Induced seismicity at the Quest Carbon Capture and Storage project, Alberta

The 1st April and 9th May 2026 M L ≥ 4.0 earthquakes in central Alberta were felt across the city of Edmonton. The events were located near to Carbon Capture and Storage (CCS) operations at the Quest site. In this study we use an established induced seismicity assessment framework, applied with respect to the Quest CCS site as well as other oilfield activities in the area, to assess whether the events were induced. We found that these earthquakes were likely caused by CO 2 injection at Quest, making this the first known example of felt induced seismicity caused by CCS operations. We have inverted regional seismic monitoring data to compute event depths and source mechanisms, finding that the events were located in the upper portion of crystalline basement, with oblique strike-slip/reverse focal mechanisms. We apply several induced seismicity magnitude forecasting schemes to the earthquake sequence in order to evaluate whether the seismic hazard posed by these events could have been identified. We found that two models – the seismogenic index model and a model based on extreme value theory – would both have forecasted the M L 4.0 events prior to their occurrence. These results demonstrate that induced event forecasting methods can be used to support operational decision-making. We conclude by considering options for ongoing induced seismicity hazard mitigation, both at the Quest CCS site, and more generally at any future CCS operations.