Tag Archives: Pacific Marine Environmental Laboratory

Amusing Monday: Mysterious ocean sounds are not always ‘creepy’

Some underwater ocean sounds remain a mystery, while other sounds are well understood by NOAA’s Pacific Marine Environmental Laboratory.

PMEL’s acoustic division continues to find unusual sounds within its long-term mission of recording and measuring ocean noise and assessing potential problems created by noisy humans.

Sounds ranging from whale calls and volcanoes to cargo ships and airguns are monitored by the Pacific Marine Environmental Laboratory with the help of 11 Ocean Noise Reference Stations from Alaska to the South Pacific. Graphic: NOAA's Pacific Marine Environmental Laboratory
Sounds ranging from whale calls and volcanoes to cargo ships and airguns are monitored by the Pacific Marine Environmental Laboratory with the help of 11 Ocean Noise Reference Stations.
Graphic: NOAA’s Pacific Marine Environmental Laboratory

I remain intrigued by ocean sounds, and I can’t help but worry about sensitive marine creatures, such as whales, that must live in our modern world of noisy ships and machinery.

One mysterious sound nicknamed “Upsweep” was present when PMEL began recording on the Navy’s SOSUS (Sound Surveillance System) array in August 1991. The sound, which consists of a series of upsweeping sounds, is loud enough to be heard throughout the Pacific Ocean, according to PMEL’s website. This sound was speeded up 20 times to be more easily heard.

      1. Upsweep-PMEL

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Study shows increasing acidity in Northeast Pacific

For those of us concerned about sealife, the issue of ocean acidification is beginning to be at least as worrisome as rising ocean temperatures.

The first direct evidence of ocean acidification across a broad expanse of ocean was revealed this week in a new report detailing an ongoing study focused on waters between Hawaii and Alaska.

Ocean acidification, related to the buildup of carbon dioxide in the atmosphere, is believed to be affecting the ocean’s food web, beginning with creatures that form external shells of calcium and carbonate.

A new report, based on direct measurements of acidity at the ocean’s surface, as well as biological changes down to half a mile, show an increase in acid concentrations. Principal investigator Robert Byrne of the University of South Florida said there is no longer any doubt that increasing levels of CO2 in the atmosphere are affecting the world’s oceans.

“If this happens in a piece of ocean as big as a whole ocean basin, then this is a global phenomenon,” Byrne said in a news release.

Scientists from 11 academic institutions and two labs operated by the National Oceanic and Atmospheric Administration are taking part in a long-term study of ocean conditions in the Northeast Pacific Ocean, where changes are happening rapidly.

Christopher Sabine, one of the leaders of the investigation, commented in the news release:

“It is now established from models that there is a strong possibility that dissolved carbon dioxide in the ocean surface will double over its pre-industrial value by the middle of this century, with accompanying surface ocean pH decreases that are greater than those experienced during the transition from ice ages to warm ages. The uptake of anthropogenic carbon dioxide by the ocean changes the chemistry of the oceans and can potentially have significant impacts on the biological systems in the upper oceans.”

We have talked before in Water Ways about ocean acidification, but in a more speculative way. More information is coming out all the time. An excellent synthesis of current knowledge can be found in the latest issue of the journal “Oceanography.” Although somewhat technical, the subject is broken down into focused articles that are easy to get through. I recommend that anyone who cares about the oceans spend a little time with this online information.

For a more general description, check out the Pacific Marine Environmental Laboratory’s page on Ocean Acidification including a brief fact sheet (PDF 280 kb) on the topic.

Sandi Daughton, science reporter for the Seattle Times, wrote about the latest findings in a story on Wednesday.