The 20-Hz signals of finback whales (Balaenoptera physalus) were analyzed from more than 25 years of recordings at a variety of geographic locations on near-surface hydrophones close to whales and on deep hydrophone systems. These signals were composed of 1-sec pulses of sinusoidal waveform with downward sweeping frequency from approximately 23 to 18 Hz at variable levels up to 186 dB (re 1 uPa), usually with slightly lower levels for ...
Reports by Author
