They finally uncover the disturbing mystery that causes the “Blood Falls” in Antarctica

In the midst of the vast and brilliant white landscape of Antarctica, situated between the sublime ice of a blue glacier are the famous Blood Falls” or “Sangre Cataratas” named for their vibrant reddish color that simulates blood and cascades down.

Discovered in 1991 during the Terra Nova expedition to Antarctica, the British geologist Thomas Griffith Taylor observed something no human had ever seen: a strange, bloody waterfall that appeared in the middle of the ice.

Located at the edge of Taylor Glacier in the McMurdo Dry Valleys, it has taken experts more than a century to figure out what really causes the oddly colored waterfall – until now.

Recently, Ken Livi, a scientist in the Department of Materials Science and Engineering at the Whiting School uncovered the haunting mystery using powerful transmission electron microscopes at the Johns Hopkins Materials Processing and Characterization Facility.

Livi examined water sample solids from “Blood Falls” and found a large number of tiny iron fragments. The iron-rich nanospheres oxidize, making the water appear red.

“As soon as I looked at the images under the microscope, I noticed that there were these little nanospheres and they were rich in iron, and they had many different elements besides iron (silicon, calcium , aluminum, sodium) and they all varied,” Livi said in a statement. .

It is the first time that the iron nanospheres which explain the red color of the waterfall have been detected, and although more than 100 years have passed, it must be taken into account that the nanospheres are extremely small round objects, equivalent one-hundredth the size of an average human red blood cell, with unique physical and chemical characteristics.

The unique composition of these elements in the nanosphere is what gives the salty glacier water a bloody color as it passes oxygen, sunlight and heat.

Livi worked on the research as part of a team that included experts from other institutions, such as Jill A. Mikucki, a microbiologist at the University of Tennessee who has studied Taylor Glacier and Blood Falls for years. The findings were published by Johns Hopkins University in the journal Frontiers in astronomy and space science.

The scientist explained that nanospheres have not been identified before, not only because they are extremely small, but also because before it was believed to be a type of mineral that caused the color. But they are actually nanospheres, which are not minerals.

“To be a mineral, atoms must be arranged in a very specific crystal structure. These nanospheres are not crystalline, so methods previously used to examine solids failed to detect them,” Livi said.

The newly observed tiny particles come from microbes millions of years old and are abundant in the meltwater of the Taylor Glacier. The ancient iron- and salt-rich waters beneath the glacier contain strains of bacteria that may not have changed for millennia.

Scientists believe that understanding Blood Falls and glacier lifeforms could inform research and understanding of life on other planets, such as Mars, which have similarly inhospitable environments.

In fact, that’s how Livi became interested in tackling the mysteries of the Falls. “With the advent of Mars Rover missions, there was interest in trying to analyze the solids coming out of the waters of Blood Falls as if it were a Martian landing site,” he said. declared. “What would happen if a Mars Rover landed in Antarctica? Would he be able to figure out what was causing the “Blood Falls” to turn red? This is a fascinating question and one that several researchers have addressed.”

Previously, an Antarctic researcher, Mikucki, was part of the team that first identified the presence of living organisms in the lake below the Taylor Glacier, using devices and methods identical to those employed by rovers crossing the surface of the red planet. But the answer to why the water was that color remained unclear.

The new findings suggest that if the robots like the rover do not have the proper equipment on board, they may not be able to detect all life forms present under a planet’s icy bodies.

If a Mars rover landed in Antarctica right now, for example, it wouldn’t be able to detect the microbial nanospheres that turn the terminus of Taylor Glacier into a red fan.

“Our work has revealed that the analysis performed by rover vehicles is incomplete in determining the true nature of environmental materials on the surface of planets. This is especially true for colder planets like Mars, where the materials formed can be nanometer-sized and non-crystalline. Therefore, our methods of identifying these materials are inadequate. To truly understand the nature of the surfaces of rocky planets, a transmission electron microscope would be needed, but it is currently not possible to place one on Mars,” he said.