Intruding magma brings high temperatures close to the surface, thus offering possibilities for harnessing large amounts of heat for geothermal exploitation. Mount Aso in southern Japan showed frequent volcanic activity during 2016, accompanied by significant earthquake activities with tens of thousands of aftershocks (Kumamoto sequence). Here we investigate the influence of earthquake/volcanic activity on the future productivity of nearby geothermal power plants to determine whether the activity is detrimental or beneficial to energy exploitation. Model results show an increase in $${\text {CO}}_2$$CO2 pressure and temperature with a spatio-temporal correlation between modeled earthquake locations and aftershock decay rates along the entire sequence, showing that seismic activity opened pre-existing vertical cracks providing pathways for the ascending magma. Interestingly, the minor but still significant eruption of Mount Aso in October 2021 may have enhanced future geothermal power generation, indicating a vigorous and active system, possibly increasing the future geothermal power production.

In 2016, a series of large normal faulting earthquakes in the Apennines filled the seismic gap between the 1997 Colfiorito and 2009 L’Aquila earthquakes. These earthquakes, known as the Amatrice‐Visso‐Norcia (AVN) sequence, spawned hundreds of thousand of aftershocks in the first year, extending about 60 km along strike. The Colfiorito and L’Aquila aftershocks showed a significant high fluid‐pressure component in their aftershock genesis, and here we show evidence that the AVN aftershocks also include a significant high pressure CO₂ component. This CO₂ is both deeply‐derived, and internally generated by thermal decomposition. Using a simple model of non‐linear diffusion with a source term, we compare model results with the observed cumulative number of aftershocks, and also spatial comparisons between the calculated fluid pressure and the hypocenters of about 35,000 well‐located events. The good comparisons between model and observations provide evidence that the AVN sequence includes a contribution (additional fluid source) from co‐seismic decarbonization. Our results suggest that internal fluid generation through devolitization or decarbonization is responsible for non‐Omori type aftershock behavior such as observed for the AVN sequence and for the 2011 M_w 9.1 Tohoku (Japan) and the 2014 Iquique (Chile) M_w 8.2 megathrust subduction zone earthquakes.

Rainfall-induced landslides are a disastrous natural hazard causing loss of life and significant damage to infrastructure, farmland and housing. Hydromechanical models are one way to assess the slope stability and to predict critical combinations of groundwater levels, soil water content and precipitation. However, hydromechanical models for slope stability evaluation require knowledge about mechanical and hydraulic parameters of the soils, lithostratigraphy and morphology. In this work, we present a multi-method approach of site characterization and investigation in combination with a hydromechanical model for a landslide-prone hillslope near Bonn, Germany. The field investigation was used to construct a three-dimensional slope model with major geological units derived from drilling and refraction seismic surveys. Mechanical and hydraulic soil parameters were obtained from previously published values for the study site based on laboratory analysis. Water dynamics were monitored through geoelectrical monitoring, a soil water content sensor network and groundwater stations. Historical data were used for calibration and validation of the hydromechanical model. The well-constrained model was then used to calculate potentially hazardous precipitation events to derive critical thresholds for monitored variables, such as soil water content and precipitation. This work introduces a potential workflow to improve numerical slope stability analysis through multiple data sources from field investigations and outlines the usage of such a system with respect to a site-specific early-warning system.

Carbon Capture and Storage (CCS) technologies play a critical role in achieving global and Swiss climate goals, particularly with Switzerland aiming to domestically store some of its residual CO ₂ emissions. In situ mineralization presents a promising avenue for stable and permanent CO ₂ sequestration. This study aims to evaluate the potential of CO ₂ storage via in situ mineralization in the Swiss underground. A set of technical/geological criteria was defined and used to identify, evaluate, and classify the various geological formations. The selected areas identified and evaluated include alpine tectonic units with large volumes of mafic and ultramafic rocks. Despite the presence of suitable rock types, these units are marked by alpine deformation with highly complex structures, rock mixtures, and complex bedrock hydrogeology. The old, altered, and metamorphic nature of the alpine mafic and ultramafic rock formations results in minimal permeability and porosity, consequently impeding CO ₂ injectivity and mineralization kinetics, particularly given the low average geothermal gradient. Additionally, challenges related to water resource requirements, storage site location and accessibility, financial costs, regulation, social acceptance, and environmental impacts further impact feasibility negatively. This study concludes that CO ₂ sequestration via in situ mineralization in the Swiss context is unfeasible in the near term and possibly unsuitable in the long one.