Accession Number : AD0650852

Title :   A STRONG, SEASONAL BIO-ACOUSTIC SOURCE OF THE EASTERN CARIBBEAN.

Descriptive Note : Technical rept.,

Corporate Author : COLUMBIA UNIV DOBBS FERRY N Y HUDSON LABS

Personal Author(s) : Hole,Winston L.

Report Date : FEB 1967

Pagination or Media Count : 44

Abstract : Bio-acoustic pulse trains heard annually from January to March in the Lesser Antilles region and northward were studied. Pulses lasting from about 50 to 150 msec are emitted at a rate of 1 to 5 per sec for durations up to 2 min. Recordings in the frequency band to 300 Hz with bottomed hydrophones how a principal frequency in the range of either 160 to 190 Hz or 260 to 300 Hz at low or high repetition rates, respectively, and a peak power in the order of 40 to 150 W. Arrival time differences at a grid of four hydrophones have been used with a computer program to calculate source locations and, with certain assumptions, their kinematics. Of 37 locations so calculated, about half are at the surface and the rest at depths to 6600 ft. Mean speeds between locations of successive recordings are mostly in the range 1 plus or minus 0.5 knot. The identity of the source is unknown, but is a question of continuing interest. Analysis of these acoustic data suggests a balaenopterid whale as the most likely possiblity. (Author)

Descriptors :   (*UNDERWATER SOUND SIGNALS, SOURCES), MARINE BIOLOGICAL NOISE, CETACEA, ACOUSTICS, CARIBBEAN SEA, PERIODIC VARIATIONS, SUPERLOW FREQUENCY

Subject Categories : Biological Oceanography
      Acoustics

Distribution Statement : APPROVED FOR PUBLIC RELEASE