CLOSE

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
Original image
FRED TANNEAU/AFP/Getty Images
arrow
Animals
Fisherman Catches Rare Blue Lobster, Donates It to Science
Original image
FRED TANNEAU/AFP/Getty Images

Live lobsters caught off the New England coast are typically brown, olive-green, or gray—which is why one New Hampshire fisherman was stunned when he snagged a blue one in mid-July.

As The Independent reports, Greg Ward, from Rye, New Hampshire, discovered the unusual lobster while examining his catch near the New Hampshire-Maine border. Ward initially thought the pale crustacean was an albino lobster, which some experts estimate to be a one-in-100-million discovery. However, a closer inspection revealed that the lobster's hard shell was blue and cream.

"This one was not all the way white and not all the way blue," Ward told The Portsmouth Herald. "I've never seen anything like it."

While not as rare as an albino lobster, blue lobsters are still a famously elusive catch: It's said that the odds of their occurrence are an estimated one in two million, although nobody knows the exact numbers.

Instead of eating the blue lobster, Ward decided to donate it to the Seacoast Science Center in Rye. There, it will be studied and displayed in a lobster tank with other unusually colored critters, including a second blue lobster, a bright orange lobster, and a calico-spotted lobster.

[h/t The Telegraph]

Original image
Courtesy Murdoch University
arrow
Animals
Australian Scientists Discover First New Species of Sunfish in 125 Years
Original image
Courtesy Murdoch University

Scientists have pinpointed a whole new species of the largest bony fish in the world, the massive sunfish, as we learned from Smithsonian magazine. It's the first new species of sunfish proposed in more than 125 years.

As the researchers report in the Zoological Journal of the Linnean Society, the genetic differences between the newly named hoodwinker sunfish (Mola tecta) and its other sunfish brethren was confirmed by data on 27 different samples of the species collected over the course of three years. Since sunfish are so massive—the biggest can weigh as much as 5000 pounds—they pose a challenge to preserve and store, even for museums with large research collections. Lead author Marianne Nyegaard of Murdoch University in Australia traveled thousands of miles to find and collected genetic data on sunfish stranded on beaches. At one point, she was asked if she would be bringing her own crane to collect one.

Nyegaard also went back through scientific literature dating back to the 1500s, sorting through descriptions of sea monsters and mermen to see if any of the documentation sounded like observations of the hoodwinker. "We retraced the steps of early naturalists and taxonomists to understand how such a large fish could have evaded discovery all this time," she said in a press statement. "Overall, we felt science had been repeatedly tricked by this cheeky species, which is why we named it the 'hoodwinker.'"

Japanese researchers first detected genetic differences between previously known sunfish and a new, unknown species 10 years ago, and this confirms the existence of a whole different type from species like the Mola mola or Mola ramsayi.

Mola tecta looks a little different from other sunfish, with a more slender body. As it grows, it doesn't develop the protruding snout or bumps that other sunfish exhibit. Similarly to the others, though, it can reach a length of 8 feet or more. 

Based on the stomach contents of some of the specimens studied, the hoodwinker likely feeds on salps, a jellyfish-like creature that it probably chomps on (yes, sunfish have teeth) during deep dives. The species has been found near New Zealand, Australia, South Africa, and southern Chile.

[h/t Smithsonian]

SECTIONS

arrow
LIVE SMARTER
More from mental floss studios