As carbon dioxide continues to build up in Earth’s atmosphere, it will also accumulate in her oceans. This rise in CO2 has already made the upper ocean more acidic and the same is expected to happen even in the lower depths in the coming century.
Physicists from the Woods Hole Oceanographic Institution now say that these changes will make some far flung reaches of the ocean more noisy. In a paper published last week in the Journal of the Acoustical Society of America, the team modeled ambient shipping noise for the deep ocean, incorporating forecasts for ocean pH levels and shipping noise in the coming century.
Any first year physics student knows the thickness of a fluid is important in considering how well sound waves propagate, but also of crucial importance in sea water is the concentration of boric acid and other chemicals. Boron ions help filter out low frequency waves, but as the ocean gets increasingly acidic, the amount of boron ions will decrease and these low frequency sound waves will penetrate into deeper waters.
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Flash Modin, physics central, Buzz Blog, 24 August 2010. Full article.
