Seismic hazard estimates for the Cascadia Subduction Zone (CSZ) rely on shaking proxies such as offshore turbidites that can be used derive to magnitude and recurrence intervals. These assume that shaking from CSZ earthquakes remobilizes seafloor sediment, but empirical observations of seismically-generated turbidity currents are lacking in the CSZ. Few quantitative estimates exist linking shaking intensity to turbidity current generation, challenging our ability to fully constrain past shaking and earthquake characteristics. The Ocean Networks Canada (ONC) cabled seafloor array in Barkley Canyon provides concurrent seismic, turbidity, and other oceanographic data in a seismically active portion of the margin. Multiple large regional (>M6) and moderate local (<M6) earthquakes occurred during the ONC operating period 2016-2023, allowing us to search for direct observations of shaking and concurrent canyon system processes. 

Using the Barkley Canyon Axis (BACAX) oceanographic nearbed turbidity sensor data, we created a catalog of turbidity events at BACAX using a short-term average/long-term average (STA/LTA) algorithm to identify elevated signal levels with a subsequent exponential decay. To determine the likely cause, we examined associated oceanographic data (i.e., oxygen, temperature), and acoustic doppler current profiler (ADCP) velocities. We also computed shaking intensity from regional seismicity and theoretical strain measurements generated by large regional and teleseismic events. We evaluated correlations between the turbidity events and associated metadata. We found nearly all 50 events at BACAX are internal tide generated, and unrelated to shaking, except one down-canyon event that is not preceded by significant shaking or strain. We conclude that there were no statistically significant links between ground motions and turbidity events at this site. This method may be used at other canyon systems, where sediment transport processes may differ from the sediment-starved Barkley Canyon.

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