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Another Look at How Sound Travels In the Ocean
Next week the the Acoustical Society of America (which would be a great name for a indie rock band) will meet in Kansas City, Missouri for their 164th meeting.
David G. Browning, an acoustician, will present the findings of a study at the meeting that suggest the rise of carbon dioxide in the ocean, likely due to global warming and its affect on the ocean’s acidity, could change the way sound travels in the ocean.
"We call it the Cretaceous acoustic effect, because ocean acidification forced by global warming appears to be leading us back to the similar ocean acoustic conditions as those that existed 110 million years ago, during the Age of Dinosaurs," Browning explained in a statement this morning.
First of all how do we know what the acoustic conditions were in the ocean 110 million years ago if A) there were no humans around and certainly none that survived to tell us and B) Dinosaurs didn’t survive and definitely didn’t have the capacity to speak and again tell us what conditions were like way back when. You’d think we would just say “magic” and move on but that’s not how Browning, the lead author of the paper, came to his conclusion.
Browning and Peter Scheifele from the University of Connecticut used previous research from another study conducted by The Royal Society that analyzed historic levels of boron in seafloor sediments. The Royal Society then used the data to estimate the ocean acidification levels for the past 300 million years.
Browning used the boron's sound absorption traits and impact on low-frequency transmission to surmise that today’s oceans transmit sound similar to the way they did 300 million years ago during the Paleozoic Era. The team found transmission improved as ocean acidity rose and 110 million years ago was the best time for transmission value:low frequency sound traveled twice as far under those conditions.
"This knowledge is important in many ways,” said Browning. “It impacts the design and performance prediction of sonar systems. It affects estimation of low frequency ambient noise levels in the ocean. And it's something we have to consider to improve our understanding of the sound environment of marine mammals and the effects of human activity on that environment."
The statement noted that further work will be done to verify the model and if conditions continue SCUBA divers by the year 2100 might be able to hear sound in the ocean with the clarity that ancient marine life once did.
1944: Camano Class Light Cargo Ship was laid down for the US Army as FS-289 at Wheeler Shipbuilding in Whitestone, NY.
1955 - 1963: Used as a cargo supply ship for the Texas Towers, a network of advanced radar stations located off the Eastern Seaboard. In 1957, Capt. Sixto Mangual was commander of the AKL-17 and in 1961 it was rechristened the USNS New Bedford. The New Bedford, sailing out of State Pier, was keeping vigil when Texas Tower No. 4 callapsed off the New Jersey coast during a January 1961 nor'easter.
2006: Design of the Tesla Turbine began on June 11, 2006. The Sea Bird was sold by Defense Reutilization and Marketing Service for commercial service.