%0 Journal Article
%@ 2169-9313
%A Minetto, Riccardo
%A Lengline, Olivier
%A Schmittbuhl, Jean
%D 2025
%F epos:2502
%I John Wiley & Sons
%J Journal of Geophysical Research: Solid Earth
%N 12
%T B-Value Evolution During the Strasbourg 2018–2022 Sequence of Induced Earthquakes
%U https://episodesplatform.eu/eprints/2502/
%V 130
%X The b-value, defined as the slope of the cumulative earthquake frequency–magnitude distribution in semi-logarithmic space, quantifies the relative occurrence of small and large earthquakes. It is a key metric for hazard assessment and is often used in adaptive traffic light systems to mitigate induced seismicity. In this study, we analyze a 4-year sequence of induced earthquakes at the Vendenheim geothermal site near Strasbourg (France), where multiple sequential operations were carried out near a regional fault zone, to explore the spatio-temporal variability of the b-value during fault activity. Our analysis highlights the importance of spatial clustering in understanding b-value variability. Despite occurring in close spatial and temporal proximity, seismicity clusters exhibit markedly different b-values. The clusters with the lowest b-values host the largest magnitude events (  ). Even when significant seismic migration is observed within the clusters, their b-value remains relatively constant over time. The observed temporal fluctuations in the b-value of the entire induced seismicity population are shown to be closely related to the relative activity of each cluster over time. We propose that b-value variations, along with the observed seismicity migration, are related to inherited spatial variability in the geomechanical properties of faults rather than to the dynamic evolution of stress conditions.