Spectrogram (left) of a Northeast Pacific blue whale call. Northeastern Pacific blue whale calls are perhaps the best known blue whale call to date. They generally consist of two parts, A and B. The A call is a series of pulses (on the order of 1.5 pulses/s) which often exhibits side-banding, while the B call is a long FM moan. These calls have been recorded from offshore Vancouver Island B.C., Washington, Oregon, California and off Mexico in the Gulf of California and in the Eastern Tropical Pacific. Picture (right) of a blue whale. Image courtesy of Submarine Ring of Fire 2002, NOAA/OER.
