Figure 6
From: Marine mammal acoustic detections in the Greenland and Barents Sea, 2013 – 2014 seasons
Spectrogram of unknown tonal signals in a sequence of about 2 min (Timescale 110 s, frequency scale 10–650 Hz). The signals are short, frequency modulated down- and upsweep signals occurring in a sequence that starts at about 400–600 Hz and ends around 50 Hz. There is a clear alternating pattern between low and higher frequency units5 (Similar signals were detected on several days at the end of October (e.g.104,105,106,107).
