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There Are 1600-Foot-Tall Waves Under the Ocean

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Deep underneath the ocean, there are swells that would put big wave surfers to shame. The biggest waves on Earth can’t be seen breaking against the shore, but underwater, they can reach heights almost as high as the tallest building in the Western Hemisphere, and can be observed throughout the year. 

Generated by tides pulling water across the varied topography of the ocean floor, as well as wind blowing across the water's surface, the largest documented waves in the world are in the eastern border of the South China Sea, which separates China and Vietnam from the Philippines. These underwater waves can reach heights of up to 500 meters (1640 feet). Unlike surface waves that crash over a period of seconds, they last for hours, growing larger as they move across the sea floor. 

As part of a new study published in Nature, a team of scientists dropped mooring lines with measuring instruments from buoys on the surface down to the ocean floor, observing the physics at play underwater. 

These massive underwater waves move marine life across the sea, allowing creatures to surf the tide into shore to feed or breed, a key activity in maintaining the South China Sea’s coral reef system. The mixing also serves to distribute heat from the surface of the water to the depths of the ocean. 

“It’s like a giant washing machine,” Thomas Peacock of MIT, one of the paper’s co-authors, said in a press statement. “The mixing is much more dramatic than we ever expected.”

[h/t: slashdot]

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Air Quality in American National Parks and Big Cities Is Roughly the Same
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National parks usually have more vegetation, wildlife, and open spaces than urban areas, but the two don't look much different when it comes to air quality. As City Lab reports, a new study published in Science Advances found that U.S. national parks and the nation's largest cities have comparable ozone levels.

For their research, scientists from Iowa State University and Cornell University looked at air pollution data collected over 24 years from 33 national parks and the 20 most populous metro areas in the U.S. Their results show that average ozone concentrations were "statistically indistinguishable" between the two groups from 1990 to 2014.

On their own, the statistics look grim for America's protected areas, but they're actually a sign that environmental protection measures are working. Prior to the 1990s, major cities had higher ozone concentrations than national parks. At the start of the decade, the federal government passed the Clean Air Act (CAA) Amendments in an effort to fight urban air pollution, and ozone levels have been declining ever since.

The average ozone in national parks did increase in the 1990s, but then in 1999 the EPA enacted the Regional Haze Rule, which specifically aims to improve air quality and visibility in national parks. Ozone levels in national parks are now back to the levels they were at in 1990.

Ground-level ozone doesn't just make America's national parks harder to see: It can also damage plants and make it difficult for human visitors to breathe. Vehicles, especially gas-guzzling trucks and SUVs, are some of the biggest producers of the pollutant.

[h/t City Lab]

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Mark Ralston, AFP/Getty Images
How a Hairdresser Found a Way to Fight Oil Spills With Hair Clippings
Mark Ralston, AFP/Getty Images
Mark Ralston, AFP/Getty Images

The Exxon Valdez oil tanker made global news in 1989 when it dumped millions of gallons of crude oil into the waters off Alaska's coast. As experts were figuring out the best ways to handle the ecological disaster, a hairdresser from Alabama named Phil McCroy was tinkering with ideas of his own. His solution, a stocking stuffed with hair clippings, was an early version of a clean-up method that's used at real oil spill sites today, according to Vox.

Hair booms are sock-like tubes stuffed with recycled hair, fur, and wool clippings. Hair naturally soaks up oil; most of the time it's sebum, an oil secreted from our sebaceous glands, but it will attract crude oil as well. When hair booms are dragged through waters slicked with oil, they sop up all of that pollution in a way that's gentle on the environment.

The same properties that make hair a great clean-up tool at spills are also what make animals vulnerable. Marine life that depends on clean fur to stay warm can die if their coats are stained with oil that's hard to wash off. Footage of an otter covered in oil was actually what inspired Phil McCroy to come up with his hair-based invention.

Check out the full story from Vox in the video below.

[h/t Vox]

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