DICGF-Artículos
URI permanente para esta colecciónhttps://hdl.handle.net/10953/222
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Examinando DICGF-Artículos por Autor "Avilés-Moreno, Manuel"
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Ítem Active Shortening Simultaneous to Normal Faulting Based on GNSS, Geophysical, and Geological Data: The Seismogenic Ventas de Zafarraya Fault (Betic Cordillera, Southern Spain)(Willey, 2024) Madarieta-Txurruka, Asier; González-Castillo, Lourdes; Peláez, José Antonio; Galindo, Jesús; Borque, María Jesús; de-Lacy, Maria Clara; Ruiz-Armenteros, Antonio Miguel; Henares, Jesús; Ruano, Patricia; Sánchez-Alzola, Alberto; Avilés-Moreno, Manuel; Rodríguez-Caderot, Gracia; Martínez-Moreno, Francisco José; Tendero-Salmerón, Víctor; Vinardell-Peña, Raquel; Gil-Cruz, Antonio JoséThe central Betic Cordillera, southern Spain, is affected by an uplift related to the NNW–SSE Eurasia-Nubia convergence and shallow ENE–WSW orthogonal extension accommodated by the extensional system of the Granada Basin. The combination of geophysical, geodetic, and geological data reveals that the southwestern boundary of this extensional system is a seismically active compressional front extending from the W to the SW of the Granada Basin. The near-field Global Navigation Satellite System data determine NNE–SSW shortening of up to 2 mm/yr of the compressional front in the Zafarraya Polje. In this setting, the normal Ventas de Zafarraya Fault developed as a result of the bending-moment extension of the Sierra de Alhama antiform and was last reactivated during the 1884 Andalusian earthquake (Mw 6.5). The uplift in the central Betic Cordillera together with the subsidence in the Western Alborán Basin may facilitate a westward to southwestward gravitational collapse through the extensional detachment of the Granada Basin. The heterogeneous crust of the Betic Cordillera would generate the compressional front, which is divided into two sectors: thrusting to the west, and folding associated with buttressing to the south. Our results evidence that basal detachments, linking extensional fault activity with compressional fronts, may determine the activity of local surface structures and the geological hazard in densely populated regions.Ítem Displacements Study of an Earth Fill Dam Based on High Precision Geodetic Monitoring and Numerical Modeling(MDPI, 2018-04-27) Acosta, Luis Enrique; de Lacy, Maria Clara; Ramos-Galán, Maria Isabel; Cano, Juan Pedro; Herrera-Olmo, Antonio Manuel; Avilés-Moreno, Manuel; Gil-Cruz, Antonio J.The aim of this paper is to study the behavior of an earth fill dam, analyzing the deformations determined by high precision geodetic techniques and those obtained by the Finite Element Method (FEM). A large number of control points were established around the area of the dam, and the measurements of their displacements took place during several periods. In this study, high-precision leveling and GNSS (Global Navigation Satellite System) techniques were used to monitor vertical and horizontal displacements respectively. Seven surveys were carried out: February and July 2008, March and July 2013, August 2014, September 2015 and September 2016. Deformations were predicted, taking into account the general characteristics of an earth fill dam. A comparative evaluation of the results derived from predicted (FEM) and observed deformations shows the differences on average being 20 cm for vertical displacements, and 6 cm for horizontal displacements at the crest. These differences are probably due to the simplifications assumed during the FEM modeling process: critical sections are considered homogeneous along their longitude, and the properties of the materials were established according to the general characteristics of an earth fill dam. These characteristics were taken from the normative and similar studies in the country. This could also be due to the geodetic control points being anchored in the superficial layer of the slope when the construction of the dam was finished.Ítem High- and Low-Angle Normal Fault Activity in a Collisional Orogen: The Northeastern Granada Basin (Betic Cordillera)(Willey, 2021) Madarieta-Txurruka, Asier; Galindo, Jesús; González-Castillo, Lourdes; Peláez, José Antonio; Ruiz-Armenteros, Antonio Miguel; Henares, Jesús; Garrido-Carretero, María Selmira; Avilés-Moreno, Manuel; Gil-Cruz, Antonio JoséUnderstanding active tectonics and seismicity in extensional settings requires the analysis of high-angle normal faults (HANFs) and the transfer of deformation at depth. The debate surrounds the role of low-angle normal faults (LANFs) in triggering high magnitude earthquakes. The central Betic Cordillera is an active seismic zone affected by the NNW-SSE Eurasia-Nubia convergence and orthogonal extension. The seismicity and present-day stress determined by earthquake focal mechanisms reveals the activity of a NE-SW extensional system in the shallowest 12 km of the Granada Basin. The structure of the sedimentary infill, as derived by geological field and gravimetric techniques, suggests the formation of a half-graben tilted to the N-NE. Seismologic data suggest the activity of HANFs above 6–7 km depth and a LANF zone around 6–12 km depth, with related earthquakes of up to Mw 4.0 and 20° to 30° fault dips. High-precision leveling lines highlight the importance of the Granada Fault in the system, with average vertical displacement rates of 0.35–1.1 mm/yr. These data suggest creep fault behavior at the surface and increased seismicity at depth. The upper crustal extension in the collisional Betic Cordillera is accommodated by a top-to-the-WSW extensional detachment related to westward motion and rollback in the Gibraltar Arc and the gravitational collapse of the cordillera, in a framework of NNW-SSE shortening. This comprehensive study draws a new scenario that advances understanding of relationships between HANFs and LANFs.Ítem How Much Nubia‐Eurasia Convergence Is Accommodated by the NE End of the Eastern Betic Shear Zone (SE Spain)? Constraints From GPS Velocities(American Geophysical Union, 2019-04-29) Borque, María Jesús; Sánchez-Alzola, Alberto; Martín-Rojas, Iván; Alfaro, Pedro; Molina-Palacios, Sergio; Rosa-Cintas, Sergio; Rodríguez-Caderot, Gracia; de-Lacy, María Clara; García-Armenteros, Juan Antonio; Avilés-Moreno, Manuel; Herrera-Olmo, Antonio Manuel; García-Tortosa, Francisco Juan; Estévez-Rubio, Antonio; Gil-Cruz, Antonio JoséWe present the first GPS-derived geodetic observations from the NE end of the Eastern Betic Shear Zone obtained from the Bajo Segura GPS network (SE Spain). The network has 11 GPS sites and was sampled four times between 1999 and 2013. Despite the low signal-to-noise ratio of the residual velocities obtained, the velocities are nonzero at 95% confidence level. We postulate that the GPS data point to the partitioning of deformation into the NNW–SSE shortening and a N70E left-lateral component. The maximum deformation rates are located along the two main active faults in the study area. The maximum shortening rates (north component) in the southern region of the Bajo Segura Basin vary from west to east, ranging from 0.2 to 0.7 mm/year along the Bajo Segura Fault Zone. On the northern border of the basin, along the Crevillente Fault Zone, left-lateral displacement varies between 0.4 and 0.7 mm/year in the E-W direction. The GPS-based regional geodynamic models of the Western Mediterranean indicate that the residual shortening of the Eurasia-Nubia plate convergence is accommodated in the eastern part of the Iberian Peninsula and the Algero-Balearic Basin. Our results indicate that part of this residual deformation occurs at the NE end of the Eastern Betic Shear Zone, but significant deformation must be accommodated also to the north (External Betics) and to the south (Cartagena Basin and offshore area). We postulate that Eurasia-Nubia plate convergence is transferred to the Eastern Betics because of the thin and rigid (potentially oceanic) crust of the Algero-Balearic Basin, which acts as an indenter.Ítem The Campo de Dalias GNSS Network Unveils the Interaction between Roll-Back and Indentation Tectonics in the Gibraltar Arc(MDPI, 2022-03-09) Galindo, Jesús; Gil-Cruz, Antonio José; Tendero-Salmerón, Víctor; Borque, María Jesús; Ercilla, Gemma; González-Castillo, Lourdes; Sánchez-Alzola, Alberto; de-Lacy, María Clara ; Estrada, Ferran; Avilés-Moreno, Manuel; Alfaro, Pedro; Madarieta-Txurruka, Asier; Chacón, FernandoThe Gibraltar Arc includes the Betic and Rif Cordilleras surrounding the Alboran Sea; it is formed at the northwest-southeast Eurasia–Nubia convergent plate boundary in the westernmost Mediterranean. Since 2006, the Campo de Dalias GNSS network has monitored active tectonic deformation of the most seismically active area on the north coast of the Alboran Sea. Our results show that the residual deformation rates with respect to Eurasia range from 1.7 to 3.0 mm/year; roughly homogenous west-southwestward displacements of the northern sites occur, while the southern sites evidence irregular displacements towards the west and northwest. This deformation pattern supports simultaneous east-northeast–west-southwest extension, accommodated by normal and oblique faults, and north-northwest-south-southeast shortening that develops east-northeast–west-southwest folds. Moreover, the GNSS results point to dextral creep of the main northwest–southeast Balanegra Fault. These GNNS results thus reveal, for the first time, the present-day interaction of the roll-back tectonics of the Rif–Gibraltar–Betic slab in the western part of the Gibraltar Arc with the indentation tectonics affecting the eastern and southern areas, providing new insights for improving tectonic models of arcuate orogens.