A proposal to use underwater sound waves to study global warming is on hold while it is determined whether the noise will disturb sea life.
The research project had been assailed by environmental groups and others who believed the 195-decibel sound blasts would hurt animals that need to hear to survive, such as dolphins and whales.
"We're just trying to get this thing settled," said Walter Munk, a Scripps Institution of Oceanography physicist in charge of the experiment. "The disadvantage now is that we lost time. The advantage is that, hopefully, it will lead to an agreement that is acceptable."
The decision for further study was announced Saturday as the research team readied for a public hearing here on its request for a permit for the experiment. The National Marine Fisheries Service ultimately will make the decision.
The $35-million experiment is being funded by the Department of Defense. Two sound transmitters would be placed in waters off Point Sur in the Monterey Bay Marine Sanctuary and off Kauai's north shore in the Hawaiian Islands.
The transmitters would emit sounds for 20 minutes every four hours to 18 receivers in the Pacific Ocean. Because sound moves faster in warmer water, evidence of global warming could be found if the sounds hit the receivers at an increasing pace.
Critics of the project cautiously praised the decision.
"It's about time they started thinking along those lines," said Vicki Nichols, executive director of Save Our Shores in Santa Cruz.