The Science Behind Antarctica's Blood Falls

In 1911, a geologist on the ultimately doomed Terra Nova expedition to the South Pole discovered a five-story-tall, blood-red waterfall in the middle of the frozen Antarctic desert lands. The area, known as the McMurdo Dry Valleys, is the largest ice-free region on the continent, and one of the coldest, driest, most Mars-like places on Earth.

The so-called Blood Falls ooze from a crack in Taylor Glacier onto the ice-covered Lake Bonney. Twice as salty as seawater, the red brine never freezes. But why is it so red? It's because of the extremely rich presence of iron in the water, which oxidizes and turns crimson when exposed to air, as a research team led by microbiologist Jill Mikucki discovered in 2009. The team also identified 17 microorganisms in the surface brine. Before then, scientists thought a type of algae might be responsible for the red hue.

Image Credit: Peter Rejcek, National Science Foundation

More recent research by Mikucki, published in Nature Communications, discovered that the source of Blood Falls is a subglacial lake. They conducted the first-ever landscape-scale survey of subsurface resistivity in Antarctica. They mapped the region using a large airborne electromagnetic (AEM) system called SkyTEM, which was flown via helicopter. As Smithsonian notes, when water freezes, it has higher electrical resistivity. Salt-rich brine, on the other hand, has low resistivity.

You can see a short video of the AEM system here:

According to New Scientist, the sensor detected a 185-meter-long lake beneath the surface near Blood Falls. Nearly devoid of oxygen and trapped a quarter-mile down for 2 million years, the lake nevertheless harbors life, which appears to use sulfate instead of oxygen for respiration. Because the researchers detected large regions of low electrical resistivity beneath the surface, they believe the lake is one of two extensive subsurface brine systems.

As Mikucki told the Washington Post, "We found, as expected, that there was something sourcing Blood Falls…and we found that these brines were more widespread than previously thought. They appear to connect these surface lakes that appear separated on the ground. That means there's the potential for a much more extensive subsurface ecosystem, which I'm pretty jazzed about."

This is one conceptualization of how the subglacial lakes may connect beneath the surface of the forbidding region:

 

 

Image Credit: J.A. Mikuckiin, in Nature Communications

Amazon's Under-the-Radar Coupon Page Features Deals on Home Goods, Electronics, and Groceries

Stock Catalog, Flickr // CC BY 2.0
Stock Catalog, Flickr // CC BY 2.0

This article contains affiliate links to products selected by our editors. Mental Floss may receive a commission for purchases made through these links.

Now that Prime Day is over, and with Black Friday and Cyber Monday still a few weeks away, online deals may seem harder to come by. And while it can be a hassle to scour the internet for promo codes, buy-one-get-one deals, and flash sales, Amazon actually has an extensive coupon page you might not know about that features deals to look through every day.

As pointed out by People, the coupon page breaks deals down by categories, like electronics, home & kitchen, and groceries (the coupons even work with SNAP benefits). Since most of the deals revolve around the essentials, it's easy to stock up on items like Cottonelle toilet paper, Tide Pods, Cascade dishwasher detergent, and a 50 pack of surgical masks whenever you're running low.

But the low prices don't just stop at necessities. If you’re looking for the best deal on headphones, all you have to do is go to the electronics coupon page and it will bring up a deal on these COWIN E7 PRO noise-canceling headphones, which are now $80, thanks to a $10 coupon you could have missed.

Alternatively, if you are looking for deals on specific brands, you can search for their coupons from the page. So if you've had your eye on the Homall S-Racer gaming chair, you’ll find there's currently a coupon that saves you 5 percent, thanks to a simple search.

To discover all the deals you have been missing out on, head over to the Amazon Coupons page.

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The Northern Lights Storms Are Getting Names—and You Can Offer Up Your Suggestions

A nameless northern lights show in Ylläs, Finland.
A nameless northern lights show in Ylläs, Finland.
Heikki Holstila, Flickr // CC BY-ND 2.0

While all northern lights are spectacular, they’re not all spectacular in the same way. Aurora borealis, or “northern dawn,” occurs when electrons in the magnetic field surrounding Earth transfer energy to oxygen and nitrogen molecules in the atmosphere. The molecules then emit the excess energy as light particles, which create scintillating displays whose colors and shapes depend on many known and unknown factors [PDF]—type of molecule, amount of energy transferred, location in the magnetosphere, etc.

Though the “storms” are extremely distinct from each other, they haven’t been named in the past the way hurricanes and other storms are christened. That’s now changing, courtesy of a tourism organization called Visit Arctic Europe. As Travel + Leisure reports, the organization will now christen the strongest storms with Nordic names to make it easier to keep track of them.

“There are so many northern lights visible in Arctic Europe from autumn to early spring that we started giving them names the same way other storms are named. This way, they get their own identities and it’s easier to communicate about them,” Visit Arctic Europe’s program director Rauno Posio explained in a statement.

Scientists will be able to reference the names in their studies, much like they do with hurricanes. And if you’re a tourist hoping to check out other people’s footage of the specific sky show you just witnessed, searching by name on social media will likely turn up better results than a broad “#auroraborealis.”

Visit Arctic Europe has already given names to recent northern lights storms, including Freya, after the Norse goddess of love, beauty, and fertility, and Sampo, after “the miracle machine and magic mill in the Finnish national epic poem, ‘Kalevala.’” A few other monikers pay tribute to some of the organization’s resident “aurora hunters.”

But you don’t have to be a goddess or an aurora hunter in order to get in on the action. Anybody can submit a name (along with an optional explanation for your suggestion) through the “Naming Auroras” page here. It’s probably safe to assume that submissions related to Nordic history or culture have a better chance of being chosen, but there’s technically nothing to stop you from asking Visit Arctic Europe to name a northern lights show after your dog.

[h/t Travel + Leisure]