Geosciences

The 2023 Al Haouz earthquake (Mw 6.7–6.9) is the strongest quake ever recorded in modern Morocco and ranks among North Africa’s most significant seismic events of the century. It struck the High Atlas region, causing widespread land changes, thousands of landslides, destruction in remote mountain villages, and heavy losses of life and cultural heritage. The earthquake not only had immediate humanitarian and economic effects but also dramatically transformed the landscape, uncovered new geological features, and reshaped the region—providing a unique opportunity to study seismic activity as geoheritage. Researchers have begun systematically documenting how this earthquake affected perceptions of seismic hazards in the High Atlas area. Although often considered a dark geoheritage, the event holds valuable lessons that can inform programs to strengthen resilience to geohazards. This research places the 2023 Al Haouz earthquake in a geoheritage context, underscoring its scientific, educational, and cultural importance. By analyzing how the earthquake altered the terrain, exposed tectonic activity, and left lasting geological marks, this work aims to bridge the gap between the high scientific interest in seismic events and their limited roles in geoheritage, conservation, tourism, and education.

The Eastern Cordillera of the Colombian Andes is a high-elevation asymmetric plateau subjected to NW–SE shortening. An interesting aspect of this plateau is the presence of high geothermal gradients (up to 52 °C/km), constrained by wells drilled in sedimentary basins. Radial and transverse receiver functions were computed at key sites in the plateau and the adjacent low-elevation foreland region to better understand the controlling factors of these anomalous gradients. Results indicate the presence of tilted anisotropic layers in the uppermost crust of the Cordillera, and nonexistent to weak anisotropy in the foreland region. The estimated SE fast-axis trend of the anisotropy is related to NNE-striking faults and top-to-the-east tectonic transport during deformation. We interpret the SE fast axis as being associated with shearing of NW-dipping faults in the plateau. Compiled thermochronological data point to high deformation and exhumation rates since the middle Miocene, which we use to propose that the rapid rise of deep and hot blocks along major regional faults is perturbing the background geothermal gradient. Regions near major thrust faults in the Eastern Cordillera are potential areas for geothermal energy exploration due to the perturbed geothermal gradient and enhanced fluid infiltration related to deep fault systems.

Knowledge of the trace element contents of petroleum can improve crude oil exploration and refining and aid environmental studies. Analytical challenges prompt experimentation with various digestion methods and analytical techniques, but the assessment of the efficiency of applied methodologies is hindered by the scarcity of multi-element standard reference materials. In this study, NIST SRM 1634c residual fuel oil and NIST RM 8505 crude oil were subjected to (i) hotplate acid digestion and (ii) one, two or three cycles of microwave acid digestion, and analyzed by ICP-MS. Comparison with the few available certificate values shows optimum recoveries for both reference materials with two and three cycles of microwave digestion. Hotplate digestion can also efficiently decompose petroleum, although this procedure requires more time and reagents than the microwave digestion. To better characterize the trace element composition of the two reference materials for future use in the community, we integrate our new results with a comprehensive compilation of published trace element data for both petroleum samples. Finally, we show that the V/Ni and V/(V + Ni) ratios commonly used for oil–oil and oil–source rock correlations remain sufficiently close to the expected ratios even in cases of incomplete digestion with lower recoveries for both elements.