Statistical bounds on how induced seismicity stops

Abstract

Earthquakes caused by human activities receive scrutiny due to the risks and hazards they pose. Seismicity that occurs after the causative anthropogenic operation stops has been particularly problematic—both because of high-profile cases of damage caused by this trailing seismicity and due to the loss of control for risk management. With this motivation, we undertake a statistical examination of how induced seismicity stops. We borrow the concept of Båth’s law from tectonic aftershock sequences. Båth’s law anticipates the difference between magnitudes in two subsets of seismicity as dependent on their population count ratio. We test this concept for its applicability to induced seismicity, including ~ 80 cases of earthquakes caused by hydraulic fracturing, enhanced geothermal systems, and other fluid-injections with clear operational end points. We find that induced seismicity obeys Båth’s law: both in terms of the magnitude-count-ratio relationship and the power law distribution of residuals. Furthermore, the distribution of count ratios is skewed and heavy-tailed, with most earthquakes occurring during stimulation/injection. We discuss potential models to improve the characterization of these count ratios and propose a Seismogenic Fault Injection Test to measure their parameters in situ. We conclude that Båth’s law quantifies the occurrence of earthquake magnitudes trailing anthropogenic operations.

Modelling of fluid pressure migration in a pressure sensitive fault zone subject to cyclic injection and implications for injection-induced seismicity

“…post shut-in events or events during low injection rate) to be able to react before another high-rate injection phase is started and introduced into the system (Hofmann et al 2018). Therefore, our results may also confirm the feasibility of the diagnostic Seismogenic Fault Injection Tests (SFIT) using repeated injection proposed by Schultz et al (2022) to constrain the fault's seismogenic parameters in their statistical models for post shut-in seismicity. However, the diagnostic repeated injection in SFIT should be different from the simplified sine-wave cyclic injection in our models.…”

“…However, the diagnostic repeated injection in SFIT should be different from the simplified sine-wave cyclic injection in our models. As has already been pointed out by Schultz et al (2022), the injection in SFIT should be designed with non-periodic intervals and different injection and shut-in rates to better discern any time-dependent and rate-dependent features of post shut-in seismicity. This can be considered in future modelling studies.…”

Pseudo‐Prospective Forecasting of Induced and Natural Seismicity in the Hengill Geothermal Field

“…Another important aspect of induced seismicity mitigation methods relies on linking modeling results to hazard and risk calculations (Broccardo et al, 2019;Schultz et al, 2021Schultz et al, , 2022. In this work, we stopped on the level of forecasting seismicity rates and did not venture further, however, we do plan to expand to hazard and risk in future work.…”

Stress Transfer Outpaces Injection-Induced Aseismic Slip and Triggers Seismicity

“…Given the difficulty of knowing the stress condition on the fault before injection operations, it would be advisable to control the injection rate to have a better control over induced seismicity [28][29][30][31][32][33] . Additionally, in-situ tests such as the Seismogenic Fault Injection Test (SFIT) have been proposed to calibrate the seismic response to fluid injection of known faults, so as to better understand the risk associated with seismicity trailing an anthropogenic operation 34 .…”