Antarctica (46 page)

It was a spectacular journey. From our refuelling stop at Marble Point, just across the Sound from McMurdo, we passed over the flat grey ice of Lake Fryxel, and climbed up Canada Glacier with its smooth snow and tumbled blue crevasses. And then we were high in the Asgard Range, turning and weaving between the rows of chocolate-coloured peaks. George was in the co-pilot seat, taking photograph after photograph through the helicopter's bulbous windows. I was sitting behind, holding on, when the voice of Gregg Leibert, the pilot, came into my headphones:

‘Don't worry. I'm not going to fly into a mountain.'

‘Please don't.'

‘I never like doing that.'

And then on we went, skimming above this gigantic landscape with its sepia-toned mountains and valleys and ice. We crossed the Olympus Range,
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and the vast expanse of Mackay Glacier, before stopping here on the great sandstone cliffs of Battleship Promontory.

This was where Chris McKay found his green streaks of life, hidden inside the rocks. But the surfaces of these rocks hid another secret, on a much grander scale. George had brought me to see the carved signature of a massive, almost unimaginable, under-ice flood.

The pale sandstone cliff that we were standing on disappeared in a precipitous edge a few metres away. I craned my neck to see where the dry rock plunged down more than 3,000 feet.

‘I wouldn't like to go over this in a barrel,' I said.

‘Can you see?' George said eagerly. ‘Can you see how it's a waterfall? You see what's over the edge here? All the potholes at the bottom? And the ripples leading off from it? And all those conical hills down there? There's a big huge rippled terrain that goes all the way down to the sea. Shhhrrrrooom!'

And then he gave a satisfied sigh. ‘Spectacular isn't it? It looks like it's been bombed by B52s.'

It was certainly dramatic. And, yes, even to my inexpert eyes those bombed-out potholes were clear as day. ‘How do they form?' I asked. ‘From the water,' George said. ‘Water has come along those channels, right behind where the helicopter is, and it's spilled over and formed a plunge pool and another plunge pool and it just keeps on going. And there are thousands of them in these mountains.'

We walked to the other side of the cliff where the drop looked more like a scree slope, leading to yet more gigantic pits and potholes. ‘See how it looks like the Washington State scablands,' said George, ‘like Dry Falls, and the Grand Coulee.'

I hadn't seen the scablands but I knew about them. A vast area of Washington State in the US has terrain that baffled geologists for decades. It looks, apparently, as if some frenzied giant had scooped out chunks of land and flung them around. We now know that the scablands formed during the last ice age, when a finger of the ice sheet that covered much of Canada crept round and dammed a gigantic lake formed from meltwater. The lake built up and built up until eventually it burst through in a catastrophic flood. That, believed George, was more or less what happened here.

‘A landscape eroded by floods looks just like this. It has scooplike features all over, it has ripples in the top, it has lots of potholes and channel systems, it has coulees like this, it has conical hills like you see right at the end. None of those are typical of glaciated landscapes. This is completely different.'

‘OK,' I said. ‘I can see that it looks like it was made by water. But how do you know the water was under ice?'

‘We can trace these channels a long way,' George replied. ‘We've tracked individual ones with helicopters and they don't just go down. They go up over mountains that are two thousand metres high. Ice is the only explanation we have for how to force water up over a mountain range.'

So here it was. The dried-out cataract I was standing beside wasn't just an ex-Niagara. It was part of a network of waterfalls that were forced uphill by the weight of a massive overhead ice sheet, churning and rushing and carving out the landscape as they ran. This was Antarctica's hidden face, laid bare.

We had maybe half an hour of ground time here so the three of us headed off to the side of the scree slope and started to scramble down the ex-waterfall. As usual in Antarctica the distances were deceptive. These potholes were huge: a hundred feet deep, with sheer cylindrical sides. I could see now that they usually occurred where channels crossed; the confluence must have created huge whirlpools, focusing the water's energy and making it rip into the rock.

From the size of the channel, and of the lumps it ripped out of the rock, Dave Marchant has calculated that the water must have been travelling at up to 30 mph. And there must have been a lot of it. A few years ago people might have been sceptical, asking where the water could have come from. But we know now, of course, that there is plenty of water to be had beneath Antarctica's frozen exterior. It would only have taken a flood from one Lake Vostok, or perhaps one and a half, to carve out the channels scattered through these mountains.

There were other signs that there must have been ice overhead when the water ran here. In some places a channel stopped abruptly as if it had run out of steam. That could happen if racing, rushing water met a place where the ice was frozen to the bedrock. The water wouldn't be stopped; it would force open cracks in the ice and spurt up into the overhead glacier. In other places there were ‘hanging tributaries', where water had been pirated away from a channel, leaving it high and dry while the others eroded around it. It was one of the most spectacular landscapes I had ever seen.

On the way home, we flew over another dramatic signature of past flooding here: the Labyrinth, at the head of Wright Valley. To the south was the gleaming white edge of the polar plateau, held back for the most part by mountainous cliffs; just one wide strand of ice had managed to spill over the precipitous drop and spread its skirts to form Wright Upper Glacier. Long thin channels of ice radiated out from the sides of this glacier, like scars against the brown dolorite rock of the valley floor. And beyond those lay the Labyrinth itself, a tortuous landscape of yet more interlocking channels, the raised parts glowing golden brown in the midnight sun, the hollows in shadow. ‘Look down here,' George told me through the headphones, though I was already looking. ‘Can you see the cataracts and potholes? Just imagine the waterfalls cascading down.'

Dave Marchant has been working hard on the Labyrinth, tracing its complex interrelationships and peeling back its layers of history. He and George have carefully charted different parts of the channel systems in the Dry Valleys. They have worked out which cuts through what, separated out the older features from the younger, used volcanic ashes to date different layers and figure out what happened when. They agree that this landscape is incredibly old. There was probably a series of floods, but the last one took place somewhere between twelve and fourteen million years ago, and almost nothing has happened since.
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That fits the history of this mighty ice sheet. The cut-off came just about the time when the tundra was disappearing from the land, and the ice sheet was making its transition from one that was warm and wet and temperate to one that was frozen to the rock. It was also, probably, larger than it is today, over-reaching itself before settling back. And as parts of it froze to the bed, that could have been what dammed the shifting water beneath until it was powerful enough to burst out of its prison.

Floods like this wouldn't happen often, but, when they did, they would make themselves felt. Beyond carving out the rock, one of these mega floods wouldn't have raised global sea levels by much when it finally spilled into the Ross Sea. Perhaps it would have added a centimetre or two. But according to Dave, it might nonetheless have tweaked a sensitive spot when it comes to climate.

That's because the Ross Sea is one of the key parts of the global conveyor belt, an interdependent set of ocean currents that carries heat around the planet in a complex pattern that evens out some of the imbalances between the overheated tropics and the frozen poles. As sea ice forms here, the remaining water becomes saltier, and heavier, and sinks down to set the conveyor in motion. Throw in a sudden lens of freshwater on the top and you could jeopardise the whole thing. And though Dave can't prove it, he noticed that there were a few uncomfortable climate shifts that took place just around the time that the Dry Valley cataracts were being carved.

Luckily for us, this hasn't happened for at least twelve million years, and is unlikely to happen again any time soon. But there is one final twist to this story. Marine geologist John Anderson has found another Labyrinth-like feature in the ocean floor. And is it in a sensitive spot? John's underwater labyrinth is right in the middle of . . . Pine Island Bay, the place where, thanks in part to our own human ways of making and using energy, the warming water is eating away at the ice—and potentially opening the floodgates.

 

We don't know if or when there will be another mega flood around the coast of this mysterious continent, though researchers are learning more about it every day. Nor have we yet decided whether we humans will act to help the melting ice or hinder it. What we do know is that this icy landscape hasn't always been so listless and lifeless. And now it seems the warmth is coming back. Of course, there is a very long way to go before Antarctica will be steamy and tropical again, but that is the path we are currently taking.
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The Peninsula is already warming much more quickly than it should, and there are now the first signs that the rest of the continent is warming, too, with a signal that researchers have identified as both unnatural, and human.
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Thanks to the efforts of science we know a lot about how the continent is today. If you are reading this book in the northern summer, male emperor penguins are now huddling together somewhere in the lee of an ice cliff, taking turns to protect their fellows from the wind, taking care to keep each egg safely balanced on their feet, waiting for the return of the sunlight, and their mates, and the chance to eat again.

If you are reading in the northern winter, the sun is now shining over the continent. Snow petrels are jealously fighting for their rocky nests. Adélies are busily rushing through their short summer window for reproducing themselves, and scientists are just as busily making their pinprick marks on the vast continent, gleaning what they can from the ice.

And on the Peninsula, the ice is melting, the shelves weakening, while warming water laps perilously at the West Antarctic Ice Sheet's soft underside.

But what about the future? To some extent that's down to us. Though the whaling industry will never return on any scale, if some great new opportunity came up to exploit the continent, the treaty accords might well disintegrate, leaving everyone to revert to being very much for themselves.

This scenario is unlikely, though, because Antarctica itself would make it so very hard. Less than 1 per cent of the continent is free of ice. If oil grew scarce enough in the rest of the world that seeking it in Antarctica became attractive, it might be possible to drill offshore—though the icebergs would always be a threat. Onshore, the challenge would be all but insurmountable.

And even if you could drill here, the power of Antarctica to change people's mentalities might still prevail. It was in Antarctica that British scientists discovered the hole in our protective ozone layer, which led first to denial and confusion, but then to spectacular international cooperation as the chemicals doing the damage were globally banned and the hole began to recover.

Perhaps the steadying influence of this inhuman continent will help us all to tip the balance from smash and grab to human solidarity. I hope so. Because if we continue to pour out the gases that are warming our world, the melting will continue, and the seas will rise. If we stop, we can probably avert some or all of this danger. Our choice.

Two of the men the ice took to the edge, and who recorded their experience, discovered something important in the final analysis. When Richard Byrd lay sobbing in his bunk, and then wrote what he thought would be his last letter to his wife, he suddenly remembered the final entry in Scott's diary, which had been scrawled over the rest: ‘For God's sake, look after our people!' Byrd had thought about this before, but only intellectually. Now he understood completely. He wrote: ‘It seemed a pity that men must undergo a cataclysmic experience to perceive this simplest of truths.'
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Jake Speed, the South Pole winterer, said that, too. After I met him, he spent a season up in the north in Greenland, and found himself trapped out in a storm with no survival gear. Jake made it through three days of hell before he was rescued. He lost both legs and one arm. He says he survived by thinking of his new wife and family and friends.
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In the end, what really matters to us is our people.

So there it is. You go to the end of the Earth and you find . . . a mirror, a truism, something you should have known all along; or perhaps you did know it the way Richard Byrd knew it, intellectually. But now, after Antarctica, it's in your gut.

And when I think of all the things the people there told me, I realise that the other lessons that Antarctica has thrown up all point this same way: it is only when you are forced to rely overtly on the people around you—and people in far-off bases who you'll never meet—that you remember how fully we rely on each other back in the real world. It can take being in pure emptiness to remind you to let go of your hubris; and it can take being blocked by the power of nature to remind you how precarious our existence is and how tenuous and temporary our mastery.

Some find this frightening, but I take a strange kind of comfort from knowing that this patient and implacable continent doesn't care what we think or do. It will yield warnings if we seek them. We can avert human catastrophe if we act on them. But Antarctica itself is under no threat.