Automated Detection of Dynamic Earthquake Triggering by the High‐frequency Power Integral Ratio

Dynamic earthquake triggering can be used to investigate the responses of faults to stress disturbances. We develop a new method to detect dynamic triggering by estimating high-frequency energy change before and during teleseismic waves using the HIgh-Frequency power Integral ratio (HiFi). Our method is able to identify local events independent of earthquake catalog or subjective judgements. The significance in energy change is evaluated by a statistical analysis of the background ratio in a large number of days, which can suppress the influence of noise and variations in the background seismicity and yield a confidence level of dynamic triggering (0-1). We apply the HiFi method to the Geysers Geothermal Field in California, and the results are largely consistent with previous reports from the beta statistic. By comparing the results of HiFi and beta statistic, we select a confidence level range of 0.918-0.947 as the optimum threshold to identify dynamic triggering in the region.