Examinando por Autor "de-Lacy, Maria Clara"
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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 Is GNSS real-time positioning a reliable option to validate erosion studies at olive grove environments?(CSIC, 2020-09-22) Garrido-Carretero, María Selmira; Ramos-Galán, María Isabel; de-Lacy, Maria Clara; Blanca-Mena, Sergio; Gil-Cruz, Antonio JoséAim of study: Soil degradation in agricultural areas is a widespread problem. In this framework, a data validation methodology is pre-sented, including a study of the spatial resolution of Global Navigation Satellite System (GNSS) measurements, the calculation of erosion/deposition models, and the contribution of dual frequency and low-cost single frequency GNSS receivers. Area of study: A test olive grove in SE Spain.Material and methods: The study is based on three observation campaigns, between 2016 and 2018, using different GNSS receivers and working modes. The comparison between different surveys provide the volumetric variation over the analyzed period. Main results: Considering the dual-frequency receiver, there was no statistically significant difference between the means and the va-riances from 1.5 m and from 4.5 m data resolution at the 0.05 significance level. In order to estimate vertical differences from successive GNSS campaigns a differential digital elevation approach was applied. Although the differences depended on the zone of the test area and they changed along the monitoring period, the erosion rate could be catalogued as very low. The dual-frequency receiver satisfied the vertical centimetric precision limits for high accurate Digital Elevation Model (DEM), making it a reliable and accurate option to validate erosion studies in small areas.Research highlights: The results have allowed the characterization of multi-annual spatial redistribution of the topsoil at local scale, being of great help to design future prevention actions for the “tillage erosion” in olive grove environments. However, more tests are needed to guarantee the feasibility of low-cost receivers.Ítem Risk Evaluation of the Sanalona Earthfill Dam Located in Mexico Using Satellite Geodesy Monitoring and Numerical Modeling(MDPI, 2023) Vázquez-Ontiveros, J. René; Ruiz-Armenteros, Antonio Miguel; de-Lacy, Maria Clara; Gaxiola-Camacho, José Ramon; Anaya-Díaz, Miguel; Vázquez-Becerra, EstebanDams are essential structures in the growth of a region due to their ability to store large amounts of water and manage it for different social activities, mainly for human consumption. The study of the structural behavior of dams during their useful life is a fundamental factor for their safety. In terms of structural monitoring, classic terrestrial techniques are usually costly and require much time. Interferometric synthetic aperture radar (InSAR) technology through the persistent scatterer interferometry (PSI) technique has been widely applied to measure millimeter displacements of a dam crest. In this context, this paper presents an investigation about the structural monitoring of the crest of the Sanalona dam in Mexico, applying two geodetic satellite techniques and mathematical modeling to extract the risk of the dam–reservoir system. The applicability of the InSAR technique for monitoring radial displacements in dams is evaluated and compared with both GPS systems and an analytical model based on the finite element method (FEM). The radial displacements of the Sanalona dam follow a seasonal pattern derived from the reservoir level, reaching maximum radial magnitudes close to 13 mm in November when the rainy season ends. GPS recorded and FEM simulated maximum displacements of 7.3 and 6.7 mm, respectively. InSAR derived radial displacements, and the reservoir water level presented a high similarity with a correlation index equal to 0.8. In addition, it was found that the Sanalona dam presents the greatest deformation in the central zone of the crest. On the other hand, based on the reliability analysis, the probability of failure values lower than 8.3 × 10−2 was obtained when the reservoir level was maximum, which means that the radial displacements did not exceed the limit states of the dam–reservoir system in the evaluated period. Finally, the extracted values of the probability of failure demonstrated that the Sanalona dam does not represent a considerable risk to society.