Medidas de deformaciones co-sismicas del terremoto de Lorca de 11 de mayo de 2011

Abstract

ResumenLa deformación cosísmica superficial en la región de Lorca debida al terremoto de M w 5.1 ocurrido el día 11 de mayo de 2011 ha sido caracterizada por un equipo multidisciplinario que ha integrado técnicas de interferometría DInSAR (Synthetic Aperture Radar Differential Interferometry) y modelación numérica. A pesar de la magnitud moderada del terremoto, se ha obtenido información cuantitativa mediante un estudio interferométrico de un par de imágenes TerraSAR-X. Los resultados DInSAR definen la traza del plano de falla y ponen en evidencia el levantamiento de algunos centímetros del bloque superior, en concordancia con la deformación estimada obtenida mediante un modelo numérico de ruptura en un medio elástico. Además, para el bloque inferior, los resultados interferométricos muestran que la deformación tectónica queda enmascarada por un movimiento de subsidencia relacionado con la extracción de agua del subsuelo, previamente identificada en la zona de estudio. Palabras clave: Deformación cosísmica, DInSAR, Modelo numérico de dislocación. DInSAR Coseismic Deformations Measurements of the 11 May 2011 Lorca Earthquake AbstractThe coseismic superficial deformation at the region of Lorca (Murcia, south-eastern Spain) due to the M w 5.1 earthquake, on 11 May 2011, was characterized by a multidisciplinary team, integrating information from DInSAR (Synthetic Aperture Radar Differential Interferometry) and numerical modelling techniques. Despite the moderate magnitude of the event, quantitative information was obtained from the interferometric study of a pair of TerraSAR-X images. The DInSAR results defined the trace of the fault plane and evidenced uplift of some centimetres of the hanging wall block in agreement with the estimated deformation obtained through an elastic rupture dislocation numerical model. Meanwhile, for the footwall block, interferometric results showed that tectonic deformation is masked by an important subsidence related to groundwater extraction previously identified at the area of study.

Analysis of faulted fan surfaces and paleosols in the Palomares Fault Zone (Betic Cordillera, SE Spain): Paleoclimatic and paleoseismic implications

“…The EBSZ, focus of the main historical and instrumental seismicity in the Eastern Betic Cordillera, whose most recent relevant event is the well-known 2011 Lorca Earthquake (5.1 Mw; VII EMS), comes from activity of the central segment of the LAF (Martínez Díaz et al, 2012). This earthquake, produced by a reverse strike-slip displacement of 0.19 m at 2 km depth, resulting in a regional flexure (c. 2 km wide) of the ground surface of 9 ± 3 mm, determined by GPS and Dinsar analyses (Frontera et al, 2012). This event, the last instrumental earthquake recorded in the zone, was a non-surfacefaulting event.…”