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Cities in Spain use to be overgrown around old towns (preroman, roman and medieval) constructed on topographic defensive heights of singular geological features. In the upper Guadalquivir valley, a tabular body of Miocene sediments has been eroded forming mesas where most of its population has been living since middle age. As the towns grew, new neighborhoods settled towards the edges and cliffs of these mesas, in areas with high probabilities of instability. The town of Arjona is a good example of this geological-urbanistic setup, located on the tabular hill formed by clay marls topped by bioclastic limestones that protect it from erosion. Modern buildings from few sectors of the town show important cracks, even the 16th century bell-tower has a 4º inclination indicating problems in the foundations. Multi-temporal SAR interferometry (MT-InSAR) is a powerful technique to derive displacement time series over coherent targets on the Earth associated with geophysical or structural instabilities phenomena. In this work we use MT-InSAR with Sentinel-1 data to reveal that, at present day, the periphery of Arjona is active, being recognized a large landslide in the south side of this mesa town which affects buildings and civil infrastructures. In addition, field work is being carried out to investigate the sources of these instabilities.

Careo channels are ancestral Nature-Based Solutions for water management that are used to recharge aquifers in the watershed of the Sierra Nevada Mountain massif (Spain). These hand-dug channels divert snowmelt from the headwaters of rivers and let it infiltrate into the upper parts of the hill slopes and by that increase the water resources available during the dry season. Our study investigates the role of this ancestral aquifer recharge practice in the Bérchules watershed by comparing its yield with respect to the total recharge of the aquifer during the 2014-2015 hydrological year. For this purpose, we contrast the total recharge of 7.6 hm³, calculated with an HBV watershed model, with flow measurements we conducted in the main channels of the system during this year. Our results show that 52% of the total recharge can be accounted for a spatially distributed recharge by natural infiltration of meteoric waters, while the remaining 48 % originate from waters captured and infiltrated by careo channels. The study highlights the efficiency and importance of this ancestral aquifer recharge system developed in hard rocks, which may be replicated in other high mountain watersheds of similar hydroclimatic and geological characteristics.

Sierra Nevada is the main mountain range in southern Iberian Peninsula and has been catalogued as Biosphere Reserve (1986), Natural Park (1989) and National Park (1999). Apart from its ecological, geomorphological and landscape singularities, there are other hydrological, historical and cultural remarkable features, such as the ancestral water management performed at the river’s headwater. A dense network of channels excavated in the ground, the so-called acequias de careo, allows the derivation of melting water from of the river waterhead towards the higher zone of the hillsides, where it infiltrates. It slowly flows down through the weathered zone of the metamorphic rocks, until reaching the rivers and springs used for supply and irrigation. This water management system, implemented since the Muslim conquest of southern Spain (VIII century), has led to a remarkable landscape transformation, where agricultural terraces and pastures coexist with ecosystems of high ecological value. This paper describes the careos water management technique in a pilot basin, the Bérchules watershed, recently studied during 2014 and 2015 by the Geological Survey of Spain. Migration, the abandonment of cultivated lands and, consequently, of the acequias de careo are affecting the dynamics of the rivers, endangering the delicate balance reached between the man and the nature in Sierra Nevada, after many centuries of harmonious coexistence.

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 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.

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.

This research was undertaken as part of the project "Impact, monitoring and assessment of global and climate change on water resources in high-mountain National Parks (CCPM) ", with reference number CANOA-51.3.00.43.00 and funded by Organismo Autonomo Parques Nacionales from the Ministerio para la Transicion Ecologica y el Reto Demografico. The authors thank the Ibero-American Science and Technology for Devel-opment Programme (CYTED) for its financial support to the network "Wa-ter Sowing and Harvesting in Protected Natural Areas" (419RT0577) . This work is a contribution to the Research Group RNM-126 of the Junta de Andalucia. Special thanks goes to the irrigation community in Berchules and the Sierra Nevada National Park for their collaboration. We also appre-ciate the support of AEMET and REDIAM, who provided meteorological and hydrological data. The authors would also like to thank the anonymous reviewers for their constructive comments and suggestions which led to a substantial improvement of the paper., 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 fromthe headwaters of river basins and distributing it throughout the upper parts of the slopes. Thismethod 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., Organismo Autonomo Parques Nacionales CANOA-51.3.00.43.00, Ibero-American Science and Technology for Devel-opment Programme (CYTED) 419RT0577 RNM-126, Junta de Andalucia

We investigated speleogenetical processes and the formation of unusual endo- and exokarstic features within carbonates rocks in the Sierra de Mollina mountain range (southern Spain), a sector affected by salt tectonics. Allochthonous Triassic evaporites partially overlie younger subsalt Jurassic limestones and dolostones. The carbonate beds show signs of karstification, including large collapse structures and a dense field of collapse sinkholes. We focus our study on the two deepest cavities (~100 m deep), namely Sima del Soldado and Órganos Cave, where significant secondary gypsum (CaSO·2HO) and traces of mineralogical associations (alunite, jarosite, barite and others) have been reported. We analyzed the sulfur (δS) and oxygen (δO) of the gypsum sulfate and the δO and δD of its structural water. Our results suggest that reduction of sulfates from the Upper Triassic evaporites generated hydrogen sulfide (HS). Subsequently, sulfuric acid (HSO) was generated in oxic conditions, which triggered sulfuric acid speleogenesis (SAS). Our reconstruction of the isotopic composition of the paleo-aquifer using stable isotopes of gypsum hydration water (δO and δD) indicates that gypsum crystallized in a climatic setting colder than present. Gypsum precipitation included acid replacement of the carbonates and hydration of anhydrite (CaSO) generated in previous stages. The overlying Triassic evaporites provided the hydraulic gradient needed to drive sulfate-rich water towards the deeper, O-depleted carbonate aquifer. Sulfate reduction in anoxic conditions generated HS that later mixed with O-enriched waters in the upper carbonate aquifer, creating the sulfuric acid necessary for SAS. The stable isotopes of gypsum from Órganos Cave reveal that the vadose zone was not connected to the surface, probably being confined beneath Triassic evaporitic rocks, while the Sima del Soldado underwent a partial connection with atmospheric O., We would like to thank the members of the Asociación Espeleológica Velezana and Javier Jaén Fajardo from Al Límite Mountain Club in Alameda for their help in cave research. The authors thank Prof. Dr. Juan Manuel García-Ruiz for his comments and suggestions regarding the petrographic study of replacement textures of calcite by gypsum. We thank Dr. Cristobal Verdugo for mineralogical analysis. Dr. Antonio Pedrera was financially supported by the projects FIPs (P20-01387), REViSE (PID2020-119651RB-I00), and A-RNM-005-UGR18. Dr. Fernando Gázquez was financially supported by the “HIPATIA” research program of the University of Almeria. The isotopic analyses of gypsum hydration water were funded by the I + D + I Project PALEOQUANT (PY18-871) of the Junta de Andalucía.

Land surface is in constant motion due to both natural causes and human activity. Over time, many measurement techniques have been developed to study the deformation of the earth's surface. Some of them, despite having different levels of accuracy, are slow and time consuming (e.g., classical geodetic techniques). The introduction of space geodesy techniques such as GNSS systems and SAR remote sensing have offered new opportunities for precision deformation control in the field of space geodesy. In particular, using satellite radar interferometry (InSAR) as an Earth Observation routine technique, the deformation of large areas of the terrain can be monitored providing displacements at a relatively low cost compared with other ground-based techniques. Nowadays, we are living in the golden age of InSAR as there has never been as much SAR data from different missions as there is today. Of particular importance is the Copernicus program of the European Commission and ESA, which provides us with an inexhaustible source of free SAR data with extraordinary potential for monitoring the earth's surface thanks to the constellation of Sentinel-1 SAR satellites. Thanks to the great capability of SAR remote sensing, many civil infrastructures can be monitored and inspected from space without the need for physical intervention on the ground, greatly reducing costs and execution time. The advanced InSAR time series algorithms allow us to investigate the displacements of these infrastructures with uncertainties of the order of 1 mm/year, interpreting time series of interferometric phases at coherent point reflectors (PS). The use of C-band SAR data from ERS-1/2, Envisat, and Sentinel-1 has allowed us to monitor the southeast of the province of Málaga in southern Spain during the last thirty years, obtaining a deformation pattern of some critical infrastructures in the area. We can highlight, among them: the Limonero dam inaugurated in 1983, whose reservoir regulates the avenues of the Guadalmedina river and serves as a water supplying source for the city of Malaga; the Málaga-Costa del Sol international airport, an important airport for Spanish tourism as it is the main airport serving the Costa del Sol; the Málaga harbor, an industrial area, or some roads and railways. Of special importance is an urban sector with an intensive overexploitation of aquifers. Due to the increase in population because of the expansion of the tourism industry in the Benalmádena coast and Torremolinos area, the aquifers are being affected after the intensive overexploitation of groundwater with the consequent subsidence of the terrain, continuous and increased over time. In this contribution, we show our results of the SAR remote sensing application in this area of the southern Spanish coast.

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.

Epikarst – the shallow, surficial part of a karstic massif – has a significant influence on the spatio-temporal variability of recharge and the hydrodynamic functioning of many karst aquifers. In the Mediterranean morphoclimatic zone, the average thickness of a well-developed epikarst is around ten metres, but the spatial patterns of its degree of development are very heterogeneous due to the complex interaction of a number of different factors such as lithology, fracturing, weathering, soil and vegetation. In addition, direct field observation is difficult because good outcropping conditions are restricted to particular locations, some areas are not accessible and the size of the study area is often too large for exhaustive field surveys. Satellite-based remote sensing, however, provides a complete coverage of an entire area with spectral resolutions that detect variability in features that can define image textures related to the development of the epikarst. This paper describes a quantitative methodology for epikarst mapping using satellite images and field data. The proposed method comprises an unsupervised classification to define the spectral signature of each of three epikarst development categories in a high-resolution satellite image followed by a supervised classification of the terrain into one of the three categories on a low spatial resolution scale. The training areas in the field are assigned to the three categories by a panel of experts using the Delphi method. Geophysical data are used for validation to overcome any bias that may be introduced by the panel. The proposed methodology has been applied to the Sierra de las Nieves karstic aquifer (Malaga, southern Spain). The outcome is a map of estimated epikarst development that is an approximation to reality and which can be improved as more experimental data become available.