After being beaten to the south pole by the Norwegian Roald Amundsen in 1911, the British explorer Ernest Shackleton wanted to do one better—cross the entire Antarctic continent from sea to sea via the pole. But the doomed 1914 expedition would end before it could begin, with the Endurance becoming trapped and crushed by the ice, sinking to the bottom of the Weddell Sea. After camping on the ice for over three months and floundering to nearby but uninhabited Elephant Island, the crew undertook a daring 800-mile open-ocean voyage in lifeboats, navigating by the stars, finding refuge and eventually rescue on the sub-Antarctic island of South Georgia.
In 2016, a team of scientists from the British Antarctic Survey noticed something alarming. A massive crack was forming in the Larsen C ice shelf, already some six miles long. Using satellite thermal infrared imagery, they monitored the crack as it spread northward, eventually concluding that a significant portion of the shelf was about to give way. Finally, in June 2017, the largest iceberg on Earth, over 1000 feet thick and 2,200 square miles in area—larger than the state of Delaware—broke away and began to drift out to sea. The calving of the berg, dubbed A-68, was a colossal geological event. The news was heralded with much handwringing as the latest evidence that climate change is rapidly remaking the planet, causing unprecedented events to be taking place on unthinkable scales.
After drifting for three years, it was recently reported that A-68 is on a collision course with the island of South Georgia. Contrary to impressions, the islands near Antarctica are biological hot zones. The cool, nutrient-rich waters promote an explosion of tiny crustaceans called krill, one of the most abundant creatures on Earth, upon which a complex food web is based. Whales, fish, fur and elephant seals, penguins, and pelagic seabirds such as albatross, petrels, and gulls congregate in massive numbers, some traveling enormous distances to take advantage of the feast. They in turn attract predators such as orcas, leopard seals, and skuas.
Penguins in particular—adélies, chinstraps, kings, and emperors—find safe harbor on these islands. Most of what we know of penguins comes from observing them on land, where they are clumsy, if cute. But penguins spend the majority of their lives in the water, where they are much more difficult to observe. In her essay “White Lanterns”, Diane Ackerman makes the point that while considered “flightless”, underwater, penguins truly fly, hunting fish and darting around with ease at the flick of a wing. Their oily coat keeps dry their thick layer of down and blubber, and countercurrent exchange of blood keeps their feet warm, protecting a single egg from the ice.
Ackerman writes further about her trip to a South Georgia king penguin rookery:
“…our Zodiacs cut through thick curling waves onto a steep beach. For some reason there was the sound of harmonicas and, occasionally, distant oncoming trains. Turning, I saw a nearby hill seemingly squirming in the sunlight and automatically walked toward it. All at once it reeled into focus as a bustling, fidgeting, buzzing, clamorous, colossal king-penguin metropolis that sprawled for miles, pouring along the scimitar-shaped beach, through interfolding valleys, spilling down the hillsides. It was penguin heaven. The adults stood tall, with those splendid pairs of orange commas on their cheeks, a radiant sun-yellow blooming at their throats, and an apricot or lavender comet along each side of their bills. Stately, curious, they allowed me to sit down right among them. One slightly potbellied king, carrying an egg on its feet, ‘head-flagged’ with its mate, bobbing and sweeping heads like signalmen with flags, or shadow boxers. Then the female touched her bill to her brood patch—a vertical opening where she held the egg—tossed her head up, and rubbed her bill back and forth across her mates neck, as if to sharpen it on the whetstone of his desire. A neighbor bashed them both with its flippers and they screeched a rude reply.”
The presence of an iceberg the size of A-68 in the vicinity of South Georgia is enough to disrupt fish migration and the foraging habits of species like king penguins that rely on them. Already threatened by warming seas, entire populations would be forced to travel further for food, expending extra energy they might not be able to spare for themselves or their young. Migration to another site is possible, but any new area, should they find it, would be more prone to failure. The result of a direct collision would be worse, with ice blocking historic breeding grounds, or potentially scouring them away completely. Either way, it could be decades before the entire berg melts or breaks up.
Shackleton, on a subsequent expedition in 1922, died of a heart attack while anchored off South Georgia. It would be another 40 years before the first trans-Antarctic crossing was achieved. He will be remembered for many things, namely the hubris of trying to conquer a continent and the unimaginable ordeal of his expedition, but also the courage and heroism of that attempt, the “romantic” era of exploration at its best. It strikes me that climate change is much the same, reflecting our own hubris and dealing out the consequences of our ill-fated exploits. The old and new, converging in a single moment. Science itself changing and evolving, tracking the motions and moods of the Earth.
Update: A-68 is officially gone, broken up into many pieces and melted into the southern ocean. It did not come to ground off of South Georgia, as was feared.
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