eprintid: 2502 rev_number: 12 eprint_status: archive userid: 6 dir: disk0/00/00/25/02 datestamp: 2026-01-29 10:31:12 lastmod: 2026-01-29 11:08:18 status_changed: 2026-01-29 10:31:12 type: article metadata_visibility: show creators_name: Minetto, Riccardo creators_name: Lengline, Olivier creators_name: Schmittbuhl, Jean title: B-Value Evolution During the Strasbourg 2018–2022 Sequence of Induced Earthquakes subjects: RF6 subjects: SG divisions: GEO5 full_text_status: none abstract: 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. date: 2025-12 date_type: published publication: Journal of Geophysical Research: Solid Earth volume: 130 number: 12 publisher: John Wiley & Sons id_number: https://doi.org/10.1029/2025JB031744 issn: 2169-9313 official_url: https://agupubs.onlinelibrary.wiley.com/doi/10.1029/2025JB031744 access_IS-EPOS: limited owner: Publisher citation: Minetto, Riccardo and Lengline, Olivier and Schmittbuhl, Jean (2025) B-Value Evolution During the Strasbourg 2018–2022 Sequence of Induced Earthquakes. Journal of Geophysical Research: Solid Earth, 130 (12). DOI: https://doi.org/10.1029/2025JB031744