Researchers from Utrecht University in the Netherlands have discovered the causes of so-called "incredible" earthquakes that have begun to manifest in areas previously considered seismically safe. In their work, the scientists concluded that these anomalies are caused by human activity, which activates ancient tectonic faults that were previously in a state of "rest."
A striking example of this phenomenon is the gas field in Groningen in northern Netherlands, where natural gas has been actively extracted since the 1960s. Since the early 1990s, this previously quiet area has recorded regular earthquakes with magnitudes of up to 3.6, leading to damage to buildings. Initially, it was believed that this was related to a decrease in reservoir pressure; however, this explanation did not cover all aspects of the strong tremors in conditions that should have prevented them, as reported by AiF.
Under the guidance of Professor Ilona van Dinter, the research group established that anthropogenic earthquakes are linked to the activity of "dormant" faults. These ancient cracks, which have become solid and "healed" over time, are subjected to changes in stress in the rocks due to human activities such as mineral extraction, water injection, or carbon dioxide disposal. As a result, the "healed" faults, having lost their plasticity, begin to accumulate stress to critical levels, leading to unexpected and powerful seismic ruptures.
According to computer modeling, such seismic events are typically instantaneous. Once the accumulated energy is released, the stress in the Earth's crust stabilizes, significantly reducing the risk of recurring seismic shocks of similar strength in that area.
The results of the study have important practical implications. Firstly, they highlight a serious threat to infrastructure in traditionally stable zones that are unprepared for seismic impacts. Secondly, anthropogenic earthquakes occurring at relatively shallow depths can be quite destructive. Therefore, the scientific community and industry need to create detailed maps not only of active but also of "sleeping" faults to avoid catastrophic consequences in the future.
