Researchers at the German Research Center for Geosciences have identified that the roughness of pre-existing faults and the resulting stress heterogeneity within geological reservoirs significantly influence the occurrence of man-made earthquakes. The study’s insights were published in a prominent science journal.
The work combines experimental results from acoustically monitored fluid injection into faults with a geomechanical laboratory study that simulated how injected fluid interacts with geological reservoirs.
During the laboratory tests, scientists observed that rough and smooth fractures in rocks respond very differently. This finding is notable because it reveals a progressive localization of microseismic activity, signaling stress transfer during fluid injection.
Compared with smooth faults, slip on rough faults tends to create spatially localized clusters of acoustic emissions around high-stress asperities. In these regions, the frequency of local slips rises, followed by a larger number of earthquakes in the surrounding area.
The team plans to expand the investigation to uncover the factors that contribute to anthropogenic earthquakes. The overarching aim is to understand how such events can be better controlled or mitigated to reduce seismic risk.
These findings contribute to the broader effort to explain how human activities influence seismic patterns and what precautions may be taken to minimize hazardous outcomes in subsurface operations.