Evolution of Short‐Term Seismic Hazard in Alberta, Canada, From Induced and Natural Earthquakes: 2011–2020

Abstract

We generate short‐term seismic hazard maps for the province of Alberta, Canada, from 2011 through 2020. First, we describe the required adaptations to probabilistic seismic hazard analysis to generate short‐term seismic hazard maps, following the Monte Carlo simulation approach. Second, we identify the natural and induced seismic source areas in Alberta and estimate their earthquake recurrence parameters revealing considerable spatio‐temporal variations in the a $a$‐ and b $b$‐values in the different seismic clusters in the province. Areas with the highest short‐term seismic hazard during the last decade in Alberta are related to cases of induced seismicity, including hydraulic fracturing activities in the Duvernay Fm., near Fox Creek, and waste‐water disposal activities near the Musreau Lake. These maps provide a valuable tool to quantify the short‐term evolution in the seismic hazard, which is particularly important considering past and emerging cases of induced seismicity related to the energy sector in Alberta. Furthermore, using parameters from the previous year, we make a seismic hazard forecast for the year 2021. Our analysis provides a baseline of expected short‐term seismic hazard, with inheren uncertainty due to the assumption of unchanged recurrence parameters from the previous year; yet our study reveals pertinent seismicity patterns in line with changing human activities.

On the Potential Role of Viscoelasticity in Fluid‐Induced Seismicity

“…The R-test focuses on interevent times (Goebel et al, 2023;van der Elst & Brodsky, 2010) and allows us to distinguish between temporal clustering typically associated with aftershock triggering and anticlustering due to the time directionality of the method (Davidsen et al, 2021). The event-event triggering analysis method is a declustering approach to distinguish between background events and aftershocks (Baiesi & Paczuski, 2004;Karimi & Davidsen, 2021, 2023Zaliapin et al, 2008) that does not use arbitrary rules (e.g., strict space-time aftershock windows) and many parameters as other methods (Davis & Frohlich, 1991;Gardner & Knopoff, 1974;Reasenberg, 1985;Reyes Canales et al, 2022) do. Figure 6 shows the outcome of the R-test using different conditions.…”