Fig. 2: Median one-third octave bands centered at 63 and 125 Hz recorded during 2018–2022 at Ocean Station Papa.
From: North Pacific Ocean sound levels 2018–2022: COVID-19 pandemic impacts on anthropogenic noise
Two-week running average sound levels for each calendar year are visualized as smoothed solid colored lines overlaid on semi-transparent points that represent daily median sound levels. Breaks in the solid colored lines indicate gaps in the recording. Each of these northeast Pacific hydrophone sites shows a 1–3 dB reduction in sound levels during Spring and Summer 2020, which represents a substantial 20–30% decline during early 2020, consistent with reduced ship traffic levels.
