27 Dec 1973
- waterbody:North Atlantic OceanGrand Turk Island; U.S. Naval Facility
NOTES: Notes from tape: "Time 1200 Zulu 27Dec1973." [MLNS notes: first 14:23 and last 5:00 removed - high noise, no signal. 19Dec2003 CB] Notes from analysis log: "Cassette number side down - rewind. Ambient level moderate, later in hear ship traffic propeller beats twin propellers. Around 695 hear bangs, open mike room noise? door shuts. Humpback: Neg.; Minke: Pos.; No. Calling: 1? No. Trains: 3. Need for further analysis: Yes Yes. Notes: At 424 is a nice strong clear sample, long, train. Kind of real long, longest one yet heard, again at 617, good long train & sig level; Again at 660, only weaker."
[Notes from analysis log for all tapes in the GRANDTURKS series: "Six half-hour background recording samples on selected days for a period of 53 days... to detect the arrival and departure of the Humpback whales (via sounds) for the season in the Caribbean Sea, Mouchier, Navidad and Silver Banks...There are indications that recordings used a 420Hz Low Pass Filter. Recording equipment used was a Realistic model CTR-19. Cassette recorder operating on 110VAC, Freq 60-10,000Ha.. The Realistic recorder is poor recording frequencies below 60Hz as evidenced by spec sheet and sonograms. There is 120 & 180Hz electrical interference 'splatter' on some tapes. In certain cases when the ambient is low, the gain of the systems are raised hence we have heavy interference masking wanted signals. This could be caused by a fluorescent light fixture near the recording system? I doubt that it is in the hydrophone pre-amp network." See analysis log for more details.] SEAOCEAN