We describe a virtual geological mapping course implemented in response to travelling and social restrictions derived from the ongoing COVID-19 pandemic. The course was designed to replicate a physical mapping exercise as closely as possible with the aid of real field data and photographs collected by the authors during previous years in the Cantabrian Zone (NW Spain). The course is delivered through Google Earth via a KMZ file with outcrop descriptions and links to GitHub-hosted photographs.

The energy transition requires operations in faulted rocks. To manage the technical challenges and public concern over possible induced earthquakes, we need to quantify the risks. We calculate the probability of fault slip based on uncertain inputs, stresses, fluid pressures, and the mechanical properties of rocks in fault zones. Our examples highlight the specific gaps in our knowledge. Citizen science projects could produce useful data and include the public in the discussions about hazards.

Hydraulic rock properties such as porosity and permeability are relevant factors that have an impact on groundwater resources, geological repositories and fossil fuel reservoirs. We investigate the influence of chemical compaction upon the porosity evolution in salt–biotite mixtures and related transport length scales by conducting laboratory experiments in combination with 4-D analysis. Our observations invite a renewed discussion of the effect of sheet silicates on chemical compaction.

We propose a methodology useful to evaluate (1) the reliability of a focal mechanism solution inferred by the inversion of seismological data and (2) the performance of a seismic network, operated to monitor natural or induced seismicity, to assess focal mechanism solutions. As a test case, we studied the focal mechanism reliability by using synthetic data computed for ISNet, a local seismic network monitoring the Irpinia fault system (southern Italy).

The present study shows evidence of fault systems (large cracks in the Earth's crust) hundreds to thousands of kilometers long and several kilometers thick extending from northwestern Russia to the northern Norwegian Barents Sea and the Svalbard Archipelago using seismic, magnetic, and gravimetric data. The study suggests that the crust in Svalbard and the Barents Sea was already attached to Norway and Russia at ca. 650–550 Ma, thus challenging existing models.

This work analyses the density structure of the continental forearc in the northern segment of the 1960 M_w 9.6 Valdivia earthquake. Results show a segmentation of the continental wedge along and perpendicular to the margin. The extension of the less rigid basement units conforming the marine wedge and Coastal Cordillera domain could modify the process of stress loading during the interseismic periods. This analysis highlights the role of the overriding plate on the seismotectonic process.

Geological carbon sequestration using basalts provides a solution to mitigate the high CO₂ concentration in the atmosphere. Due to the long timespan of the GCS, it is important to understand the long-term deformation of the reservoir rock. Here, we studied the creep of basalt with fluid presence. Our results show presence of fluid weakens the rock and promotes creep, while the composition only has a secondary effect and demonstrate that the governing creep mechanism is subcritical microcracking.

A fiber-optic cable was installed along a freely suspended rod in a deep geothermal well in Munich, Germany. A cold-water injection test was monitored with fiber-optic distributed acoustic and temperature sensing. During injection, we observe vibrational events in the lower part of the well. On the basis of a mechanical model, we conclude that the vibrational events are caused by thermal contraction of the rod. The results illustrate potential artifacts when analyzing downhole acoustic data.

We investigated the 1-D velocity structure of the Earth's crust in the NW Dinarides with inversion of arrival times from earthquakes. The obtained velocity models give a better insight into the crustal structure and show velocity variations among different parts of the study area. In addition to general structural implications and a potential for improving further work, the results of our study can also be used for routine earthquake location and for detecting errors in seismological bulletins.

The Pollino region is a highly seismic area of Italy. Increasing the geological knowledge on areas like this contributes to reducing risk and saving lives. We reconstruct the 3D model of the faults which generated the 2010–2014 seismicity integrating geological and seismological data. Appropriate relationships based on the dimensions of the activated faults suggest that they did not fully discharge their seismic potential and could release further significant earthquakes in the near future.

One of the main numerical methods to solve the mass, momentum, and energy conservation equations in geodynamics is the finite-element method. Four main types of elements have been used in the past decades in hundreds of publications. For the first time we compare results obtained with these four elements on a series of geodynamical benchmarks and applications and draw conclusions as to which are the best ones and which are to be preferably avoided.

We present high-resolution tomography images of upper mantle structure beneath the E Alps and the adjacent Bohemian Massif. The northward-dipping lithosphere, imaged down to ∼200 km beneath the E Alps without signs of delamination, is probably formed by a mixture of a fragment of detached European plate and the Adriatic plate subductions. A detached high-velocity anomaly, sub-parallel to and distinct from the E Alps heterogeneity, is imaged at ∼100–200 km beneath the southern part of the BM.