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Comparison between fossil and analogue active geothermal systems permit to obtain key-parameters to define a conceptual model of the area under exploration. The approach is based on structural, kinematic, and fluid inclusions analyses. The fossil system is investigated to describe the distribution of the hydrothermal mineralization as witness of the fluid flow through geological structures and bodies, at depth. Structural and kinematic data (to define the preferential direction of fluid flow) are collected in structural stations and by scan lines and scan boxes on key outcrops. Distribution, length, width of fractures, and hydrothermal veins bring to evaluate permeability in the fossil system and, by analogy, in the deep roots of the active system. Fluid inclusions analysis shed light on density, viscosity, and temperature of the paleo-fluids. Data integration provides the hydraulic conductivity. In active geothermal systems, fieldwork is addressed to paleo-stress analysis with data from recent faults (<2 Ma), to compare with local focal mechanisms. By this, indications on the present fluid pathways are given. The main advantage resides in obtaining parameters normally got after drilling, thus contributing to strengthen the strategy of exploration, de-risking unsuccessful boreholes.

In many Italian regions, and particularly in southern Italy, karst aquifers are the main sources of drinking water and play a crucial role in the socio-economic development of the territory. Hence, estimating the groundwater recharge of these aquifers is a fundamental task for the proper management of water resources, while also considering the impacts of climate changes. In the southern Apennines, the assessment of hydrological parameters that is needed for the estimation of groundwater recharge is a challenging issue, especially for the spatial and temporal inhomogeneity of networks of rain and air temperature stations, as well as the variable geomorphological features and land use across mountainous karst areas. In such a framework, the integration of terrestrial and remotely sensed data is a promising approach to limit these uncertainties. In this research, estimations of actual evapotranspiration and groundwater recharge using remotely sensed data gathered by the Moderate Resolution Imaging Spectrometer (MODIS) satellite in the period 2000–2014 are shown for karst aquifers of the southern Apennines. To assess the uncertainties affecting conventional methods based on empirical formulas, the values estimated by the MODIS dataset were compared with those calculated by Coutagne, Turc, and Thornthwaite classical empirical formulas, which were based on the recordings of meteorological stations. The annual rainfall time series of 266 rain gauges and 150 air temperature stations, recorded using meteorological networks managed by public agencies in the period 2000–2014, were considered for reconstructing the regional distributed models of actual evapotranspiration (AET) and groundwater recharge. Considering the MODIS AET, the mean annual groundwater recharge for karst aquifers was estimated to be about 448 mm·year−1. In contrast, using the Turc, Coutagne, and Thornthwaite methods, it was estimated as being 494, 533, and 437 mm·year−1, respectively. The obtained results open a new methodological perspective for the assessment of the groundwater recharge of karst aquifers at the regional and mean annual scales, allowing for limiting uncertainties and taking into account a spatial resolution greater than that of the existing meteorological networks. Among the most relevant results obtained via the comparison of classical approaches used for estimating evapotranspiration is the good matching of the actual evapotranspiration estimated using MODIS data with the potential evapotranspiration estimated using the Thornthwaite formula. This result was considered linked to the availability of soil moisture for the evapotranspiration demand due to the relevant precipitation in the area, the general occurrence of soils covering karst aquifers, and the dense vegetation.

Islands are frequently characterised by an economic structure centred on tourism and the service sector. This specialisation has taken different forms and characterisations concerning the chosen or spontaneously developed model. To understand the development choices and patterns, this article analyses sixteen islands and archipelagos in the European Union over ten years from 2010 to 2019. A panel data analysis was based on critical variables identifying the tourism industry model from those that could represent a proxy of the community-based tourism model. The principal component analysis was adopted to compare the evolutionary trends of these two different ways of choosing the island's tourism model. Findings identified before the COVID-19 pandemic crisis include two island clusters. One group of islands followed a spontaneous tourism model based on the local community and small or micro hospitality systems, with auto-entrepreneurship in tourism. The second group of islands followed a planning and industry-based tourist model with an employment system and a relevant hospitality industry. Both paradigms have limitations and identify two different tourism evolutionary scenarios useful for the EU's future island tourism policies.

Tourism seasonality as a tourist demand concentration in specific seasons is still a big challenge for Mediterranean islands’ tourism policies. Overtourism occurs during high tourist seasons, and undertourism occurs during low tourist seasons, creating undesirable economic, social, and environmental effects on sustainability. However, the imbalance of tourism demand, specifically in fragile territories such as islands, needs specific policies based on scientific evidence. This article examines tourism seasonality dynamics in the Mediterranean islands, thoroughly analysing tourist overnights on island destinations. The adopted methodology uses a set of statistical indicators, such as peak factor intensity, calculated in a time series analysis from 2008 to 2018. The results of this article allow us to understand the importance for the Mediterranean islands to plan a resilient, sustainable, and harmonious tourism policy, using strategies to contain seasonal peaks and creating new tourist demand in the low season months.

Biomonitoring is a widely employed approach to track changes in the environment. Its use to assess the impact of geothermal energy exploitation for power production is comparatively minor, and largely referred to Tuscany, Italy, geothermal fields. Most examples describe impacts on vegetation, particularly lichens. Biomonitoring proved useful as a tool to reveal the distribution of specific contaminants (e.g., mercury and H 2 S), and as an overall indicator of the impact on ecosystems. In consideration of the comparatively low cost/benefit ratio, the use of biomonitoring should be encouraged. In particular, it could prove useful to establish the natural background prior to development of geothermal exploitation, and to document any subsequent change.

Climate change is a critical sustainability challenge for islands and their main economic sectors. Rising sea levels, extreme temperatures, and drier conditions are the impacts with the most significant potential to amplify the economic damage on islands. However, their isolation and natural conditions bring about some leeway to respond to climate impacts on their terms. This paper aims to provide a local-level analysis and ranking of alternative adaptation pathways in an island context through the stakeholders’ lens. This study reviews the latest advancements in adaptation science and proposes a catalogue of adaptation and risk management options that feed a participatory assessment and ranking by local stakeholders. The research was conducted on the island of Sicily (Italy) and saw the participation of high-level experts and tourism, energy, and maritime transport representatives. It employs a sequential process of four ordered steps oriented towards adaptation planning and stakeholders’ engagement. The process reveals breaches between what stakeholders’ would prioritise when designing policy pathways and their opinion about the most beneficial and balanced adaptation programmes across the sustainability criteria. Results indicate that, according to stakeholders, the priorities are to prepare the energy, tourism, and maritime transport sectors to confront future climate-related events more efficiently. Other transformational actions to ensure long-term social-ecological resilience, which requires significant structural changes and substantial investments, are not at the core of the public needs.

The iron-oxide-copper-gold (IOCG) skarns of the Tatatila-Las Minas mining district in central Mexico represent a structurally-controlled, exhumed fossil geothermal system located in the eastern sector of the Trans-Mexican Volcanic Belt (TMVB). The district was historically exploited for gold and copper mineralization. The emplacement of the ore bodies was controlled by regional Neogene–Quaternary NE- and NW-striking fault systems formed during the extensional evolution of the TMVB. These faults acted as conduits for high-temperature hydrothermal fluids circulating during the cooling of the Neogene magmatic intrusions. By integrating detailed field study with available exploration borehole data, the spatial distribution of the skarn bodies was reconstructed. Three main emplacement geometries were identified: (a) at contacts between magmatic bodies and host rocks, (b) as lenticular or irregular bodies parallel to the host rock foliation, and (c) at the intersections of near-orthogonal faults. Although structural controls on skarn formation represent a key factor in ore emplacement, their analysis remains scarcely explored. This paper therefore contributes to filling this gap by providing a detailed characterization of the structural framework governing IOCG skarn development at Tatatila–Las Minas. The results improve understanding of IOCG systems formation and provide predictive criteria for mineral exploration in similar geological settings, potentially reducing exploration and mining risks.

Seismic faults paradoxically combine high frictional strength, which promotes stress accumulation and should hinder slip, with large seismic displacements. Among proposed dynamic weakening mechanisms, shear heating is crucial because it triggers decarbonation and CO₂ production. In carbonate faults, this process generates transient CO₂ pressurization that can modulate rupture dynamics and promote supershear propagation, yet the amount and pressure of produced CO₂ remain poorly quantified. We investigate carbonate faults in the Apennines, Italy, a region affected by Mw≤7.1 earthquakes. Integrating nano-scale observations of fault surfaces with mineralogical and isotopic constraints, we develop a stoichiometric-thermodynamic model linking seismic decarbonation to Mw 5.9–6.5 earthquakes. Individual events can produce up to 12 tons of CO₂, generating quasi-lithostatic pressures ( ~ 196 MPa) under undrained confinement and supra-hydrostatic pressures (76–134 MPa) under drained conditions. Here, we conclude that seismic CO₂ pressurization can sustain dynamic slip and enhance the destructive potential of earthquakes in carbonate terrains. In this study, the authors develop a stoichiometric-thermodynamic model linking seismic decarbonation to Mw 5.9–6.5 earthquakes. They demonstrate that seismic CO₂ pressurization can sustain dynamic slip and enhance the destructive potential of earthquakes.

The CO 2 -rich geothermal fluids produced in the Piancastagnaio geothermal field (Mt. Amiata geothermal area, Southern Tuscany, Italy) show temperatures up to 360°C and pressures of about 200 bar at depths of around 3,500 m (Giolito, Ph.D. thesis, Università degli Studi di Firenze, Italy, pp 1–147, 2005 ). CaCO 3 - and/or SiO 2 -dominated scales are deposited in the pipes leading to the pressure and atmospheric separators of the geothermal wells. High content of metastibnite and/or stibnite in both calcite and silica scales and Sb contents of up to 50 mg/L in the fluids indicate their mineralising potential. The red or black colours of the scales depend on the predominance of red metastibnite or black stibnite, respectively. In our condensation experiments, as well as during deposition of the scales, metastibnite is the first Sb 2 S 3 mineral to form. In a second stage, metastibnite is transformed to stibnite. During depressurization the Hg content of geothermal fluids partitions preferentially into the gas phase, whereas Sb and As remain in the liquid phase. This separation explains the often observed areal separation of Hg and Sb mineralization. The multistage deposition of Sb in the mining district of Tuscany is due to a periodic restoration of the permeability of the ore-bearing faults by microseismic events and subsequent host rock brecciation. The still ongoing microseismic events are induced by the accumulation of high-pressure CO 2 -rich fluids along faults followed by mechanical failure of the faults.