Dave Marchant believes he has
discovered ice that is 10
million years old.
Photo by Peter West for National
The extraordinary nature of this condition was brought home to me by Alexander in a dramatic demonstration. From out of a freezer in the Crary Lab aquarium, Alexander took a beaker of supercooled water — not seawater, but very pure regular water, which can be forcibly chilled to around -4°C without freezing (unlike tap water, which is laced with impurities and would inevitably freeze at this temperature). Into the beaker Alexander dropped a tiny sliver of ice. As I watched, a wave of crystallization spread out from this seed, the imprint of its genesis visible in a shimmering pattern radiating from the center and resembling the delicate architectonic structures in mineral exhibits at science museums. We are so used to seeing ice in its featureless, ice-cube-tray form, I had not realized it could behave this way.
In Alexander’s demonstration, the merest fragment of ice “viralized” the beaker, forcing its contents from a liquid into a solid state. So why don’t the fish freeze when theyingest? The reason turns out to be stranger than anything biologists have dreamed of, nature once again besting man in its protean imaginative potential. DeVries has discovered that the fish produce a protein — called an antifreeze glycoprotein — that envelops the ice crystals and ferries them off to their spleens. By surrounding the ice in a protective shell, the glycoprotein prevents it from viralizing the liquid in the fish’s cells.
“This is entirely different from the way that most antifreezes work,” DeVries explained, his voice revealing the childlike awe that even the most seasoned scientists often feel in the face of nature’s fecund creativity. The liquid that Northeasterners pour into their car radiators, for example, prevents solidification by lowering the freezing point of the water. It’s the same principle as increasing the salinity. With the notothenioids, however, nature has hit upon a completely different strategy. I asked DeVries if this radical methodology wasn’t more akin to an immune response (immune cells also send special proteins to disable viruses), and he seemed to like the analogy.
Alexander had told me that DeVries had dreamed the notothenioid protein would revolutionize ice-cream production. More expensive, creamierice creams have smaller ice crystals than cheaper, less smooth varieties, and reducing crystal size is apparently a major goal of ice-cream makers the world over. DeVries realized that his fish protein could solve this culinary conundrum, but according to Alexander he also decided it would be hard to persuade consumers to purchase an ice cream made from genetically engineered fish proteins, and the scheme never took off.
Polar opposties: the old South
Pole station is being buried by
ice. (Snowfall in the Antarctic
doesn't melt; it simply
builds up.)Photo by Peter West
for National Science Foundation
The South Pole
Nowhere are the contingencies of living with ice more apparent than at the South Pole, that mythical singularity around which our world revolves. Geographically, the South Pole is located on a vast plateau atop a bed of ice three miles thick and spreading out for hundreds of miles in all directions. Seventy percent of the world’s fresh water is locked up in the Antarctic ice; if all of it were to melt, global sea level would rise 200 feet.
Flying in on a C-130 Hercules jet fitted with landing skis, it is hard not to be awed by the overwhelming whiteness of the place. With each passing mile, the utter purity of the landscape takes one visibly farther from the dominion of man. As we passed over the Transantarctic mountains, one of the young pilots from the contingent of Air National Guards who are stationed on the continent each austral summer pointed out an enormous, snaking path. White on white, its sinuous curve betrayed itself only by the most delicate variations in tone on the striations at its edge. It was one of the Antarctic interior’s monumental glaciers, some 20 miles wide, the pilot told me. Others in the region are up to 50 miles across. As happens so often here, it is almost impossible to judge scale, and neophytes constantly underestimate both distance and size.
We are used to thinking of ice as a static commodity, but a surprising lesson from the Antarctic is that ice has rhythms and flows of its own. Aside from the glaciers, whose dynamics scientists are only just beginning to understand, the edges of the continent are laced with vast “ice streams” that ebb and flow like tides. The Pole itself eludes our grasp because the plateau on which it resides is slowly moving. Each year on January 1, the skeleton crew wintering over at the NSF’s Amudsen-Scott South Pole Station place a flag in the frozen tundra at the precise geographic point of the Earth’s axis. Over the course of the following year it will be carried some 10 meters away, so that standing on the point today one sees a line of pennants stretching into the distance.
The new station under
construction is built on
columns that can be jacked
up, and is expected to last
50 years.Photo by Peter West
for National Science Foundation
This true or “geographical Pole” is complemented by the more permanent installation of a “ceremonial Pole,” a point marked by a soccer-ball-size sphere of polished steel surrounded by a semicircle of national flags from the countries that claim a stake in the continent. Ostensibly, the reason for each nation’s presence is the opportunity for scientific research, but as Alexander noted, the imagined mineral wealth beneath the ice is too juicy a potential prize not to have a hand in. Officially, the entire continent is a global commons; unofficially it is carved into chunks known as “dependencies” claimed by nations such as Argentina, Chile, New Zealand, France and the U.K.
The idea of possessing such a tractless immensity may seem ludicrous, but historically the first step toward ownership is habitation, and, in that sense, the U.S. stands alone at the Pole. Since the International Geophysical Year of 1957, the U.S. has maintained a permanent station at the Pole, and, as we ramp up for the 50th anniversary in 2007-2008, the most recent of its three incarnations is being completed.
The new South Pole Station is not merely an upgrade but a necessity, for the previous station, like the one before it, is being inexorably buried in ice. (Rather than melting, snowfall here simply builds up as part of the mass.) The new station too will eventually be engulfed, but not for a considerably longer period than its predecessors, said Dr. Jerry Marty, the NSF engineer who is in charge of its construction. In an innovative feat of engineering, the entire building is supported on columns that will gradually be jacked up over the next 40 to 50 years. “By that time,” Marty said, “who knows what technology we’ll have?” Building under these extreme conditions is the closest humans have come to building on another world, and according to Marty, NASA is keeping a close eye on the station’s progress.
Whatever our leaders’ territorial aspirations, the South Pole is a superb location for doing science, and the station is surrounded by a cluster of major scientific instruments. Under the auspices of the NSF, scientists from all over the world come here to study the atmosphere, the ionosphere and the magnetosphere. They monitor cosmic rays and have placed seismic instruments in the ice able to detect a nuclear detonation anywhere on Earth. Above all, they come here to study the cosmos, for with its pristine skies and its six-month-long night, the South Pole is an astronomer’s paradise. Several large telescopes are located in the region, and a huge new millimeter-wave telescope is currently under construction.
Ironically, the most exciting astronomical project at the South Pole directs the gaze of its instruments not to the sky but down through the frozen plateau. Known as “IceCube,” it will be the world’s first neutrino telescope and the largest-ever scientific instrument. Instead of recording electromagnetic waves, IceCube will record tiny subatomic particles that are emitted by violent cosmological phenomena such as black holes, quasars and colliding galaxies. All of its 4,200 electronic sensors will be buried within the ice, which will itself act as a particle detector. Because the ice here is so pure, neutrinos can be detected by the tiny flashes of blue light known as Cherenkov radiation that are emitted during collisions with other particles.
During my day at the Pole, I was given a tour of the IceCube site by Dr. Darryn Schneider, a wry and windblown Australian astronomer with a knack for large data systems who is in charge of coordinating the signals from all 4,200 sensors within the computational framework. “There is no way this would be possible without computers,” Schneider told me. The entire apparatus, which consists of more than a million pounds of equipment, is a multinational effort involving hundreds of scientists and engineers spearheaded by the University of Wisconsin, where Schneider is based.
While handling the IceCube data is a difficult task, it pales beside the challenge of setting the sensors into the ice. As Schneider explained, the 4,200 individual instruments will be deployed in groups of 60, strung along a cable. In all there will be 70 sensor “strings,” with each string deployed into a separate hole 2.4 kilometers deep. The sensors themselves — each a package of exquisitely sensitive electronics encased inside a glass sphere — will be arrayed at depths between 1.4 and 2.4 kilometers, over a field of 1 square kilometer. (IceCube takes its name from the fact that the total detector array will occupy a volume of approximately one cubic kilometer.)
All this is fine in principle; in practice, no one has ever dug so many holes so deep into ice. Add to this the Antarctic Treaty’s injunction against polluting, and IceCube’s engineers cannot use any kind of traditional drilling equipment (which is typically powered by gasoline that seeps into the surrounding ground). The only way to drill these holes without polluting the ice, Schneider said, is to use hot water, and a good deal of IceCube’s $272 million budget has been spent on designing and building the hot-water drilling equipment.
The vast bulk of that machinery had arrived a few weeks before I did and had only just been installed several hundred meters from the new station. Much of it is housed in two long rows of bright-orange shipping containers, inside of which is the equipment to heat the water. Schneider opened the door of one container to show me what it all looked like. “Basically, they are modified car-wash units,” he said. Heating the water is one problem, getting it is another. The South Pole has ice galore but no liquid water. As with the station itself, water is obtained by melting ice inside what is known as a “Rod well.” Schneider took me over to a tall piece of pipe sticking out of the ice like a spout. About 30 feet below us, he said, hot water had been used to create a cavity or bubble, in turn generating more liquid, which was pumped back up to the surface. All of the IceCube holes would be “dug” with water pumped out of this Rod well, then heated to a scalding temperature by the car-wash boilers.
The trick, said Schneider, is that “The entire hole must be dug in a single hit.” The drill head is on the tip of a cable two and a half kilometers long, and once it has been sunk, the drill would be lost if the water were to freeze around it. This season the team tested the system successfully with a single hole, and, assuming things go according to plan, they will drill the rest over the next five years. One measure of the scale of this massive engineering project is the sheer amount of energy required to make each hole. Some 7,000 gallons of gasoline will be burned by the generators in heating the water for every individual hole. Or, as Jerry Marty put it, that’s nearly three C-130 cargo loads of petrol apiece! One of the more curious aspects of the Antarctic enterprise to date is that while it is verboten to leak hydrocarbons into the ice, there are no limits on the amount you can pump into the air.
Once the new instrument is up and running, Schneider and his colleagues will be able to measure precisely where cosmic neutrinos are coming from. Theories predict that they are emitted by supernovae and by the black holes believed to reside at the hearts of most galaxies?. IceCube should be able to confirm or deny these theories, and will help astronomers to search for the mysterious dark matter that permeates much of our universe.
The Oldest Ice on Earth
I had seen plateaus of ice and rivers of ice and fish that defied ice, and finally, two days before I was due to leave “the ice,” word came in that the following day I would be able to visit Dave Marchant and the world’s oldest ice. At the South Pole, I thought I had seen the most spectacular landscape Antarctica had to offer, but NSF representative Peter West had warned me that nothing compared to the raw beauty of Beacon Valley.
Taking off around midday from the McMurdo helo-port, the first 40 minutes took us cruising over the frozen tundra of the Sound. Below us, the ice was a vast Abstract Expressionist canvas, an endless vista of multihued and infinitely variegated white. Paul Murphy, our young English pilot, explained that early in the season the ice is clean with no tonal shades, but as the summer progresses dust blowing over from the McMurdo Dry Valleys paints a subtle pattern the pilots call sustrugi. Reaching the far side of the sound, we headed along the Farrar Glacier, its boundary with the sea marked by patches of brilliant blue “re-freeze” that is the hallmark of pure glacial ice.
We were heading inland, deep into the heart of a region first explored by Robert Scott and the great Antarctic explorers of the early 20th century. Suddenly Murphy banked left and we turned into a barren valley, the ground beneath us bare as the moon. On either side loomed towering cliffs, striped with huge bands of black and brown rock, each recording a different geological era. Just as we entered, it began to snow, which may sound like a mundane event, but is actually not so common. The Dry Valleys are so called for their extremely low precipitation rates — the region being, in Marchant’s words, a “hyperarid desert.” (For my previous article on the Dry Valleys, see www.laweekly.com/ink/05/11/features-wertheim.php.)Through the swirl of the snow, the midday sun was suffused into an unearthly radiance, and the striations of the cliffs seemed to glow from within.
Marchant’s encampment turned out to consist of just a tent and a grad student? — several other team members had already decamped. Oddly, apart from the snow, there was little ice to be seen, and the ground around us was covered in rubble. Marchant was clearly a man accustomed to the cold; his cheeks showed patches of recent frostbite damage, and his eyes had a glittering look that I was later told was likely due to a bout of snowblindness. From the moment we arrived, he bubbled forth about his beloved ice, which turned out to be a great deal closer than I’d imagined. Actually, he said, I was standing on it; the rubble was merely surface debris covering an ancient glacier that was spilling down in toffeelike waves from the top of the mountains behind us. The ice itself was less than a meter beneath my feet.
Inside the tent, Marchant pulled out an aerial photograph and started to describe the valley’s terrain. “Here,” he said, pointing to a spot near the top of the mountain, “we know this ice is 300,000 years old. And here,” pointing to a spot farther down the slope, “we know that’s 1.5 million years. And here, farther down, it’s 4 million.” All this was uncontroversial, Marchant said. But then he pointed to a place on the Valley floor not far from where the tent was pitched: “Here,” he said, “we believe this ice is 10 million years old.”
Marchant admits that his claim is controversial, and another glaciologist I spoke with back in the States disputed his evidence. But Marchant also has his supporters, and if he is right, he’ll have found a place with a record of the Earth’s climate dating “back into the Pliocene and even into the late Miocene era,” for trapped within glacial ice are tiny air bubbles containing pristine samples of the atmosphere from each era in which ice was laid down.
Initially, even Marchant was skeptical about his most ancient finds: “At first we thought this ice couldn’t be 10 million years old,” he told me, “but all the data we’ve generated over the past decade has been telling us it is.” Marchant wanted to take me on a walk to see some of his evidence, but the snowstorm was intensifying, and Murphy suddenly determined that unless we intended to stay the night we would have to leave immediately. Marchant directed Murphy to fly over the polygonal formations he had wanted me to see, forms that he said can occur only when ice has sublimated (or evaporated) from below the surface. “You see the same formations on Mars,” he said, evidence, he thinks, that there is also ice just beneath that alien ground.
As Murphy swooped the helicopter low over the fractured forms on our way out of the valley, Marchant’s voice crackled cheerily over the radio, inviting us to change our minds and stay out the storm. There are plenty of sleeping bags, he enthused, and, hey, “It’s chili night!”