SAN FRANCISCO — A PLAN to transmit waves of noise through loudspeakers placed on the Pacific Ocean bed is causing concern among some scientists who fear the sound could deafen whales and other rare marine mammals.
The $35 million plan, led by scientists at the University of California at San Diego's Scripps Institution of Oceanography, is aimed at testing whether the ocean temperature is rising because of global warming.
Under the initial two-year phase of the plan, one loudspeaker would be placed on the ocean bed off Point Sur in northern California and another off Hawaii - both important habitats for whales and seals. The California loudspeaker would be in the Monterey Bay National Marine Sanctuary and on the migration route of the humpback whale.
Loud, low-pitched noises, likened by project scientists to ``someone scratching on a drum,'' would be broadcast for 20 minutes every four hours.
The noises would travel for thousands of miles along the ocean's deep sound channel and be picked up by United States Navy listening devices. Scientists believe they will be able to detect temperature changes in the ocean by measuring how fast the noise travels.