Locations of the three instruments deployed at 300 m depth in the Davis Strait. The monthly extension of the sea ice edge from November 2006 to March 2007 is shown as lines in the inset map.
(A) Time series and spectrogram of fin whale song with clearly separated calls consisting of high frequency (HF) and low frequency (LF) components. The pulses are recorded on top of a band of fin whale songs in the background. (B) Example of a band of LF fin whale signals too closely spaced in time to identify single pulses. FFT size: 2048, 50% overlap, window: 512.
Spectrogram, waveform and power spectrum of the time aligned average of 50 typical fin whale calls, showing the low frequency down-sweep (LF) and the secondary, lower amplitude high frequency pulse (HF). FFT size: 1024, 94% overlap, Hann window.
Power analysis showing the seasonal output of the power in the fin whale frequency band, (blue) and the surrounding noise bands, (red). The power in both are bands expressed relative the yearly grand average of the background noise power.
Dynamics of normalized power in the fin whale (upper panel) and noise (lower panel) frequency bands and the distance to the ice edge (upper panel, broken lines) when the sea ice edge has covered the mooring. The distance was set to zero when the sea ice edge was north of the mooring. All data was computed as the mean of 5 days.
Diel variation in the power of the (upper panel) and frequency band (lower panel). The -axis shows the days from 12 November to 22 December. The -axis shows the time of the day in hours. The image displays show the relative intensity in the frequency bands with increasing intensities illustrated by blue to red color scale. There is a clear diel pattern with the whales singing most of the day with a clear decrease in singing activity a few hours in the middle of the day.
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