Antarctica (41 page)

The men on shore, meanwhile, were mystified. How was a steam tug coming to their rescue, and a Chilean one at that? But then the
Yelcho
lowered a boat. When Wild saw the unmistakable figure of Shackleton in its bow he nearly cried.

Within an hour all the men were off Elephant Island, heading for home. ‘I have done it,' Shackleton wrote to his wife on arriving back at Punta Arenas. ‘Damn the Admiralty . . . not a life lost and we have been through Hell.'
³²

Shackleton's expedition marked the end of the heroic age. His men had left a world of Edwardian heroism and endeavour and returned to the insanity of world war, and the Somme. But though his hopes had been crushed by the ice of the Weddell Sea, Shackleton had once again made his Antarctic mark.

Apsley Cherry-Garrard, one of Scott's most loyal followers, wrote this about the merits of Antarctica's three most famous heroes: ‘For a joint scientific and geographical piece of organization, give me Scott . . . for a dash to the Pole and nothing else, Amundsen: and if I am in the devil of a hole and want to get out of it, give me Shackleton every time.'
³³

And before he left for home, Shackleton wrote a poem in the visitor's book of one of the local dignitaries that captures better than most the madness that keeps people returning to the ice even today:

 

We were the fools who could not rest
In the dull earth we left behind
But burned with passion for the South
And drank strange frenzy from its wind
The world where wise men sit at ease
Fades from our unregretful eyes
And thus across unchartered seas
We stagger on our enterprise.
³⁴

 

Following his work on Lallemand Fjord, Gene Domack was satisfied that his model was working. He could study the mud beneath a former ice shelf and learn if the shelf had a habit of breaking up, or if the recent events truly ought to be alarming.

His new target was Larsen B, the next shelf on the list for potential break-up. It was much bigger than the other ones that had recently retreated—more than 1,000 square miles in area, and 700 feet thick. So far, it had also held firm. But lately it had been shedding some large icebergs. Gene planned to go to the place where one had broken off, and examine the mud beneath.

The ice might yet hold them back. The year after the
Palmer
worked Lallemand Fjord, a British team led by glaciologist Carol Pudsey from the British Antarctic Survey had tried to get down to Larsen B, but the pack had thwarted them. Instead they made it only as far as the ex-Prince Gustav Ice Shelf at the tip of the Peninsula. They collected mud from where the ice used to be and found unmistakable signs that this shelf had disappeared before, a few thousand years ago. It seemed that it came and went perfectly naturally. The collapse of the Prince Gustav, at least, could not be put down to human climate change.
³⁵

That sounded like good news. But the Prince Gustav Shelf was both small and very far north. It wasn't that surprising that it might come and go. Larsen B, on the other hand, was much larger, and more southerly. If that, too, showed signs of previous collapse we humans were probably off the hook as far as the Peninsula warming was concerned. But if it didn't, that could be very bad news.

Gene, Amy and the team hit lucky. Aboard the
Nathaniel B. Palmer
, they found enough gaps in the pack ice to edge their way south into the Weddell Sea. They passed Elephant Island, and James Ross Island and many of the landmarks that Shackleton had noted as he and his men drifted helplessly by on their Patience camp. In January 2002 they sailed right up to the face of the Larsen B ice shelf, to where a berg had broken off in 1995, and began their coring and sampling. They were hoping to find the same sort of signals they had seen at Lallemand Fjord—dull grey mud when the ice shelf had been overhead, delivering its ground-up rock to swamp the seafloor with grit, and green mud if it had ever retreated in the past, and left open water for green living things to flourish and then sink when they died. Gene and his team cored and collected and stored and headed back, satisfied, across Drake Passage to Punta Arenas.

Nobody expected what happened next. In February, just a few weeks after Gene and the
Palmer
left the area, Larsen B unexpectedly exploded. It became suddenly shot through with cracks and the ice turned to rubble. Newly formed icebergs jostled to escape. They lurched on to their sides, and crashed into each other and rode their way out of the newly formed bay in a gigantic plume. By the beginning of March, 500 million tonnes of ice, an area bigger than the US state of Rhode Island, had shattered.
³⁶

The opening scenes of the Hollywood climate disaster movie
The Day After Tomorrow
are modelled on the break-up of Larsen B. They show the hero working in Antarctica, camping on a floating shelf of ice, drilling ice cores through its surface. The first sign of impending doom comes when the ice shelf cracks, right across the research site. In trying to save his precious ice cores, our hero only just survives.

Most of the movie was ludicrously overplayed from a scientific point of view. The hurricanes and tornadoes and tidal waves were wildly exaggerated for blockbuster effect. But not the break-up of Larsen B. If our hero had been on the real ice shelf as it shattered, he would have had to run for his life. Larsen B's catastrophic collapse could represent the first time ever that reality was too much even for a Hollywood disaster.

Gene and the rest of the world's ice scientists were stunned. They had thought Larsen B might begin to break up some time soon, but not like this, so fast, so furiously. Could this be something new, a terrible effect of recent warming? Or were there any reassuring signs that it had happened before?

Hastily Gene sorted through his newly retrieved samples to see what the mud had to say. And what he found was as shocking as the Larsen B's almighty breakdown. As far back as the record could show him, all the way to the end of the last ice age 10,000 years ago, the ice shelf had been fully intact.
³⁷

The spectacular collapse of Larsen B was completely new.

This was deeply troubling news. It seemed to confirm what many meteorologists suspected—that the warming of the Peninsula really is down to our activity.
³⁸
In the disappearing ice shelf, Gene had found concrete evidence that humans are touching the Peninsula with more than just churches and schools, or even harpoons. Our entire way of life, the cars we drive, the electricity we make, the forests we clear, all are now apparently making their mark on the Antarctic Peninsula.

There was one shred of comfort. Floating ice already displaces water, so when ice shelves disintegrate they don't make sea levels rise. But they now looked like a serious warning sign, a shot across our bows. ‘The Peninsula ice shelves really are the canary in the mine,' Gene said. ‘And if the canary goes, you have to be worried.'

What's more, the shelves seem to have an important effect as gigantic buttresses, holding the land ice back and preventing it from sliding into the sea. There are already signs that some of the glaciers that used to feed Larsen B, freed from its restraining influence, are now speeding up.
³⁹
If the same thing happened with the monster ice shelves, and the glaciers they dam, spectacular rises in sea level could be with us sooner than anyone has imagined.

And that's the biggest worry of all. Antarctica's land-based ice sheets contain enough ice to swamp our puny, shore-hugging civilisations. If the Peninsula is showing this response to climate change, could the ice sheets themselves be next?

7

One is old and cold and settled in its ways. The other is smaller but nimbler, moving quickly, connected to the oceans, looking—perhaps—to change. These are Antarctica's two great ice sheets, joined, like mismatched butterfly wings, by a backbone of mostly buried mountains running the length of the continent.

On the eastern side is the East Antarctic Ice Sheet, by far the larger of the two, a mighty behemoth that contains more than 80 per cent of all the ice on Earth. Though its average thickness is more than a mile, most of its base still rests safely on high ground and most of its ice creeps only sluggishly from the centre to the sea. It has been around for tens of millions of years.

Since its coastline tracks the Indian and Atlantic Oceans, the eastern ice sheet is relatively easy to reach by ship or plane from New Zealand, Australia, South Africa and the tip of South America, and its edges are dotted with scientific bases. Even its harsh interior is the home of the American South Pole Station, Russia's Vostok, the French-Italian Concordia.

On the west, however there is . . . nothing. The coastline of the West Antarctic Ice Sheet faces the broad, empty expanse of the Pacific Ocean. No nation can reach it simply by sailing south and it has not one single permanent scientific station. Most of the ice sheet lies beyond the normal reach of any existing Antarctic operations. The west of Antarctica is truly Earth's final frontier.

Five times smaller than its eastern sibling, it is also much more vulnerable to change. The rock on which the West Antarctic Ice Sheet rests isn't high like the east. Instead, almost all of it lies below sea level, and some is ten thousand feet deep. So deep, in fact, that if it weren't for the ice there would be nothing in the west but ocean, and a smattering of small island archipelagos.

The only reason the western ice hasn't already floated away is that it's currently thick enough to keep the sea at bay. But if the glaciers that drain it speed up, and the ice sheet thins, the sea could reclaim its ground, floating and shattering the ice in a catastrophic meltdown that would be felt in rising sea levels the world over.
¹

There is plenty of evidence in Antarctica's climate records that this has happened before, when temperatures were naturally higher than they are today. Nobody knows exactly when the last collapse happened. It could have been as recently as a hundred thousand years ago—the last time the Earth was between ice ages, as we are today. But it was certainly some time in the last million years, the ‘recent past' on the long timescale of ice.
²

Scientists have known this for decades. With temperatures now rising for reasons that appear to go far beyond natural fluctuations, the question now exercising them is: how soon will it happen again? There are already signs that, although the east looks more or less in balance, the west is now seriously losing its ice.
³
The high plateau of the east is where researchers look into the past: up into space to the origins of the universe, or down into the ice through climate layers of history. The west is where they look to our future.

 

West Antarctica is a tough place to visit. My one and only trip there nearly didn't happen at all.

The western ice sheet divides neatly into thirds, each region acting as a separate giant conduit through which ice drains from the interior out into the sea. I wanted to get to one of these three conduits. If changes were happening anywhere, this was where to find them.

Two of the three were more or less out of bounds: one, the sector that fed the Ronne Ice Shelf, was on the far side of the continent, studied mainly by the British and Germans who did not have the spare logistics capacity to take non-essential personnel so far out into the field; one, which spilled into the Amundsen Sea right in the middle of the ice sheet, was far from everyone's logistics, shrouded in perpetual fog and studied by nobody.

But the remaining third might be reachable—just. The Siple Coast sector was just a few hours' flight from McMurdo by Hercules plane, and American researchers had been studying it for decades. There, five massive glaciers called ice streams were spilling into the far edge of the Ross Ice Shelf. They were thicker and wider and moved faster than almost any other ice on Earth. And a team from Caltech was currently drilling through one of them, hoping to reach the engine room that is driving the glacier from below.

It was remote, of course, and even the National Science Foundation's extensive logistics were stretched when they reached out that far. But still, all was looking promising until disaster struck during the camp set-up. Two months before I was due to go, the Herc that was carrying the scientists and their support team broke into a crevasse while taxiing on the snow. It didn't seem too dramatic at first; the plane just tilted from one side to the other, then stopped. But the pilots quickly realised they had opened up a snow bridge and one of the plane's skis had lurched into a hole that was about three metres wide, and very dark and deep.

The passengers had to climb out through the escape hatch on the roof, roped together by a mountaineer who was still fuming that she had not been allowed on the flight deck to advise the pilots. A Twin Otter came in to take the science team home and a new team moved in, with snow dozers and giant air bags and heavy lifting equipment.