This story appears in the July 2012 issue of National Geographic magazine.
The scene: a tent on Mount Erebus, an active volcano on Ross Island, Antarctica. The tent is a four-cornered tepee modeled after those that Captain Robert Falcon Scott brought with him on his Antarctic expeditions more than a century ago. It is high enough at the center for someone five feet five inches tall to stand erect and has two vents at the peak that serve as chimneys. This particular tent is occupied by two people; both are in sleeping bags. Between the sleeping bags are a large box, a Primus stove, a couple of thermoses, and two pairs of heavy boots. It is too cold to read; even with gloves on, it is too cold to hold a book. Thus the inmates—of whom I am one—are passing the time by talking.
“What are your favorite microbes?” I say, dusting ice off my sleeping bag.
“It’s got to be those funky archaea,” says my companion, Craig Herbold, a large, thirty-something American with a taste for Japanese electronic music and an interest in astrobiology, the study of what life elsewhere in the universe might be like. He’s a postdoctoral researcher at the University of Waikato in New Zealand and the junior member of a team of three who have come here to look for life in the volcano’s hot soils. That’s right. He’s come to one of the coldest places on Earth to look for beings that thrive in heat.
Mount Erebus is the most southerly active volcano on the planet. It began to form about 1.3 million years ago and now stands 12,448 feet above sea level. Its slopes are covered with snow and ice, glaciers, crevasses, and the occasional lava flow, but steam usually rises from its summit, betraying the heat within. If Erebus were a dessert, it would be a reverse baked Alaska—frozen on the outside, hot in the middle.
It was discovered in 1841 during an expedition led by Sir James Clark Ross, who named it after one of his ships, the H.M.S. Erebus, which had in turn been named after the Greek god of primeval darkness. (Ross’s other ship, the H.M.S. Terror, gave its name to a smaller, extinct volcano that stands next to Erebus.) But no one reached the summit until 1908, when the mountain was climbed by members of Sir Ernest Shackleton’s Nimrod expedition—the expedition on which Shackleton led a team to within a hundred nautical miles of the South Pole but turned back so as to get everyone home alive.
Shackleton’s party hiked up Erebus. It took them five and a half days to get to the top, an undertaking that included a blizzard that kept them in their sleeping bags for more than 24 hours with nothing to drink, exposed them to temperatures of minus 30°F, caused one man to collapse with exhaustion, and gave another such an extreme case of frostbite that he ultimately lost a big toe.
Our journey was less arduous: We went by helicopter.
We were eight. There were the aforementioned Herbold and the two senior members of his research team: Craig Cary, a flamboyant American, and Ian McDonald, an understated Englishman, both biologists at the University of Waikato, both veterans of Antarctic research. Cary also has an appointment at the University of Delaware, and before he began working in Antarctica, he traveled regularly to the bottom of the sea to study organisms that live on deep-sea vents. Stu Arnold and Al Moore, two wind-burned New Zealanders with broad shoulders and broader accents, had the job of keeping us from, in Arnold’s words, “getting carnaged by the mountain.” Then there were Carsten Peter, the photographer, and his assistant, Daniel Jehle, both from the mountains of southern Germany. And then there was me: in Jehle’s words, “a girl.”
Despite its remote location and savage climate—the temperature averages minus 4°F in the summer and minus 58°F in winter—Erebus is a much studied volcano. Since 1972 a team of volcanologists, long led by Philip Kyle, a professor of geochemistry at the New Mexico Institute of Mining and Technology, has spent part of each austral summer on the mountain investigating matters such as the nature and frequency of its eruptions, the types of gases it gives off, and the age of its rocks.
The biology of the place has been less well documented. This is in part because up on Erebus most life-forms are microscopic. (The main exceptions are a few mosses and cyanobacteria—bacteria that, like plants, turn sunlight into energy and that can grow into colonies large enough for us to see.) Until recently the study of unknown microbes has been problematic: If you couldn’t grow it in the laboratory, you couldn’t describe it, let alone study it. And most microbes don’t take to laboratory life.
But it’s no longer necessary to grow a microbe to know something about it. In the past decade or so, genetic techniques have been developed that allow whole communities of microbes to be characterized by their DNA alone, giving us a far more complete picture of what lives where. So although life had been found in the hot soils of Erebus in the early 1960s, it’s only now that we’re able to do much in the way of studying it.
The hot soils of Erebus are dotted around its summit, most famously at a site called Tramway Ridge. Heat from the volcano melts the ice, creating small patches of hot, moist soil that become home to communities of mosses and microbes.
But here’s the thing. These patches are tiny islands of warmth in a sea of coldness. Although the soils themselves are hot—they can reach temperatures of 149°F—the air just above is not. Moreover, move a couple of feet away from the hot spot, and the soil temperature drops sharply. The acidity changes too. At the hot spot the soil is relatively neutral; a short distance away it’s harshly acidic. And lifeless: Cold, dry, and acid is unfriendly to life.
The presence of these islands raises intriguing questions. Which microbes live there, and where did they come from? Microbes can travel hundreds of miles on the wind. Did these blow in from the hot soils of volcanoes farther north? Or are the microbes on Erebus unique, and—this would be tremendously exciting—are they beings that have come up from deep within the Earth? The deep subsurface biosphere, where these organisms live in rocks far below the surface of the Earth, is one of the planet’s least known ecosystems. But it may be one of the largest—some estimates suggest that one-third of all bacteria on the planet might live there—and weirdest. Such microbes don’t make their living by drawing energy from the sun. Instead, they get energy from other sources, such as iron or hydrogen. This deep, dark ecosystem might also be among the Earth’s most primeval and could be home to life-forms that have long been charting a separate evolutionary course.
With such matters in mind, we set off.
Our trip began in the offices of Antarctica New Zealand, in Christchurch, where a jolly man called Chris issued us clothes: long underwear, two pairs of fleece trousers (thick and thin), two fleece jackets (ditto), a pair of windproof overalls, a light jacket of synthetic down, a windbreaker, a heavy jacket of real down, two pairs of boots, two pairs of thick socks, down tent slippers, nine pairs of gloves and mittens, a hat, a balaclava, a neck gaiter (a scarf shaped like a tube), snow goggles, and sunglasses. Because Antarctica is a desert, albeit a chilly one, Chris also gave each of us a widemouthed water bottle emblazoned with the command HYDRATE OR DIE! along with a list of the more common signs of dehydration.
Thus outfitted, we flew on a U.S. military transport plane—along with a few other passengers and some huge crates labeled “Do not freeze”—to Ross Island. We landed on an expanse of sea ice and stepped out into a landscape of white, blue, and gold. White: ice, snow, clouds. Blue: sky, certain kinds of ice, and where you can see it, open ocean. Gold: reflections of the sun off ice or clouds. But we didn’t have long to take it in, because we were met by a man wearing a gigantic bobbled hat and driven the short distance to Scott Base, New Zealand’s research station in Antarctica, for training.
Even in these modern times, when if something goes wrong there’s a reasonable chance of rescue, the practicalities of Antarctic travel are detailed and complex. “Make no assumptions,” said Arnold on the first day of our training. “Check all your equipment.”
McDonald leaned over to me and said, “Be sure to check that your thermos works—that it keeps water hot overnight and doesn’t leak.”
“Do you still have the water bottle we bought in New Zealand?” said Cary. I nodded. “Take it with you. It’s easier to drink from when you’re lying in the sleeping bag. If you drink from the one you were issued, you could pour water all over yourself—and oh boy, then you’re in trouble.”
Trouble, because wet means cold. At best, wet clothes and sleeping bags wick warmth away from your skin. At worst, they freeze into a suit of ice. One of the early explorers described how he left his tent in clothes merely damp from sweat and the humidity of his own breathing: “Once outside, I raised my head to look round and found I could not move it back. My clothing had frozen hard as I stood—perhaps fifteen seconds.” Yikes.
And so we tested thermoses and water bottles. We went on excursions to try out the clothes—different combinations suit different people—and went shopping at nearby McMurdo Station, the American base, for snowmobile masks. Also at McMurdo, a tattooed motorbike enthusiast called Toby taught us to “he-man” snowmobiles and explained how to change the spark plugs. Back at Scott Base we assembled sleeping kits. On the bottom a foam mat. Next an inflatable air mattress. On top of this a sheepskin rug. “Because we’re Kiwis and we like sheep,” said Arnold. Finally two down sleeping bags, one inside the other plus a polar fleece liner, inserted into a protective covering. All this done, we weighed everything, including ourselves, because helicopters are easy to overload.
Then we waited. The evening we were due to fly up the mountain, a big cloud was sitting on top of it. It wasn’t until late the next afternoon that the weather cleared enough for us to go.
First stop, Fang Glacier Camp, a site on the side of the volcano about 9,850 feet above sea level, where we were to spend several days letting our bodies get used to the altitude. Fang sits on a snowfield at the top of a glacier with a view of the mountains of the Antarctic continent on one side and of the snow-clad summit of Mount Terror on the other. The dark fang of rock for which the camp is named juts into the sky in front; it's the remnant of a caldera that collapsed hundreds of thousands of years ago. When the wind drops, the silence is total. No engines, birds, insects; no rustling leaves. Also, at this time of year the sun doesn’t set, and the light is bright—ski-slope bright—all the time. The only difference between noon and midnight is that at midnight the shadows are longer and the air is colder.
But Fang Camp is just that, a camp. Whereas our eventual base of operations, Lower Erebus Hut, has two small buildings (the eponymous hut and a shed) with electricity, heat, chairs, tables, and a stove with an oven, Fang consists of nothing but a row of tents pitched on snow.
Camping in this environment presents certain difficulties. For example, if you don’t eat your food within a few minutes of its being cooked, it will freeze. One morning I didn’t eat my cereal fast enough—and had to chip it out of the bowl. The only way to keep something warm is to heat it with your own body heat. This means you must keep it with you in your sleeping bag. Which is how I came to share my sleeping bag with lip balm, moisturizer, toothpaste, baby wipes, a camera, a watch, several pens, one pair of tent slippers, two pairs of gloves, two water bottles, three batteries, and three pee bottles.
Pee bottles? To acclimate to altitude you must drink one and a half to two gallons of liquid a day, all of which, incidentally, has to be made by melting snow. Drinking so much has obvious consequences. So at Fang there is a toilet tent. However, to go to the toilet tent you must get completely dressed; when it’s 40 below outside, you don’t sally forth in pajamas. For convenience, therefore, you stay in your tent and pee into bottles. When these are full, you go to the toilet tent and empty them. If they freeze—you’re stuck.
Meanwhile, there’s nothing to do at Fang but talk to your tentmate and melt snow. And so it was that Herbold and I came to be discussing the funky archaea.
“They’re so strange,” Herbold says. “I just can’t figure them out.”
Archaea are one of the three main branches, or domains, of the tree of life. (The others are bacteria, and eukaryotes—organisms with nuclei in their cells, like plants, fungi, and animals.) And although archaea can and do live in mundane places such as the open ocean, they are also celebrated for being extremophiles—life-forms that thrive in the most extreme environments this planet has to offer. Such as boiling acid—that sort of thing. So it’s not surprising that they should be lurking in the hot soils of Mount Erebus.
But these archaea are particularly mysterious. Found in soils that the group collected on previous trips to Erebus, so far they’re known only from their DNA sequences, which bear little resemblance to those of archaea that have been discovered elsewhere. This suggests, perhaps, that they have indeed long been charting their own evolutionary course. Are they from the deep subsurface? It’s too soon to tell.
“We found them on Tramway, right underneath the cyanobacterial mats,” Herbold says. “But we don’t know anything about their lifestyle.” He pauses, then adds, “The cyanobacterial mats are creepy. They look like matted hair that’s been splattered on the ground and partially digested.”
As we talk, the wind begins to pick up. Soon it’s too loud to hear each other. For the next 15 hours the wind hurls ice crystals at the tent and makes the walls rattle and flap. The only thing to do is lie huddled in the sleeping bag, listening.
It’s a relief when two days later we are deemed acclimated, the skies are clear, and a helicopter thuds into view.
The flight from Fang to Lower Erebus Hut is brief. But you arrive in a different landscape. Above, the crater of Erebus, steaming gently. Two buildings, the hut and the shed. An array of solar panels. And a row of fantastically shaped ice towers. The largest looks like an astronaut, and the others look as if they’re following in procession. I’m not alone in seeing figures in the ice towers. Shackleton’s men took a photograph of themselves with one that they thought resembled a lion. And as they surmised, the ice towers mark the sites of fumaroles—vents where the volcano releases hot, moist gases. When the moisture hits the cold air, it freezes, building structures that can be more than 35 feet tall.
Lower Erebus Hut is simple—one room plus an antechamber for frozen food—but compared with Fang, it’s a luxury hotel. Here’s a typical evening. Above the heater, a row of gloves drying. Herbold is in one corner, sterilizing equipment to take into the field the next day. McDonald is bringing in a vat of snow to make more water. Cary is talking about how Erebus is part of a larger study of volcanic hot soils: They already have soils from other Antarctic volcanoes, they went to Yellowstone last summer, and they plan to go to Costa Rica soon. Jehle is cooking. Peter is worrying about his cameras. Arnold is making a radio call to Scott Base. Moore is outside fixing one of the snowmobiles. And I’m washing up and thinking about the immensity of the landscape.
The actual doing of scientific fieldwork is often humdrum. But on Erebus the humdrum takes you to astounding places. Let me paint three scenes.
One, we’re wearing harnesses and hard hats and descending on ropes and ladders into an ice cave known as Warren Cave, which has been hollowed out by steam from the volcano. We unclip the harnesses about 40 feet below the surface of the mountain. The floor is moist, soft soil and rocks; the walls are ice. We are here to retrieve a temperature probe—one of 23 the group left on the mountain a year ago in the hopes of determining how much the soil temperatures change and thus whether these environments are relatively stable. As we move away from the entrance, the light fades, and we have to use flashlights. Any microbes living here do not depend on the sun. Now we have entered a cavern that glitters with clusters of delicate, feathery ice crystals. We stop to stare in wonder. Then Moore disappears down a corridor and after a few moments gives a shout. He’s found the probe.
Two, we’re standing on the rim of Mount Erebus. To get here we’ve driven as far as we could on snowmobiles, then hiked up a steep, slippery slope of scree—a mix of a glassy pumice and “Erebus crystals,” large oblong pieces of feldspar from lava bombs that have been tossed out by the volcano. It’s a gorgeous day: The temperature is around minus 13°F, the wind is light, the sky cloudless, the views huge. And the volcano is quiet. Whereas the crater is often full of swirling steam, today we can look down to the bottom, more than 750 feet below, and see the lava lake glowing redly. It’s an eerie sight, like looking at a conduit to the center of the Earth.
Up here the air is thin and walking is slow. I’m wearing a thermal shirt, thermal leggings, wool leg warmers, fleece trousers, heavy overalls, a down vest, a fleece jacket, two down jackets, two pairs of socks, heavy boots, three pairs of gloves, a balaclava, a hat, a snowmobile mask, a neck gaiter, ski goggles, and two hoods. Dressed like this, I am bulky and clumsy but warm. Just. As long as we keep moving.
But we’ve stopped. Herbold is on his hands and knees digging, looking for another of the temperature probes. I hope he finds it soon; I want to start moving again. I have a sudden sense of vulnerability, of being in a landscape that is not benign.
Three, Lower Erebus Hut. Outside, a swirling storm. The door crashes open. Arnold and Moore stride in, their jackets icy, their faces grave. Arnold tosses an ice ax onto the table. It’s broken; part of the top has sheared off because of the cold. There will be no ice climbing this afternoon. But we can enter the biggest of the nearby ice towers—the one that looks like an astronaut—and drill an ice core from inside.
Inside, the air is moist and warm. The floor is rocky, with a dusting of ice. Sky is visible through an opening high above. The drill bit looks like a boy-teen fantasy. It’s enormous—three feet long—and bright yellow, with a thread of lurid orange. It takes two men to operate, one to cradle it in position, the other to push it into the side of the tower. The interior of the bit is hollow, and pushed like this, it fills with a core of ice, much as an apple corer fills with apple.
Success! Arnold and Cary remove the ice core from the drill bit and stow it in a bag. The hope is that such cores will contain microbes that have been lofted from inside the volcano and then frozen into the ice, giving a window into the microbial life in the vent below.
Two weeks after going up the mountain we come down. A few days after that McDonald and Cary and I fly back to New Zealand, along with boxes of samples destined for the laboratory—“where the real work gets done,” says Cary. Shortly before the end of the flight a man comes over to McDonald and me and asks if we’d like to come to the cockpit for the landing. Yes please!
We are landing at sunset. Strange how refreshing the impending darkness is—how starved for darkness we have been. Strange too the lush, saturated colors of the New Zealand spring. It’s like coming back into a Technicolor world.
It’s like coming back to Earth.