On Antarctica’s Ross Island, some researchers are making their way through a series of subterranean caves. And rather alarmingly, these underground tunnels lie perilously close to an active volcano. But potentially risking life and limb may turn out to be worth it. When the experts examine the samples that they’ve collected, you see, they make a chilling discovery – one that could upend what we think we know about this icy continent.
Ross Island – where the team of specialists were carrying out their investigation – can be found not far from the shores of the Antarctic area of Victoria Land. And, interestingly, the island is actually a part of the Ross Dependency – a territory that lies under the jurisdiction of New Zealand. But, needless to say, this isolated environment doesn’t share a temperate climate with the Antipodean nation. On average, temperatures there tend to average out at a bitterly cold 1 °F.
What’s more, the surface of Ross Island is blanketed in thick ice sheets that generally make it difficult for any species of flora or fauna to thrive. Still, there is at least one other notable aspect to the landscape there: an active volcano known as Mount Erebus. And it’s close to this fearsome natural feature that the special network of caves has developed.
In fact, Ross Island features no fewer than four volcanoes – including Erebus. Yet some may consider this part of the world to have a rather misleading name. You see, as a sheet of ice links the landmass to the Antarctic shore, it may look as though it’s actually not an island at all.
That’s exactly what the island’s namesake believed when he first set eyes upon the area in 1841. Indeed, Sir James Clark Ross presumed that the icy region was simply an offshoot of the mainland. And the record was only put straight decades later when the team of the British Discovery Expedition ventured to Antarctica in the early 20th century.
Ross Island was in fact a camping site of sorts for some of the Antarctic pioneers who made the first trips to the continent. And even today, cabins created by those intrepid explorers remain intact at the location. These huts were constructed by members of two separate – and very famous – excursions helmed by Sir Ernest Henry Shackleton and Robert Falcon Scott.
Fast-forward to the present day, however, and even more complex man-made features have since materialized. In particular, the island houses a pair of important research facilities: the New Zealand-owned Scott Base and the U.S.’ McMurdo Station. The McMurdo operation is arguably the most significant of the two – not least because its buildings can potentially accommodate more than 1,200 people. For half a decade from 1987, Greenpeace also operated the World Park Base there.
It should be known, though, that Ross Island is rather on the small side, as it encompasses just 950 square miles of land – most of which is frozen and sheathed in snow. And yet this area close to McMurdo Sound is well above sea level. In fact, its most elevated peak is higher than any point found on Antarctica’s other islands.
And Ross Island has its fair share of lofty summits, too. The volcano Mount Bird is just a little less than 5,800 feet tall, for example, while Beeby Peak climbs to roughly 4,600 feet. The aptly named Mount Terror, meanwhile, tops out at just under 10,600 feet. Yet the tallest point of all can be found at the top of Mount Erebus.
Situated to the south of Ross Island, Erebus juts almost 12,500 feet into the sky. And, rather appropriately, the volcanic feature takes its name from a ship that had once been under the command of Sir James Clark Ross. Yes, the HMS Erebus was one of the vessels on the journey that saw Ross discover this part of Antarctica.
But Erebus has certainly distinguished itself since the explorer and his crew first stepped foot onto the island. Today, you see, it’s known as the most southerly active volcano on the planet. Barring Mount Sidley, Erebus also possesses the tallest peak of any Antarctic volcano – and that summit is high enough to earn itself a special accolade, too.
More specifically, Erebus has an ultra-prominent peak – otherwise known as an ultra. This designation is given to the top of a mountain that stands alone – and without any other summits getting near it – for at least 4,900 feet. There are said to be over 1,500 ultras across the world today.
Mount Erebus has also been measured as exhibiting the greatest level of activity of any volcano on Antarctica. And that’s not all: the highest point of the landmark even accommodates a lava lake, which makes it very special indeed. You see, relatively few volcanoes around the world have hosted lava lakes – which are just as they sound – within the last few decades.
But what does Erebus do when it blows? Well, although the volcano remains active, its blasts are fortunately rather weak. Typically, Erebus displays Strombolian eruptions that originate either within the lava lake or from the interior crater, with these explosions sending volcanic material shooting into the sky. And yet these periods of disruptive behavior can go on for a long time. According to Oregon State University’s Volcano World website, Erebus’ last eruption began in 1972 – and it didn’t finish for another 20 years.
In addition, Mount Erebus is deemed to be a polygenetic stratovolcano. As with other stratovolcanoes, then, it has a cone-like shape. Somewhat dauntingly, Erebus is also capable of erupting continually during a particular stretch of time. This marks it out from monogenetic volcanoes, which each erupt on just a single occasion.
And Mount Erebus also boasts what are known as ice fumaroles. A fumarole is a breach in the surface of the Earth through which different varieties of gases and steam can escape. In colder regions such as Antarctica, however, the ice close to these openings melts then refreezes itself into sometimes towering formations that appear to diffuse steam from their tips.
Erebus’s volcanic activity has also helped create something special: a network of caves beneath its surface. And the conditions present within these caverns are almost unique in Antarctica. Thanks to the warmth emitted from Erebus, the subterranean chambers are almost toasty – when compared to temperatures on the rest of the continent, anyway.
And it was these caves that Aaron Curtis – a representative of both NASA’s Jet Propulsion Laboratory and the Mount Erebus Volcano Observatory – set about investigating in December 2016. Curtis was also joined on the trip by other scientific professionals who were all aiming to learn more about Mount Erebus. Hopefully, then, the experts could determine the chemical make-up of gases exuded by the volcano – as well as how old the landmark’s rocks actually were.
Curtis himself, meanwhile, was also part of the Extreme Environments Robotics Group that was tied to the Jet Propulsion Laboratory. And as members of the collective had been attempting to create robots that would be capable of overcoming challenging landscapes, the researcher tried out a number of contraptions at Mount Erebus on their behalf.
In a 2017 interview with Astrobiology Magazine, robotics expert Aaron Parness explained just why it’s so important to get these machines up and running in such demanding environments. “Field testing shows you things that are hard to learn in the laboratory,” Parness said. “We jump on those opportunities. Even if the prototype isn’t ready to work perfectly, it doesn’t mean it isn’t ready to teach us lessons on how to make the next iteration better.”
In fact, Curtis tried out a variety of new technologies during his trip to Mount Erebus. One of these was a type of makeshift drill known as the Ice Screw End Effector (ISEE), with this device having specifically been created to assist a Limbed Excursion Mechanical Utility Robot, or LEMUR. And ISEE would not only help LEMUR to stick to ice walls, but it could also take specimens of the frozen stuff as the other machine moved.
Testing ISEE in varying conditions was important, too, as ice can vary greatly in terms of its consistency. Sometimes the substance may be fragile, while in other areas it may be robust – and yet the drill needs to rise to the challenge regardless. And Curtis spoke of these discrepancies to Astrobiology Magazine, saying, “The differences involved [in the ice] can be like trying to climb a marshmallow versus a light metal.”
In addition, Curtis fired up a robot known as PUFFER that is usually employed to investigate landscapes. When it’s not in use, PUFFER is relatively small and easy to store; in the field, though, it can expand itself in order to cover more terrain. And before Curtis tried the machine out, it had never actually traveled anywhere in icy conditions.
Yet another invention tested by Curtis was a light-finding device that can help draw up three-dimensional records of underground tunnels and chambers. The technology the sensor employs means that it can plot out a diagram of its surroundings just by analyzing any visual stimuli in its vicinity.
According to Curtis, though, it can be rather challenging to create three-dimensional maps in colder parts of the planet. After all, ice is highly reflective, and this can interfere with a computer’s ability to interpret visual information. Curtis added to Astrobiology Magazine, “Ice sparkles, and the sparkly crystals look different from each angle. It’s like a hall of mirrors.”
But it was worth persevering, as the caves under Mount Erebus are special for yet another reason. It’s said, you see, that these subterranean caverns have conditions that may be comparable to those found in other parts of the galaxy. And that’s especially important when it comes to investigating Europa – one of the moons of planet Jupiter. It’s been theorized, you see, that water may be present underground there, with this suggesting in turn that some form of life could exist on the celestial body.
Given this potential, then, Europa is understandably of great scientific interest. And while the climate of the moon is naturally different from anything found on Earth, there may be some parallels to what can be experienced underneath Erebus. Indeed, when talking to Astrobiology Magazine, Curtis revealed, “We think some features of these caves are similar to what you might see on a moon like Europa.”
Furthermore, if there is indeed life on Europa, it may well take the form of microorganisms existing below ground. And that’s exactly why Erebus is such a potentially important place to study. You see, there’s evidence to suggest that so-called extremophiles have been dwelling within its caves.
And a group of researchers claimed just that in a paper published in 2017 in the scientific journal Polar Biology. The team was comprised of specialists from Australia National University, which is located in the nation’s capital of Canberra, as well as New Zealand’s University of Waikato and the University of Maine.
For one, the caves under Mount Erebus are much warmer than anywhere else on Ross Island. Yes, while temperatures on the surface of that part of Antarctica are on average a perishing 1 °F, the interior of the caverns can reach a much kinder 77 °F. And in certain parts of these subterranean chambers, the ice is so lean that limited levels of light can sneak in. Theoretically, then, life could exist there.
And on the subject of the conditions under Erebus, the BBC quoted Dr. Ceridwen Fraser – one of the researchers involved in the study. “You could wear a T-shirt in there and be pretty comfortable,” Fraser suggested. “There’s light near the cave mouths, and light filters deeper into some caves where the overlying ice is thin.”
In the search for signs of life, then, Fraser and her colleagues took soil specimens from inside Erebus’ caves. And upon analysis of these samples, the experts concluded that these exhibited signs of DNA from eukaryotes. Eukaryotes are a wide-ranging group of organisms that include algae, flora and fauna.
And while elements of that DNA did appear to resemble those found in species from other parts of Antarctica, that was far from all. You see, some of the genetic material didn’t seem to correspond to any previously known creature or plant. As such, then, it’s possible that the caves have played host to organisms that have never before been observed.
Fraser appears to be enthusiastic about these findings, too, judging by her comments to the BBC. The bio-geographer said, “The results from this study give us a tantalizing glimpse of what might live beneath the ice in Antarctica. There might even be new species of animals and plants.”
However, Professor Laurie Connell – who was also involved in the research – was reluctant to jump to any firm conclusions regarding the nature of life below Erebus. “The next steps will be to take a closer look at the caves and search for living organisms,” she said to the BBC. “If they exist, it opens the door to an exciting new world.”
Plus, there may yet be further discoveries of this nature on Antarctica. After all, there are many other active volcanoes dotted throughout the continent, with every one of these possessing carved-out caves of some description. And while in most cases these tunnels and chambers are unreachable in person, radar-mapping procedures could potentially help scientists to learn more about them.
According to a 2017 press release from the Australian National University, though, fellow researcher Dr. Charles Lee is cautious about the possibilities of unearthing life elsewhere on Antarctica. “We don’t yet know just how many cave systems exist around Antarctica’s volcanoes or how interconnected these subglacial environments might be,” Lee is quoted as saying. “They’re really difficult to identify, get to and explore.”
Regardless, though, the work undertaken by Lee, Connell, Fraser and their colleague Craig Cary may well have important implications for understanding what lies within Antarctica. There could in fact be varied populations of organisms yet to be discovered on the continent – although naturally that’s yet to be determined for sure.
And in their research paper, the team seem to encourage others to follow in their lead by writing, “To date, biological studies of the cave systems in Antarctica have been limited to assessments of fungal and microbiological diversity. Our results highlight the importance of investigating these cave systems in greater detail – despite the field challenges associated with such an endeavor – to confirm the presence of living macrobiota.”
Erebus’ name is somewhat apt, too. You see, while the volcano’s moniker may actually pay homage to Ross’ vessel, it also belongs to a god from ancient Greek mythology who is said to have ruled over the underworld. And on Ross Island, Erebus safeguards the caves that lie below – ones that could host a rich world of their own.