Recent research sheds light on an intriguing phenomenon: the occurrence of earthquakes in regions previously deemed tectonically inactive. Our Dr. Ylona van Dinther provided new insight to this field through a pioneering study published in Nature Communications. It shows otherwise, that induced earthquakes can happen on dormant faults that have been stable for millions of years. This discovery turns conventional thinking about seismic activity on its head and raises exciting new implications for how we understand Earth’s geological processes.
Dr. Ylona van Dinther, a prominent researcher in her field, oversaw the project. It underscores the ways that seismicity can surprise us by striking in places thought to have no active fault movements. The multi-institution research team, with lead scientist Meng Li, analyzed how fault-slip behavior develops. Human activity and stress on the network. This panel centered on how human activities have stressed the network in the Earth’s crust.
Induced Earthquakes on Dormant Faults
Induced earthquakes usually occur on faults. These tectonic faults have been “overdue” for years or decades, having been suppressed in the states of tectonic homeostasis across multiple tectonic cycles. Most of these faults are located in the upper crust, where subsurface stability is usually taken for granted. As Dr. van Dinther made clear, “faults are just about everywhere. Faults in the shallow subsurface tend to be stable, thus, we don’t predict shock displacements along these types of features.
Over the course of millions of years, this inactivity can cause stress to accumulate along these otherwise dormant faults. As this built-up stress passes a certain point, the strain is released in a sudden burst of energy—an earthquake, in other words. Ebert and colleagues’ research indicates that geological processes continue to be active under the surface, even in the most geologically quiet areas. This has the potential to induce unforeseen earthquakes.
Implications of the Research Findings
These results from Dr. van Dinther’s group have serious implications for the scientific knowledge and for real-world applications. Given that many earthquakes occur without prior warning, understanding the mechanisms behind induced seismicity is crucial for risk assessment and management.
Dr. van Dinther emphasized the long-term effects of human activities on subsurface stability: “This means that, although the subsurface in such areas will not settle immediately after human operations stop, the strength of the earthquakes—including the maximum expected magnitude—will gradually decrease.” This insight suggests that while immediate seismic risks may persist temporarily after human intervention ceases, they are likely to diminish over time.
The new research also introduces the Human-Induced Earthquake Database (HiQuake). Holding and triggering the tectonic earthquake This database catalogs induced earthquakes of various types, particularly those triggered by subsurface injection and extraction activities. Researchers warn that this catalog is far from complete. They call for continued monitoring, study and mitigation of human-induced seismicity.
Understanding Seismic Activity Through Data
To add some additional color to these findings, researchers delved deep into the U.S. Geological Survey (USGS) catalog. This catalog is a record of natural earthquakes with moment magnitude over five. The USGS catalog from 2021, with shading to show hypocenter depth. This design allows us to learn important lessons about the distribution and occurrence of seismic events across a range of geological settings.
Merging datasets from HiQuake and the USGS provides us with unprecedented and powerful insights. We are learning more about when and where earthquakes may occur, even in regions once thought safe. The interaction between natural geologic processes and anthropogenic activities is still a key area for future research.