Antarctica (45 page)

Soon, he was passing out, unable to swallow dribbles of hot milk without spewing it back up again, and lying on his bunk, too exhausted to clean up the mess. Somehow he managed to keep up his radio calls, cranking up the transmitter with the last of his strength, painfully spelling out jokes in Morse code in the hope that his friends back in Little America wouldn't notice the difference.

It was not even midwinter. The sun was three months away. In the past when he had been ill, he had wanted to be left by himself, but now he craved companionship and comfort. But he could not ask his friends for remote radio solace without arousing their suspicions and tempting them to risk themselves in a foolhardy attempt at rescue. Unlike Mawson, who had found himself without companions in a summer race against death because of unforeseen disaster, Byrd had chosen to be alone in the black heart of an Antarctic winter. He was very painfully aware of this: ‘You asked for it, the small voice inside me said, and here it is.'
²⁰

He couldn't even convince himself that it had been worth it for the sake of the science. Who knew what those rolls of paper and lines of meteorological figures were worth? He berated himself for his hubris. By the middle of June, this once proud Virginian lay sobbing in his bunk, all strength and hope dissipated, his face turned to the wall. Now his only fear was for his men, for the fate of his expedition, and for his family back at home. He wrote last letters to them all.

But still he continued to drag himself up, still tried to force food down. He had figured out that the stove must be to blame and was doing without it for as long as possible each day. The pools of vomit on the floor now froze. Frost started creeping up the walls of his shack. And yet he cranked up his transmitter, sent coded messages to his men, tried to pretend for their sake, if not for his.

They knew him far too well to be fooled. At the end of June, one of his men told him they had been refurbishing the tractors and airily suggested that they could make a night journey to make measurements of meteorites after the weather had warmed a little, but before the sun returned to spoil the view. They could perhaps come his way, and use his shack for shelter before the return journey. Byrd was torn. Suddenly this held out the possibility of rescue, but how could he allow his men to risk their own lives to save his?

In the end he authorised the journey, to be started in the middle of July, though they had to turn back if there was any trouble finding the trail, or if the weather blew in. The hope revitalised Byrd, but twice this hope was crushed as he dragged himself up aloft to light beacons for the men. Several times he thought he saw an answering flash on the horizon, but it was always a star, or a mirage. After the second of these attempts he wrote in his diary how he had lit a magnesium flare ‘making a tremendous blue hole in the night. It burned for about ten minutes. Then the darkness rushed in, and I was sensible of the ultimate meaning of loneliness.'
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For each time he dragged himself back down again, it was only to hear on the radio that the men had had to turn back.

The third time, the word from Little America was good, and the tractors seemed to be getting through. For the last 30 miles, Byrd lost all contact, and with it most of his hope. But he continued to light the beacons, and then, at last, at long long last, there was an answering light that did not disappear; and a rumbling sound to break the silence of the Antarctic night; and the shadowy shape of a tractor; and three men who climbed out and solemnly shook his hand. ‘Come on below,' Byrd said, ‘I have a bowl of hot soup waiting for you.' Then he climbed down the ladder and collapsed.
²²

It was another two months before Byrd was strong enough to make the return journey to Little America. And some time after that before he trusted himself to resume flying over West Antarctica to continue charting that unknown territory that even today remains both a mystery and a threat.

Byrd had learned his lesson—he would never again underestimate Antarctica. But it's not yet clear that we have learned ours. For as we belatedly scramble to understand the complex mechanisms driving the glaciers of West Antarctica, the continent has one more wild card to throw on to the table: not ice, but a huge reservoir of ready-melted, squirting, spouting water.
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Slawek Tulaczyk had never seen an ice stream in the flesh, let alone stood on one. He did all his analysis in his office, back home at the University of California, Santa Cruz. But after ten years of studying these great glaciers from afar he knew how they were supposed to behave. And something was definitely wrong. First there was the data from flights over two of the Siple Coast ice streams in 1998 and again in 2000. The planes had been firing lasers to measure the height of the ice. And for some reason the ice in 2000 seemed to be thirteen feet higher than in 1998. That was far too much to be explained by a bit of extra snowfall. Something had to be lifting the ice up from below.

Then some satellite data came in, showing ice heights and speeds in the same region in 1997. The satellite had made a couple of passes. And when he compared the data from 26 September with another twenty-four days later, Slawek found that some parts of the ice had slumped downwards by about half a metre, while other parts on a nearby stream had moved either up or down. ‘You look at that and ask yourself why? How can you change the ice surface so fast?' he says. There was only one explanation that either he or anyone else could think of.

Water. It had to be water, squirting beneath the ice streams, filling up hollows and emptying them again, lifting the ice like a jack beneath a car, then allowing it to fall as the water moved on.
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How could that be? Close to its surface, much of the ice sheet is colder than -58°F. Beneath this hard outermost face could there really be so much water squirting and lifting and pouring?

Slawek's idea might have seemed crazy, but for a parallel set of discoveries that had been taking place ever since the 1960s. Beneath Antarctica's mantle, in the deep dark places where ice met rock, it seemed that there were entire districts of hidden, liquid lakes. Nobody had ever seen or touched one of these lakes; they were buried under miles of ice and hadn't seen daylight for hundreds of thousands, perhaps millions of years. But researchers knew they were there thanks to the way ice can't help but betray its roots.

The surface of ice always shows a little of the topography that it is resting on. If there's a mountain down below, the ice surface will reveal its presence with a bump. If there's a valley, the surface will have a dip. And if there's a lake, there will be no topography at all. The lake water will be flat, and so will the ice floating above it. To find a hidden lake, you just need to find a large surface patch of completely flat ice.

And researchers have now found hundreds of them. Perhaps it shouldn't have been surprising. After all, the pressure of the overhead ice, and the heat coming from inside the Earth were together enough to take the ice to its melting point. All you then need is a suitable hollow or basin in the rock for the water to collect in and you have your lake. But still, the sheer number of these lakes has changed the way many researchers view the continent.

The current tally is nearly four hundred under-ice lakes, some of them huge.
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The first showed up back in the 1960s and as satellite data replaced laborious local flights more are showing up all the time. There are several under Concordia Station, at least one near the South Pole, and the crown jewel is beneath Vostok Station—a body of water the area of Lake Ontario but twice as deep, making it the seventh largest freshwater lake in the world.
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All this was intriguing enough, and many scientists had been itching to drill down into these lakes and see if they might contain some form of life. But nobody had thought they might be interconnected. Or at least, not until now.

It could have been a one-off. But then Duncan Wingham, who was using satellite data to measure the height of Pine Island Ice Shelf, noticed that a patch of ice in East Antarctica seemed to have lurched downwards by three metres. At the same time, several lakes nearby seemed to be filling up, each by about a metre. Duncan tracked the satellite data for more than a year as an invisible river the size of the Thames drained one lake and filled two more.
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And then in May 2006, just after Duncan's paper was published, Helen Amanda Fricker from Scripps Institute of Oceanography found that over a two-year period part of the Siple Coast ice had dropped by
thirty feet.
What's more, the region that had fallen was also flat. She had discovered a new lake, and the lake was emptying. Now she mapped the rest of the Siple Coast and found fourteen more areas where the ice was falling or rising, as water shifted beneath.
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This was happening everywhere! All over the continent it seemed that hidden lakes were filling and emptying and water was sloshing about with abandon. It was presumably moving for the same sorts of reasons that water moves around on the Earth's surface: one lake would fill to overflowing and the water would spill ‘down' to the next one. But ‘down' didn't necessarily mean the same thing here. Because of the intense pressure it exerts, the ice sheet overhead counts for far more than local hills and valleys when it comes to deciding where water should flow. So in the wacky world of Antarctica's underside there were lakes sloping down mountainsides, and waterfalls squirting uphill.

But what really shocked glaciologists was the speed of it all. Nothing beneath the ice was supposed to be able to change that quickly. Don Blankenship summed up the mood of the moment: ‘This thing that takes millions of years to change is being tickled by a process that happens on a timescale of months. I don't think anyone has yet been able to swallow what that means.'

And it's not just lakes. A student of Don's, Sasha Carter, has now discovered a whole new set of almost-lakes that he thinks may be marshes or wetlands. They are flat like the lakes, but their surfaces are rough. He calls them ‘fuzzy' lakes and thinks they could have patches of land poking through the water to prevent them being smooth. These under-ice wetlands could be regularly flooded by overflows from the regular lakes, and then pass the water on down the line.
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In fact, the latest calculations suggest that all the water in under-ice marshes could make the underside of Antarctica the world's largest wetland. If the numbers are right, there is more water trapped in sediments beneath the ice than in all the rivers, lakes, ponds and puddles on the rest of the planet.
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That's astonishing, but it should also be worrying. ‘Remember, this is the lubricant that's moving around,' says Don. ‘If it's down there it's slippery, and we don't know where the ice sheet's ticklish spots are.'

For instance, Leigh Stearns from the University of Maine has found that Byrd Glacier in East Antarctica speeded up for a year, and that its acceleration coincided exactly with the draining of a nearby under-ice lake.
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And Robin Bell from Lamont Doherty Earth Observatory in New York found several lakes at the onset of one of the fast-moving ice streams in East Antarctica—the Recovery Glacier, which flows out into the Weddell Sea. She believes the presence of the lakes has set the glacier sliding so quickly, by providing the sediments beneath with the water they need.
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‘Antarctica has two faces' Robin says. ‘It has the face it shows to the world and it has the one on the inside. And the inside face could be the one that really matters.'

I still can't get my head around this. This continent that is so forbidding, and cold, and dry, and slow, has a soft warm heart? While nothing changes on the outside, down below is a vital world of rise and fall, give and take, water slipping and sliding from place to place, perhaps taking the ice with it. The implications for us might be grave. Perhaps the ice is more vulnerable than we realised. Perhaps this vibrant inner life will boost our own activities and help send the ice sliding into the sea.

Of course that's troubling. But I can't help being intrigued. What would it be like to see that hidden face? To be down in the dark among the lakes and wetlands and floods and uphill waterfalls?

It turns out that there is one place where Antarctica's icy mask has slipped, back in the Dry Valleys of Antarctica, the home of Lake Hoare and Beacon Valley, and Battleship Promontory. This is the landscape so otherworldly that NASA scientists go there to imagine Mars; and where the life has found such extreme ways to survive—under lake ice, inside rocks, in holes on the tops of glaciers—that biologists use it to study what alien life might be like. But this dry and ancient terrain also bears the signs of something much closer to home.

 

‘Do you see these channels? Do you see them? That big channel coming down there, and those scooped-out benches, and the ripples on top where the water went over. That's a huge empty waterfall. You're standing at the top of a Niagara Falls!'

George Denton, from the University of Maine, is a veteran of veterans when it comes to Antarctica. His expertise is interpreting glacial landscapes, picking up clues like a forensic scientist, deducing what has gone before. He has been doing this for decades, and he knows the Dry Valleys probably better than he knows his own hand.

He worked long ago with Dave Marchant—whom I met in Beacon Valley looking for ancient ice and ash layers to date. In fact, George
taught
him how to do it back in the days when Dave was a fresh-faced student and George was his Ph.D. adviser. Dave and George are both now convinced that the Dry Valleys were once not nearly as dry as they are today. And on a late, late January night, when sensible people back in McMurdo were in bed, and the shadows were low and long, George had brought me out here to the valleys by helicopter to show me why.