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Kauai underwater
By Anthony Sommer
sound tests facing
public hearings
Star-BulletinLIHUE -- The first in a series of public hearings on a proposal to continue low frequency underwater transmissions from Kauai to the mainland drew a small crowd and not a single word of protest at Kauai Community College last night.
Several local environmentalists attended but, although they had questions about the program's effects on humpback whales, they did not speak against continuation of the program.
Originally called ATOC -- Acoustic Thermometry of Ocean Climate -- the revived version has been renamed NPALS -- North Pacific Acoustic Laboratory -- but it is otherwise unchanged.
Using a transmitter on the sea floor just offshore of Kauai, low frequency sound is sent to receivers along the Pacific coast -- most of them installed during the Cold War by the Navy to listen for Soviet submarines. The length of time it takes to receive the signal is recorded. Because sound travels through water at different speeds depending upon temperature, the average temperature of the water between the transmitter and receivers can be computed.
The method has achieved levels of accuracy well beyond the hopes of its designers. It can detect temperature shifts as small as one hundredth of a degree centigrade.
An identical transmitter is located on the California coast and beams sound to receivers across the central Pacific.
The sound waves travel more than 3,000 miles.
Environmentalists have been concerned about the effect of the transmissions on whales.
However, observations during the 19 months ATOC was active off Kauai in 1998 and 1999 showed only slight differences in the length of time and frequency of dive made by humpback whales, compared to observations made before the testing began.
There were no other changes in behaviors of the humpback whales to indicate they were being disturbed by the sounds.
The project is being sponsored by the Navy, and that has led many of the same environmental groups that have gone to court to shut down long-range sonar testing off the Big Island to criticize ATOC.
But ATOC officials said their transmissions are in a totally different range of the sound spectrum and at a much lower power than the sonar equipment -- 260 watts for ATOC compared to 26,000 watts for the sonar.
Peter Wocester of Scripps Institution of Oceanography said the tests have allowed scientists to begin to collect information about the underwater "climate" of the north Pacific.
The ocean has weather just like the atmosphere, but little is known about its long-term trends.
The project is seeking state permits to continue testing.
Last night's hearing was a part of the environmental impact statement approval process.
Another hearing is scheduled tonight at 7 p.m. at the Hawaii Imin International Conference Center on the second floor of the East-West Center and in Kilauea, Kauai, on Saturday at 1:30 p.m. at the Kilauea Neighborhood Center.
A copy of the draft environmental impact statement is available online at http://npal.ucsd.edu.
