Short-term forecasting of M(max) during hydraulic fracturing.

Previous studies of injection-induced earthquake sequences have shown that the maximum magnitude (Mmax) of injection-induced seismicity increases with the net injected volume (V); however, different proposed seismic-hazard paradigms predict significantly different values of Mmax. Using injection and seismicity data from two project areas in northeastern British Columbia, Canada, where hydraulic fracturing induced seismicity was observed, we test the predictive power and robustness of three existing and one novel method to estimate Mmax. Due to their vastly different values of seismogenic index (Σ), these two project areas represent end-member cases of seismogenic response. Our novel method progressively adjusts the Mmax forecast under the assumption that each recorded event embodies an incremental release of fluid-induced stress. The results indicate that our method typically provides the lowest upper bound of the tested methods and it is less sensitive to site-specific calibration parameters such as Σ. This makes the novel method appealing for operational earthquake forecasting schemes as a real-time mitigation strategy to manage the risks of induced seismicity.

先前对注水诱发地震序列的研究表明，注水诱发地震活动的最大震级（Mmax）随净注水量（V）增加；然而，不同的地震灾害范式所预测的Mmax值差异显著。利用加拿大不列颠哥伦比亚省东北部两个项目区的注水和地震活动数据（在这些地区观察到了水力压裂诱发的地震活动），我们测试了三种现有方法和一种新方法对Mmax估计的预测能力和稳健性。由于这两个项目区的孕震指数（Σ）值差异很大，它们代表了孕震响应的极端情况。我们的新方法在假设每次记录到的事件都体现了流体诱发应力的增量释放的情况下，逐步调整Mmax预测值。结果表明，我们的方法通常提供了所测试方法中最低的上限，并且对诸如Σ等特定场地的校准参数不太敏感。这使得新方法作为一种管理诱发地震活动风险的实时减灾策略，对地震作业预报方案具有吸引力。