Ground motions in Yukon from the Tatshenshini-Alsek Park earthquakes of 2017 compared to 2015 Canadian seismic design levels

Two magnitude 6 earthquakes in the Tatshenshini-Alsek Park on May 1, 2017, produced ground motions that exceeded 5% to 22% of the 2015 Canadian seismic design levels, with Haines Junction experiencing up to 7.5% and Whitehorse up to 22%. Despite the second earthquake being larger in magnitude, the first event generated stronger spectral accelerations near Haines Junction, reaching approximately 3% at 0.2 seconds. These findings highlight significant variability in seismic hazards, even within the same region, and underscore the importance of localized site conditions in amplifying or reducing ground motion values.

Kolaj, M. (2018). Ground motions in Yukon from the Tatshenshini-Alsek Park earthquakes of 2017 compared to 2015 Canadian seismic design levels (, Ed.). Natural Resources Canada/CMSS/Information Management. https://doi.org/10.4095/306502