Rescued scientists bring back a warning about changes at the southern ice cap
The voyage was meant to retrace the steps of Douglas Mawson, the great polar explorer and scientist who led the Australasian Antarctic Expedition of 1911. What happened instead captured the world’s attention, something none of the scientists, journalists and paying public aboard could have foreseen.
The Akademik Shokalskiy got stuck in ice on Christmas Day 2013 only two weeks after leaving New Zealand. A rescue mission swung into operation. Chinese, French and Australian icebreakers hurried to the scene only to be defeated by the ice floes.
With no icebreaker able to smash way through, a Chinese helicopter, Xue Ying (Snow Eagle), rose into the air for the first of five flights to ferry passengers from the stricken ship. A core crew remained behind to sail vessel home once conditions allowed.
Media interest in the expedition faded after the rescue, but in the year since expedition leader Chris Turney and his team have been busy. Scientific samples and measurements from the voyage are being turned into research papers that reveal striking changes at the southern ice cap. And rather than feeling discouraged about expeditions that are funded by paying passengers, Mr. Turney is more enthusiastic than ever.
“Once we got back home and made sure everyone was all right, we got on with working up the data and getting a whole load of papers ready for submission,” he said.
Like the rescue mission, this involved plenty of waiting. “It took nearly six months to get all the samples through quarantine.” Simple observations told unhappy stories. Trawls of water reeled in hauls of plastic rubbish, now seemingly ubiquitous in the world’s oceans. On land, counts of Adelie penguins revealed the population had slumped near Mawson’s huts in Commonwealth Bay in East Antarctica. The birds are now commuting 40 miles to get food for their young.
“Another 10 years there probably won’t be many left,” said Mr. Turney. The numbers of skuas seemed to have fallen too.
Commonwealth Bay has experienced substantial changes in recent years. In summertime fierce katabatic winds blow off the continent and chill the surrounding surface water to freezing point. The freshly created ice blows out to sea, as if on a production line. But the freezing process leaves behind cold, dense water that sinks to the sea floor, forming part of an oceanic current that drives circulation on a global scale.
The ocean circulation at Commonwealth Bay was disrupted in 2010 after an enormous iceberg, B09B, arrived. The 30 mile—long slab of ice smashed into the nearby Mertz glacier tongue and grounded itself at the entrance to the bay. That blocked the exit for fresh sea ice. As the ice built up, the ocean conveyor system partially closed down.
Such changes were bound to impact on life beneath the ice. Scientists inspected ecosystems on the sea floor. “You see this remarkable transition with the expansion of sea ice. A lot of kelp and other life on the seabed is dead or dying. We’re seeing instead much of the deeper flora and fauna, as they come up from the deeper seabed because there’s an ecological niche to be filled,” said Mr. Turney. The shift in the ecosystem is expected to have impacts all the way up the food chain.