Quaternary active tectonic structures in the offshore Bajo Segura basin (SE Iberian Peninsula – Mediterranean Sea)

Autor: Eulàlia Gràcia, Rafael Bartolomé, C. Lo Iacono, Event-Shelf Team, Ximena Moreno, Héctor Perea, Pedro Alfaro, Eulàlia Masana
Přispěvatelé: Universitat de Barcelona
Jazyk: angličtina
Rok vydání: 2018
Předmět:
Zdroj: Natural Hazards and Earth System Sciences, Vol 12, Iss 10, Pp 3151-3168 (2012)
Digital.CSIC. Repositorio Institucional del CSIC
instname
Natural Hazards and Earth System Sciences, 12 (10). pp. 3151-3168.
Dipòsit Digital de la UB
Universidad de Barcelona
Recercat. Dipósit de la Recerca de Catalunya
ISSN: 1684-9981
Popis: Perea, Héctor ... et. al.-- EVENT SHELF team is formed by Marcel-lí Farran, E. Andara, S. Pérez and M. Román Alpiste. -- 18 pages, 10 figures
The Bajo Segura fault zone (BSFZ) is the northern terminal splay of the Eastern Betic shear zone (EBSZ), a large left-lateral strike-slip fault system of sigmoid geometry stretching more than 450 km from Alicante to Almería. The BSFZ extends from the onshore Bajo Segura basin further into the Mediterranean Sea and shows a moderate instrumental seismic activity characterized by small earthquakes. Nevertheless, the zone was affected by large historical earthquakes of which the largest was the 1829 Torrevieja earthquake (IEMS98 X). The onshore area of the BSFZ is marked by active transpressive structures (faults and folds), whereas the offshore area has been scarcely explored from the tectonic point of view. During the EVENT-SHELF cruise, a total of 10 high-resolution single-channel seismic sparker profiles were obtained along and across the offshore Bajo Segura basin. Analysis of these profiles resulted in (a) the identification of 6 Quaternary seismo-stratigraphic units bounded by five horizons corresponding to regional erosional surfaces related to global sea level lowstands; and (b) the mapping of the active sub-seafloor structures and their correlation with those described onshore. Moreover, the results suggest that the Bajo Segura blind thrust fault or the Torrevieja left-lateral strike-slip fault, with prolongation offshore, could be considered as the source of the 1829 Torrevieja earthquake. These data improve our understanding of present deformation along the BSFZ and provide new insights into the seismic hazard in the area
The authors acknowledge the support of the Spanish Ministry of Science and Innovation through National Projects IMPULS (REN2003-05996MAR), EVENT (CGL 2006-12861-C02-02) and SHAKE (CGL 2011-30005-C02-02); Acciones Complementarias EVENT-SHELF (CTM 2008-03346-E/MAR) and SPARKER (CTM 2008-03208-E/MAR); and ESF TopoEurope TOPOMED project (CGL 2008-03474-E/BTE). We are grateful to the captain, crew and science party onboard the RV Garcia del Cid. Hector Perea was a researcher at IDL-UL Associated Laboratory under contract no. 3/2010/LAB IDL co-financed by the Portuguese FCT and FEDER and at UTM-CSIC under the Juan de la Cierva contract no. JCI-2010-07502 funded by the Spanish Ministry of Science and Innovation
Databáze: OpenAIRE
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