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his work focuses on two case studies carried out in Spain, where urban geophysics plays an important role in subsurface characterization. The application of geophysical methods in urban scenarios faces several challenges related to environmental noise (seismic or electromagnetic) or logistical constraints (lack of open space, complexity of instrumentation setup). In order to overcome these problems, research efforts are needed on both acquisition and processing aspects. The first case study presents the use of an innovative technology to acquire seismic data in the city of Granada. Distributed Acoustic Sensing (DAS) is based on the measurement of strain rate along a buried optical fiber that provides seismic measurements in a dense array of sensors. In our study, the fiber is a pre-existing underground telecommunications cable that crosses the city from northwest to southeast. We used 10 hours of ambient noise recordings to obtain subsurface reflection images that provide critical information for ground motion studies and seismic hazards in the metropolitan area. The second case study is located in the autonomous city of Melilla (North Africa). In this work, a gravimetric survey was carried out over the urban area with the aim of delineating the bedrock using 3D gravimetric inversion. We integrated the resulting geophysical model with surface geological observations, electrical resistivity tomography sections and borehole data to produce a 3D geological model of the city. Both studies highlight the suitability of geophysical information to complement the urban geological and geotechnical dataset to characterize and image the city underground.

In this study we contrast the results of different geophysical methods in order to describe the karst system surrounding of the Gruta de las Maravillas cave (Aracena, Spain). A comprehensive study of the geophysical responses of the known cavity was carried out, after which several sections were studied to detect the karst architecture and cave continuity. To ensure precision, the inner 3D-topography of the cave was determined by classical geodetic techniques and a digital terrain model was performed with differential GPS. The microgravity method was used to obtain the residual gravity map of the entire study zone, whose minima could be related to caves. Then, the negative gravity anomalies were analyzed to plan several lines for implementing further geophysical methods: magnetic profiles (MP), electrical resistivity tomography (ERT), induced polarization (IP), 2D seismic prospection (refraction tomography and reflection sections) and ground penetrating radar (GPR). The resulting models for each line explored were integrated with detailed geological maps to establish the unknown continuity of the caves. Finally, we discuss the suitability of each geophysical technique for cave detection in marble with sulfur host rock and propose the best procedures to constrain their geometries., Depto. de Geodinámica, Estratigrafía y Paleontología, Fac. de Ciencias Geológicas, TRUE, pub

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, Topo-Iberia, Ministry of Science and Innovation, Unidad Deptal. de Astronomía y Geodesia, Fac. de Ciencias Matemáticas, Instituto de Matemática Interdisciplinar (IMI), TRUE, pub

[EN] This contribution summarizes the geophysical research carried out to characterize the groundwater body (GWB) of Medina del Campo, located in the SE part of the Duero Basin, which corresponds to a multilayer detrital aquifer. The 3D model obtained displays the distribution of Miocene, Paleogene and Cretaceous sediments and the structure of the paleozoic basement in this sector of the basin. The 3D geological model was built with the Geomodeller software and comprises geological mapping, vertical electrical soundings, time domain electromanetic soundings and gravimetric data. An important methodological aspect of this work is the use of gravimetric forward modelling and gravimetric 3D inversion as main tools. The 3D geological model reveals that the subsurface of the Medina del Campo GWB is not homogeneous but is constituted by E-W to ENE-WSW depressions and highs mainly associated with pop-up and pop-down structures. In addition, NE-SW vertical faults developed depressions; like the Villorio-Alba fault with an associated displacement of 850 meters. The maximum depths of the basement are located to the SE part of Medina del Campo and south of Valladolid, where they reach values of more than 2000 m depth. In the surroundings of Medina del Campo, the basement has an EW trend and reaches about 1000 m depth. The Paleogene unit has a more constant sedimentary thickness in the center of the Basin with values of about 500 m, whereas the Miocene one shows greater Variations reaching up to 1500 m of thickness.This 3D geological model represents an important advance in the knowledge of the geometry of this GWB. It will have implications in future flow models of this part of the basin and in the definition of the resources and reserves of this GWB.

[EN]In the highest part of the hill where the monumental complex of the Alhambra and the Generalife is located, in the Dehesa del Generalife (Granada, Spain) there is an extensive hydraulic complex, from the Nasrid period, which could have been fed by groundwater captured from the Aljibe de la Lluvia. This paper presents the results of a geophysical prospecting survey performed to determine if there hydrogeological conditions to explain the presence of a spring in the Alhambra Formation. The results explain why the water emerges in the vicinity of the cistern and contribute to reinforcing the theory that this spring could condition the establishment of the Alberca Rota hydraulic complex, which was the node that made it possible to supply water to the royal Nasrid countryhouses of Alixares (Qasr al-Dishār) and Dār al-'Arūsa (Casa de la Novia), built in the last third of the 14th century., [ES] En la parte más elevada del cerro donde se ubica el conjunto monumental de la Alhambra y el Generalife, en la Dehesa del Generalife (Granada, España) se sitúa un extenso complejo hidráulico, de época nazarí, que pudiera haber sido alimentado por el agua subterránea captada desde el Aljibe de la Lluvia. En este trabajo se presentan los resultados de una campaña de prospección geofísica con la que se ha pretendido determinar si se dan las condiciones hidrogeológicas que expliquen la presencia de un manantial colgado dentro de la Formación Alhambra. Los resultados conseguidos explican por qué surge el agua en las inmediaciones del aljibe y contribuyen a reforzar la teoría que apunta a que este manantial pudo condicionar el establecimiento del complejo hidráulico de la Alberca Rota, que fue el nodo que posibilitó el suministro de agua a las almunias reales nazaríes de los Alixares (Qaṣr al-Dishār) y Dār al-‘Arūsa (Casa de la Novia), construidas en el último tercio del siglo XIV.

[EN] The main goal of the Tectonic Processes and GeoResources Lab is to explore the lithospheric processes operating during extension and orogenesis, and their influence on the distribution of georesource.

This article is composed of three independent commentaries about the state of Integrated, Coordinated, Open, Networked (ICON) principles (Goldman et al., 2021, https://doi.org/10.1002/essoar.10508554.1) in the Geomagnetism, Paleomagnetism, and Electromagnetism (GPE) section and discussion on the opportunities and challenges of adopting them. Each commentary focuses on a different topic: Global collaboration, reproducibility, data sharing and infrastructure; Inclusive equitable, and accessible science: Involvement, challenges, and support of early career, BIPOC, women, LGBTQIA+, and/or disabled researchers; Community engagement, citizen science, education, and stakeholder involvement. Data sharing practices and open repository use still varies strongly between GPE communities. Some have a long tradition of data sharing; others are only starting it. Globally, GPE leadership is strongly dominated by white males and diversity may increase through the creation of Science Equality Commissions. Improved global stakeholder involvement can increase research impacts and help fight inequalities. In all investigated topics we see promising beginnings but also recognize obstacles that include a lack of funding, a lack of understanding of diversity, and prioritizing short-term gain over long-term benefit. Nonetheless, we are hopeful that our community will embrace ICON science

[EN] The acequias de careo are ancestral water channels excavated during the early Al-Andalus period (8th-10th centuries), which are used to recharge aquifers in the watersheds of the Sierra Nevada mountain range (Southeastern Spain). The water channels are maintained by local communities, and their main function is collecting snowmelt, but also runoff from rainfall from the headwaters of river basins and distributing it throughout the upper parts of the slopes. This method of aquifer artificial recharge extends the availability of water resources in the lowlands of the river basins during the dry season when there is almost no precipitation and water demand is higher. This study investigates the contribution of the careo channels in the watershed of Bérchules concerning the total aquifer recharge during the 2014-2015 hydrological year. Several channels were gauged, and the runoff data were compared with those obtained from a semi-distributed hydrological model applied to the same hydrological basin. The natural infiltration of meteoric waters accounted for 52% of the total recharge, while the remaining 48% corresponded to water transported and infiltrated by the careo channels. In other words, the careo recharge system enhances by 92% the natural recharge to the aquifer. Our results demonstrate the importance of this ancestral and efficient channel system for recharging slope aquifers developed in hard rocks. The acequias de careo are nature-based solutions for increasing water resources availability that have contributed to a prosperous life in the Sierra Nevada. Its long history (>1200 years) suggests that the system has remarkable resilience properties, which have allowed adaptation and permance for centuries in drastically changing climatic and socioeconomic conditions. This recharge system could also be applied to -or inspire similar adaptation measures in- semi-arid mountain areas around the world where it may help in mitigating climate change effects.

[EN] Critical gravity and magnetic data suggest the presence of a continuous zigzag exhumed mantle body inside the attenuated crust of the north Iberia continental margin. We propose that this body greatly conditioned the structural domains of the Cantabrian-Pyrenean fold-and-thrust belt during their evolution from hyperextension in Early Cretaceous times to shortening and inversion during the Cenozoic. This may be seen as a new line for cross-section construction and balancing, because previous cross-sections do not incorporate comparable volumes of exhumed mantle. Five structural cross-sections, constrained by the results of 3D gravity inversion, feed our discussion of the complexities of the doubly vergent Pyrenean orogen in view of the inversion of a precursor hyperextended rifted margin. In all sections, crustal rocks underthrust the lithospheric mantle in the hyperextended region, supporting that the near-surface exhumed mantle lithosphere acts as a more rigid buttress, allowing weaker continental material to be expelled outwards and upwards by thrusting during the Alpine collision; thus giving rise to two uplifted crustal triangular zones at the boundaries with the exhumed mantle. Contractional slip is localized in lithospheric-scale thrusts, which in turn reactivate parts of the exten-sional system. The NE-SW transfer zones that offset the rift therefore behave as compartmental faults during the orogenic phase. The amount of shortening increases from 34 km in the Cantabrian Cordillera, where the Bas-que-Cantabrian Basin partially preserves its original extensional geometry, to 135 km in the nappe stack of the central Pyrenees.