Magnetic anomalies and deep structure of the Monchique Alcaline Complex (South Portuguese Zone)

Las anomalías magnéticas en el suroeste de la Península Ibérica están caracterizadas por un gran dipolo N-S alargado en dirección E-O. Los valores más intensos de anomalía están relacionados con los afloramientos de sienitas del Complejo Alcalino de Monchique, que intruyen rocas metapelíticas de la Zona Sudportuguesa. Se han realizado medidas de intensidad total de campo magnético a lo largo de un perfil N-S (Portimão-Odemira) que atraviesa dicho dipolo.Además, en los lugares en los que el cuerpo intrusivo de Monchique aflora, se ha medido su susceptibilidad magnética (0,029 SI). La modelización simultánea de las anomalías aeromagnéticas y magnéticas de campo ha permitido determinar la geometría y extensión en profundidad del Complejo Alcalino de Monchique. Este cuerpo tiene una sección asimétrica, aproximadamente lenticular, que se extiende hacia el N. El máximo espesor es superior a 3 km y se alcanza en la parte S, en el sector donde afloraMagnetic anomalies in the southwestern zone of the Iberian Peninsula are characterized by a large N-S dipole elongated in E-W direction. The most intense anomaly values are related to the outcropping sienites of the Monchique Alkaline Complex, intruding the metapelitic host rock of the South Portuguese Zone. Total field magnetic intensity data have been acquired along a N-S profile (Portimão-Odemira) across the dipole. Moreover, magnetic susceptibility of the outcropping Monchique rocks has been measured (0.029 SI). Simultaneous modeling of aeromagnetic and field magnetic data may constrain the geometry and depth extension of the Monchique Alkaline Complex. It has roughly lenticular and asymmetrical section extending in depth towards the north. The maximum thickness of more than 3 km is reached in the southern side of the profile where the intermediate rocks outcro

Structure of the Ugíjar Basin using gravity and magnetic data (Internal Zones, Central Betic Cordillera)

Nuevas medidas gravimétricas y magnéticas adquiridas en la Cuenca de Ugíjar contribuyen a determinar el espesor de su relleno sedimentario y las estructuras que deforman las rocas sedimentarias y el basamento. La combinación de los resultados gravimétricos con datos geológicos de superficie confirma la asimetría de la cuenca, condicionada por el funcionamiento, en su borde sur, de fallas ENE-OSO y componente dextrorsa-normal. En el borde norte, el techo del basamento profundiza con pendiente regional constante hacia el sur aunque hay estructuras tectónicas que deforman el relleno sedimentario. La existencia de dipolos magnéticos de pequeña entidad en el sector N está probablemente relacionada con mineralizaciones metálicas discontínuas asociadas al contacto Alpujárride/Nevado-FilábrideNew gravity and magnetic data reveal the geometry and thickness of the Ugíjar basin infill and provide additional information about the tectonic structures that deform both the basin and the basement rocks. As previous geological data suggested, the basin is asymmetric and highly conditioned by the activity of ENE-WSW trending faults with right-lateral/normal kinematics that are located in the southern border of the basin. At the northern boundary, the basement top dips smoothly southwards, although there are minor tectonic structures that deform up to the sedimentary infill. Magnetic dipoles have been detected in the northern part of the studied sector, probably associated with small and disperse metallic mineralizations deposited along the Alpujárride/Nevado-Filábride contac

Monitorización de infraestructuras críticas expuestas a riesgos naturales y antrópicos mediante interferometría radar de satélite

[EN] Synthetic Aperture Radar Interferometry (InSAR) is a remote sensing technique very effective for the measure of smalldisplacements of the Earth’s surface over large areas at a very low cost as compared with conventional geodetictechniques. Advanced InSAR time series algorithms for monitoring and investigating surface displacement on Earth arebased on conventional radar interferometry. These techniques allow us to measure deformation with uncertainties of 1mm/year, interpreting time series of interferometric phases at coherent point scatterers (PS) without the need for humanor special equipment presence on the site. By applying InSAR processing techniques to a series of radar images over thesame region, it is possible to detect line-of-sight (LOS) displacements of infrastructures on the ground and therefore identifyabnormal or excessive movement indicating potential problems requiring detailed ground investigation. A major advantageof this technology is that a single radar image can cover a major area of up to 100 km by 100 km or more as, for example,Sentinel-1 C-band satellites data cover a 250 km wide swath. Therefore, all engineering infrastructures in the area, suchas dams, dikes, bridges, ports, etc. subject to terrain deformation by volcanos, landslides, subsidence due to groundwater,gas, or oil withdrawal could be monitored, reducing operating costs effectively. In this sense, the free and open accessCopernicus Sentinel-1 data with currently up to 6-days revisit time open new opportunities for a near real-time landmonitoring. In addition, the new generation of high-resolution radar imagery acquired by SAR sensors such as TerraSARX,COSMO-SkyMed, and PAZ, and the development of multi-interferogram techniques has enhanced our capabilities inrecent years in using InSAR as deformation monitoring tool. In this paper, we address the applicability of using spaceborneSAR sensors for monitoring infrastructures in geomatics engineering and present several cases studies carried out by ourgroup related to anthropogenic and natural hazards, as well as monitoring of critical infrastructures.[ES] La interferometría radar de apertura sintética (InSAR) es una técnica de teledetección muy eficaz para medir pequeños desplazamientos de la superficie terrestre en grandes áreas a un coste muy pequeño en comparación con las técnicas geodésicas convencionales. Los algoritmos avanzados de series temporales InSAR para monitorizar e investigar el desplazamiento de la superficie terrestre se basan en la interferometría radar convencional. Estas técnicas nos permiten medir la deformación con incertidumbres de un milímetro por año, interpretando series temporales de fases interferométricas en retrodispersores puntuales coherentes (PS) sin necesidad de presencia humana o de equipos especiales en el sitio. Al aplicar técnicas de procesamiento InSAR a una serie de imágenes radar de la misma región, es posible detectar desplazamientos de infraestructuras proyectados en la línea de vista del satélite (line-of-sight o LOS) y, por lo tanto, identificar movimientos anormales o excesivos que indiquen problemas potenciales que requieran una investigación detallada del terreno. Una de las principales ventajas de esta tecnología es que una sola imagen radar puede cubrir un área importante de hasta 100 km por 100 km o más, ya que, por ejemplo, los datos de los satélites de banda C Sentinel-1 cubren una franja de 250 km de ancho. Por lo tanto, todas las infraestructuras civiles de la zona, como presas, diques, puentes, puertos, etc., sujetas a deformaciones del terreno por actividad volcánica, deslizamientos de tierra, hundimientos por extracción de agua subterránea, gas o petróleo, podrían ser monitorizados, reduciendo los costes operativos de manera efectiva. En este sentido, los datos Sentinel-1 de Copernicus, de acceso abierto, con hasta 6 días de tiempo de revisión actual abren nuevas oportunidades para una monitorización terrestre casi en tiempo real. Además, la nueva generación de imágenes radar de alta resolución adquiridas por sensores SAR como TerraSAR-X, COSMOSkyMed y PAZ, y el desarrollo de técnicas multi-interferograma ha mejorado nuestras capacidades en los últimos años en el uso del InSAR como herramienta para el control de deformaciones. En este trabajo se aborda la aplicabilidad del uso de sensores SAR espaciales para la monitorización de infraestructuras civiles en ingeniería geomática y presentamos varios casos de estudio realizados por nuestro grupo relacionados con riesgos naturales y antrópicos, así como de monitorización de infraestructura crítica.ERS-1/2 and Envisat datasets were provided by the European Space Agency (ESA). Sentinel-1A/B data were freely provided by ESA through Copernicus Programme. Data have been processed by DORIS (TUDelft), StaMPS (Andy Hooper), SARPROZ (Copyright (c) 2009-2020 Daniele Perissin), and SNAP (ESA). The satellite orbits are from TUDelft and ESA, as well as from the ESA Quality Control Group of Sentinel-1. Research was supported by [ESA Research and Service Support] for providing hardware resources employed in this work; [Spanish Ministry of Economy, Industry and Competitiveness] under ReMoDams project ESP2017-89344-R (AEI/FEDER, UE); [University of Jaén (Spain)] under PAIUJA-2021/2022 and CEACTEMA; [Junta de Andalucía (Spain)] under RNM-282 research group; [ERDF through the Operational Programme for Competitiveness and Internationalisation - COMPETE 2020 Programme] within project «POCI-01-0145-FEDER006961»; [National Funds through the FCT – Fundação para a Ciência e a Tecnologia (Portuguese Foundation for Science and Technology)] as part of project UID/EEA/50014/2013; [The Ministry of Education, Youth and Sports from the National Programme of Sustainability (NPU II)] under project «IT4Innovations excellence in science - LQ1602» (Czech Republic); and [Slovak Grant Agency VEGA] under projects No. 2/0100/20Ruiz-Armenteros, A.; Delgado-Blasco, J.; Bakon, M.; Lazecky, M.; Marchamalo-Sacristán, M.; Lamas-Fernández, F.; Ruiz-Constán, A.... (2021). Monitoring critical infrastructure exposed to anthropogenic and natural hazards using satellite radar interferometry. En Proceedings 3rd Congress in Geomatics Engineering. Editorial Universitat Politècnica de València. 137-146. https://doi.org/10.4995/CiGeo2021.2021.12736OCS13714

Las acequias de careo de Sierra Nevada (sur de España), un sistema de recarga ancestral en acuíferos de alta montaña

En las partes altas de Sierra Nevada (sur de España) se realiza, desde época andalusí (Edad Media), un Sistema Integrado de Gestión del Agua Subterránea, en el que las acequias de careo constituyen un elemento clave. Estos canales excavados en el terreno están diseñados para recargar las aguas procedentes del deshielo, a lo largo de su recorrido y en distintas zonas concretas, donde hay una mayor permeabilidad del terreno. Una vez que el agua se infiltra en las partes altas de los valles, pasa a circular lentamente por los acuíferos superficiales y surge por ríos y manantiales situados a media ladera. En este trabajo se presentan los resultados conseguidos mediante el monitoreo e investigación hidrogeológica de una cuenca de 68 km2 (cuenca del río Bérchules), situada en Sierra Nevada, donde se aplica la técnica de careo. Los resultados conseguidos han permitido comprobar que el careo aplana el hidrograma de los ríos de alta montaña, reduciendo su componente nival y aumentando la subterránea. Además contribuye a mantener el caudal de los manantiales y los ecosistemas asociados a esta descarga. Su uso en otras zonas de alta montaña permitiría disponer de una excelente herramienta de adaptación al cambio climático.Instituto Geológico y Minero de España, EspañaUniversidad Politécnica de Cataluña, EspañaAgencia de Medio Ambiente y Agua de la Junta de Andalucía, EspañaUniversidad Pablo de Olavide, EspañaConsejería de Medio Ambiente y Ordenación del Territorio, Junta de Andalucía, EspañaPeer reviewe

Towards 3D databases and harmonized 3D models at IGME-CSIC

IGME-CSIC has a highly relevant geological and geophysical database that includes a continuous digital geological cartography at 1:50000; 1:200000 and 1:1000000 scales and a fair amount of geophysical data: gravity, magnetic, well-logs in tiff and LAS format, seismic lines in tiff and SEG-Y format, borehole and petrophysical data, together with other geophysical and geological studies. Since the 2004, an important effort has been done to undertake 3D geological and geophysical modelling ranging from local studies (mineral exploration or CO2 storage sites) to regional geology for a better understanding of the subsurface structure and its geodynamic evolution as a base for other studies on natural hazards or mineral resources. These studies were ¿stand alone¿ and now IGME is designing a new strategy. It includes the available data and models harmonization (stratigraphy sequences, structural interpretations, faults distribution, seismic velocity models, spatial distribution of physical properties such as density and magnetic susceptibility, workflows, methodologies, evaluation of uncertainties, visualization, etc.) to comply with the FAIR (Findable, Accessible, Interoperable and Reusable) data standardization. In this way, the new 3D models will be easily integrated and available from the databases. This strategy includes collaboration with the Bureau de Recherches Géologiques et Minières of France (BRGM) and Laboratório Nacional de Energia e Geologia of Portugal (LNEG) in order to harmonize the Spanish geological data and models with their neighbours across national borders. The first step is being done in the framework of GeoERA projects. Plain-language Summary IGME-CSIC owns a large database that includes a highly valuable geological and geophysical data and geophysical studies containing the interpretation of some of the data of Spain (onshore and offshore) Since 2004 the authors of this work have been working in 3D geological and geophysical modelling that includes local (mineral exploration or CO2 storage sites) and regional studies. The goal is to improve our understanding of the subsurface structures and processes as a base for deepening our knowledge in how the natural hazards occur, how to improve the exploration for mineral resources, etc. These studies were made ad hoc within different projects and now IGME-CSIC is designing a workflow to harmonize these models in order to comply with the FAIR (Findable, Accessible, Interoperable and Reusable) data standardization so the models will be available to being used beyond the initial objectives that generated their creation. This strategy includes collaboration with other European institutions like the Bureau de Recherches Géologiques et Minières of France (BRGM) and Laboratório Nacional de Energia e Geologia of Portugal (LNEG) in order to harmonize the models across national borders. The first step is already being done in the framework of the GeoERA projects

Combination of lumped hydrological and remote-sensing models to evaluate water resources in a semi-arid high altitude ungauged watershed of Sierra Nevada (Southern Spain)

Assessing water resources in high mountain semi-arid zones is essential to be able to manage and plan the use of these resources downstream where they are used. However, it is not easy to manage an unknown resource, a situation that is common in the vast majority of high mountain hydrological basins. In the present work, the discharge flow in an ungauged basin is estimated using the hydrological parameters of an HBV (Hydrologiska Byråns Vattenbalansavdelning) model calibrated in a “neighboring gauged basin”. The results of the hydrological simulation obtained in terms of average annual discharge are validated using the VI-ETo model. This model relates a simple hydrological balance to the discharge of the basin with the evaporation of the vegetal cover of the soil, and this to the SAVI index, which is obtained remotely by means of satellite images. The results of the modeling for both basins underscore the role of the underground discharge in the total discharge of the hydrological system. This is the result of the deglaciation process suffered by the high mountain areas of the Mediterranean arc. This process increases the infiltration capacity of the terrain, the recharge and therefore the discharge of the aquifers that make up the glacial and periglacial sediments that remain exposed on the surface as witnesses of what was the last glaciation.Grup d'Hidrologia Subterrànea, Universitat Politècnica de Catalunya, EspañaInstituto Andaluz de Investigación y Formación Agraria, Pesquera, Alimentaria y de la Producción Ecológica de Andalucía, EspañaUnidad de Granada, Instituto Geológico y Minero de España, EspañaUnidad de Zaragoza, Instituto Geológico y Minero de España, EspañaAgencia de Medio Ambiente y Agua de la Junta de Andalucía, EspañaDepartamento de Ciencias Geológicas, Universidad Católica del Norte, Chil

Factors determining subsidence in urbanized floodplains: evidence from MT‐InSAR in Seville (southern Spain)

Major rivers have traditionally been linked with important human settlements throughout history. The growth of cities over recent river deposits makes necessary the use of multidisciplinary approaches to characterize the evolution of drainage networks in urbanized areas. Since under‐consolidated fluvial sediments are especially sensitive to compaction, their spatial distribution, thickness, and mechanical behavior must be studied. Here, we report on subsidence in the city of Seville (Southern Spain) between 2003 and 2010, through the analysis of the results obtained with the Multi‐Temporal InSAR (MT‐InSAR) technique. In addition, the temporal evolution of the subsidence is correlated with the rainfall, the river water column and the piezometric level. Finally, we characterize the geotechnical parameters of the fluvial sediments and calculate the theoretical settlement in the most representative sectors. Deformation maps clearly indicate that the spatial extent of subsidence is controlled by the distribution of under‐consolidated fine‐grained fluvial sediments at heights comprised in the range of river level variation. This is clearly evident at the western margin of the river and the surroundings of its tributaries, and differs from rainfall results as consequence of the anthropic regulation of the river. On the other hand, this influence is not detected at the eastern margin due to the shallow presence of coarse‐grain consolidated sediments of different terrace levels. The derived results prove valuable for implementing urban planning strategies, and the InSAR technique can therefore be considered as a complementary tool to help unravel the subsidence tendency of cities located over under‐consolidated fluvial deposits. Copyright © 2017 John Wiley & Sons, Ltd.Departamento de Geodinámica, Universidad de Granada, EspañaDepartamento de Ingeniería Cartográfica, Geodésica y Fotogrametría, Universidad de Jaén, EspañaCentro de Estudios Avanzados en Ciencias de la Tierra (CEACTierra), Universidad de Jaén, EspañaInstituto Andaluz de Ciencias de la Tierra, Consejo Superior de Investigaciones Científicas, EspañaInstituto Andaluz de Ciencias de la Tierra, Universidad de Granada, EspañaDepartamento de Ingeniería Civil, Universidad de Granada, EspañaInstitute for Systems and Computer Engineering, Technology and Science, Universidade de Trás‐os‐Montes e Alto Douro, PortugalInstituto Geológico y Minero de España, EspañaDepartment of Radar Technology, Netherlands Organisation for Applied Scientific Research, Países BajosGrupo de Investigación Microgeodesia Jaén, Universidad de Jaén, EspañaDepartment of Geoscience and Remote Sensing, Delft University of Technology, Países Bajo

Integrating current and historical water chemistry data with long-term piezometric records to develop a regional-scale conceptual flow model: Las Salinas spring, Medina del Campo, Spain

Study region: Old Las Salinas spring in Medina del Campo, Duero river basin, central Spain. Study focus: Medina del Campo groundwater body (MCGWB) is a multilayer semiconfined aquifer subject to intensive pumping since the 1970’s, where the current existence of spas where there used to be traditional baths could confirm the existence of deep groundwater flow paths. The old spring of Las Salinas (OSLS) is a saline anomaly in an aquifer with predominance of CaCO3H waters whose occurrence has not yet been formally explained. Long-term geological, geophysical, hydrogeological and hydrochemical records were integrated and complemented with field work to clarify its existence. New hydrological insights for the region: Outcomes led to the conclusion that the hydrochemistry of the Olmedo and Palacio de las Salinas salt baths is associated with the existence of a major threshold in the impervious basement of the aquifer, which intercepted deep regional groundwater flow and caused upwelling to the surface under unperturbed conditions. These results allow for the development of a conceptual flow model at the regional scale that explains the changes in natural water chemistry that have been identified in recent decades

Integrating current and historical water chemistry data with long-term piezometric records to develop a regional-scale conceptual flow model: Las Salinas spring, Medina del Campo, Spain

20 p. - Supplementary material related to this article can be found, in the online version, at doi: https://doi.org/10.1016/j.ejrh.2021.100781.[EN] Study region Old Las Salinas spring in Medina del Campo, Duero river basin, central Spain. Study focus Medina del Campo groundwater body (MCGWB) is a multilayer semiconfined aquifer subject to intensive pumping since the 1970’s, where the current existence of spas where there used to be traditional baths could confirm the existence of deep groundwater flow paths. The old spring of Las Salinas (OSLS) is a saline anomaly in an aquifer with predominance of CaCO3H waters whose occurrence has not yet been formally explained. Long-term geological, geophysical, hydrogeological and hydrochemical records were integrated and complemented with field work to clarify its existence. New hydrological insights for the region Outcomes led to the conclusion that the hydrochemistry of the Olmedo and Palacio de las Salinas salt baths is associated with the existence of a major threshold in the impervious basement of the aquifer, which intercepted deep regional groundwater flow and caused upwelling to the surface under unperturbed conditions. These results allow for the development of a conceptual flow model at the regional scale that explains the changes in natural water chemistry that have been identified in recent decades.This research has received funding from the European Union H2020 Programme under Grant Agreement No. 730497 for the research project NAIAD-NAture Insurance value: Assessment and Demonstration.Peer reviewe

Levelling Profiles and a GPS Network to Monitor the Active Folding and Faulting Deformation in the Campo de Dalias (Betic Cordillera, Southeastern Spain)

The Campo de Dalias is an area with relevant seismicity associated to the active tectonic deformations of the southern boundary of the Betic Cordillera. A non-permanent GPS network was installed to monitor, for the first time, the fault- and fold-related activity. In addition, two high precision levelling profiles were measured twice over a one-year period across the Balanegra Fault, one of the most active faults recognized in the area. The absence of significant movement of the main fault surface suggests seismogenic behaviour. The possible recurrence interval may be between 100 and 300 y. The repetitive GPS and high precision levelling monitoring of the fault surface during a long time period may help us to determine future fault behaviour with regard to the existence (or not) of a creep component, the accumulation of elastic deformation before faulting, and implications of the fold-fault relationship