The Shallow Water Canada Basin Acoustic Propagation Experiment was conducted on the Chukchi Sea continental shelf from October 2016 to November 2017. The experimental goals were to access (1) long-range (basin-scale) and (2) short-range (shallow-water) spatial and temporal energy variation. This letter focuses on a 20-dB energy change of acoustic signals in the frequency band 700-1100?Hz from June to August 2017 occurring along two shallow-water tracks from a common source, correlated with the occurrence of an oceanographic event in the top 150-m water column due to a Pacific Water outflow from the Bering Sea and retreat of the Marginal Ice Zone.