Earthquakes induced by hydraulic fracturing are typically believed to be caused by elevated pore pressure or increased shear stress. However, according to a recent study, these mechanisms are incompatible with experiments and rate-state frictional models that predict stable sliding (aseismic slip) for faults with high clay content or total organic carbon, as well as observations of the timings and locations of the seismicity. An alternative model was therefore proposed, in which distal, unstable regions of a fault are loaded by aseismic slip on stable regions of the fault stimulated by hydraulic fracturing. This model has significant implications in terms of mitigating induced seismicity, as it suggests that there may be a potentially measurable deformation signal tens of hours before earthquake nucleation. However, the conclusions of that study were based on a relatively small number of events from a small local broadband network. In this study we integrate a high-resolution microseismic dataset from the same treatment with that previous work, and demonstrate that the microseismic data provides an even more compelling case that aseismic slip plays a role in induced seismicity.
Presentation Date: Monday, October 12, 2020
Session Start Time: 1:50 PM
Presentation Time: 2:15 PM
Location: 360A
Presentation Type: Oral
