Fig. 8From: A test of the detection range of acoustic transmitters and receivers deployed in deep waters of Southeast Alaska, USAPeriodograms computed via Fast Fourier transform of hourly total acoustic transmitter detections at an acoustic range-testing station located within a narrow inshore passage (Station 4; left panels) and at a station on the exposed continental shelf (Station 5; right panels). a Receptions from transmitters suspended 5.0 m off bottom at Station 4; b receptions from transmitters suspended 0.5 m off bottom at Station 4; c receptions from transmitters suspended 5.0 m off bottom at Station 5; and d receptions from transmitters suspended 0.5 m off bottom at Station 5. Periodic cycles in tag detection are apparent at period lengths of 24, 12.6, 8, and ~6 hours; note that the cycles with diurnal (24-hour) and 8-hr periodicity ceased during mid-winterBack to article page