL2013-47412-C2-1-P