| Abstrakt: |
Recordings of man-made underwater noise in the Barrow and Prudhoe areas provided acoustic measurements of helicopters, cranes, detonations, power plants, island building, seismic profiling, off-shore drilling, human movements, unidentified machinery, tugs, and other marine service craft. The recordings, made in winter, spring, and fall, were obtained from under the ice, or from leads, polynyas, or open water at distances from a few meters to about 185 km from the source. Estimated overall source levels varied from 40 to over 200 dB re 1 μPa at 1 m, in the effective bandwidths. Principal acoustic energy occurred in bands falling between 10 Hz and 13 kHz. Among the lowest levels encountered were those from the sounds of oil exploration drilling. The highest were from seismic profiling. Durations of man-made sounds varied from msec (metallic impulses) to continuous (line spectra from engines). In terms of frequency (Hz), duration, and power, many of the measured man-made sounds had the potential for masking underwater animal vocalizations or other acoustic signals. Speculations are made on the possibility of inducing avoidance or even deafness. [Work supported by AEWC, NOAA/OCSEAP.] [ABSTRACT FROM AUTHOR] |
