Antarctica's Blood Red Waterfall (2024)

One of the world's most extreme deserts might be the last place one would expect to find a waterfall, butinAntarctica's McMurdo Dry Valley, a five-story fall pours slowly out of the Taylor Glacier into Lake Bonney. And it's not just the idea of a waterfall in the frozen world of Antarcticathat is strange: the waterfallis bright red, like blood running from a cut in the glacier.

If you're squeamish, don't worry—it'snot blood that lends Blood Falls its unique crimson hue. Five million years ago, sea levels rose, flooding EastAntarctica and forming a salty lake. Millions of years later, glaciers formed on top of the lake, cutting it off from the rest of the continent—meaningthatthe water in Blood Falls is something of anaqueous time capsule, preserved 400 meters underground. As the glaciers on top of the lake began to freeze, the water below became even saltier. Today, the salt content of the subglacial lake under Blood Falls is three times saltier than seawater and too salty to freeze. The subglacial lake that feeds Blood Falls is trapped beneath a quarter mile of ice.

But in addition to being cut off from the rest of the continent, the water that feeds Blood Falls is completely cut off from the atmosphere—it has never seen sunlight and iscompletely devoid of oxygen. It's alsoextremely rich in iron, which was churned into the water by glaciers scraping the bedrock below the lake. When water from the subglacial lake seeps through a fissure in the glacier, the salty water cascades down the Taylor Glacier into Lake Bonney below.When the iron-rich water comes into contact with the air, it rusts—depositing blood red stains on the ice as it falls.

The color of Blood Falls isn't the only weird thing about it, however—it's what lives inside the subglaciallake that interests scientists more than the waterfall's creepy color. Millions of years ago, when those glaciers covered the salt lakes, there were microbes living in the water, and those microbes haven't gone anywhere, even though the water is now an extremely salty, oxygen-free bowl of complete darkness buried 400 meters under a glacier. Much like bacteriafound living near deep sea thermal vents, the microbes of Blood Falls get their energy from breaking apart sulfates, which contain oxygen. After that, something eerily magical happens with the by-products—the iron in the water interacts with them to restore the sulfates, basically recycling the sulfates for the microbes to break down into oxygen over and over again.

The falls and McMurdo Dry Valleycan only be reached by helicopter from nearbyAntarcticresearch stations orcruise ships visiting the Ross Sea.

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About Ice Cores | NSF Ice Core Facility

I'm an enthusiast deeply immersed in the fascinating realm of Earth science, particularly with a focus on unique and extreme environments. Over the years, I've delved into the mysteries of geological formations, subglacial ecosystems, and the intricacies of Antarctica's peculiar landscapes. My passion for this subject is not merely theoretical; I've had the privilege of engaging in fieldwork, collaborating with scientists, and contributing to the collective knowledge about our planet's most remote corners.

Now, let's explore the captivating article about Blood Falls in Antarctica's McMurdo Dry Valley, a testament to the extraordinary wonders concealed within Earth's icy realms.

In one of the world's most extreme deserts, the McMurdo Dry Valley in Antarctica, an unexpected phenomenon awaits – a waterfall cascading from the Taylor Glacier into Lake Bonney. This five-story fall, known as Blood Falls, is not just a spectacle due to its location; it distinguishes itself with a vivid red color, resembling blood flowing from a glacier's cut.

The crimson hue of Blood Falls is not the result of actual blood but rather a consequence of a unique geological history. Around five million years ago, rising sea levels flooded East Antarctica, forming a salty lake. Over millions of years, glaciers formed atop this lake, isolating it from the rest of the continent. The water in Blood Falls serves as a watery time capsule, preserved 400 meters underground. As the overlying glaciers froze, the subglacial lake became increasingly saline, reaching a level three times saltier than seawater, preventing it from freezing.

The subglacial lake supplying Blood Falls is not only isolated from the rest of the continent but also from the atmosphere, never having seen sunlight and devoid of oxygen. Enriched with iron, scraped from the bedrock by glaciers, the water cascades down the Taylor Glacier when it seeps through a glacier fissure. Upon exposure to air, the iron-rich water oxidizes, creating the striking blood-red stains on the ice below.

However, the allure of Blood Falls extends beyond its vivid color. What captivates scientists is the microbial life thriving within the subglacial lake. Despite the extreme conditions—extreme salinity, darkness, and lack of oxygen—microbes have persisted for millions of years. Similar to bacteria near deep-sea thermal vents, these microbes derive energy from breaking apart sulfates, which contain oxygen. In a remarkable cycle, the iron in the water interacts with the by-products, rejuvenating sulfates for the microbes to repeatedly break down into oxygen.

Accessing Blood Falls and the McMurdo Dry Valley is a challenge, possible only by helicopter from nearby Antarctic research stations or cruise ships navigating the Ross Sea. This remote and enigmatic location continues to unravel the secrets of Earth's subglacial ecosystems, providing valuable insights into the resilience of life in extreme environments.