Modelización 3D de la estructura, la cinemática y el comportamiento sismogénico del sistema de fallas de las Béticas Orientalesaplicación a la amenaza sísmica

Résumé

Characterizing the relationship between the occurrence of earthquakes and the threedimensional geometry, kinematics and deformation rates of the faults of an active region is essential for the seismic hazard assessment. In areas with slow deformation, the study of active faults is complex due to the scarce evidence of recent tectonic activity, often vague or covered by intense surface processes, and a limited and inaccurate historical seismic record. The Eastern Betic Fault System (also known as the Eastern Betic Shear Zone), is located southeast of the Iberian Peninsula and belongs to the Trans-Alboran Shear Zone. It is a good example of an active system formed by faults with low deformation rates (mostly, less than 1 mm/yr). The lack of slip-rates and other kinematic data in some of their fault sections, as well as their moderate to low seismicity, have often led to an underestimation of the seismogenic potential of these faults to generate major earthquakes. The MW 5.1 Lorca earthquake that occurred in May 2011, associated with this fault system and causing fatalities and significant material damage, revealed the urgent need to going into detail about the seismogenic behavior of these faults. This dissertation addresses the study of the Eastern Betic Fault System at different scales, focusing on its 3D structure, the estimation of deformation rates and the fault interactions, and evaluating how the latter influence the spatio-temporal distribution of long-term seismicity.