Antarctica is a bad place to be, for a research station. The first four Halley bases were swallowed up by a glacier, entombed forever in snow and ice. The fifth avoided that fate, but was instead abandoned in 2012 before it fell off an ice cliff.
Now the British Antarctic Survey (Bas) has announced that, 60 years after our scientists began working on the ice shelf, yet another Halley station is in trouble as the ice it is on threatens to break away into the ocean. This time they have a plan: they are going to ski it to safety.
Built on an ice shelf in the Weddell Sea, on the northwest corner of Antarctica, Halley has been housing researchers from Britain and other countries since the mid 1950s. Among their most significant work is the discovery of the hole in the ozone layer in the 1980s. The survey continues to look at atmospheric science and use its position directly below that hole to look at solar flares.
However, sitting atop 130m of ice brings difficulties. With Halley VI, Bas believed that it had at last designed a base able to cope with the twin challenges of being subsumed inside the glacier and falling off the end of it. It has now discovered a crack in the ice, growing at a few metres a day, that threatens to cast it adrift.
“The cracks are normal, part of nature, so we monitor them,” said Tim Stockings, Bas’s director of operations. “We’ve been looking at this one getting on two years. We noticed last year it is starting to grow.”
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Having been forced to relocate and rebuild the Halley station once every decade since the project began, the scientists were determined to find a better solution with the latest one, but the engineering problems are severe.
“The shelf accumulates snow at a rate of 1.5 to 2 metres per year. Over time that buries any fixed structure. The second issue is because ice shelves move, inevitably over a period of time the stations move. What we didn’t want to do this time was plonk down a station that ultimately we have to dismantle.”
So for Halley VI they ran a competition to design something better, and the winning solution was to make the base out of raised modules, all of which are on skis. This Antarctic summer, those skis will be used for the first time. At the moment the crack is 7km (4.3 miles) away, and because it has not yet spread across the shelf it can be outflanked.
If all goes to plan, each module in turn will be hitched to a large tractor and towed to safety. Why bother at all, though? Would it not be better just to build the base on rock?
“While in theory maybe it would be good to put the station somewhere else, our assessment is the quality of science might not be as good,” Mr Stockings said. “One of the beauties about the location is it sits right under all these amazing phenomena. You can look directly through the ozone hole and take incredible measurements over the long term. It’s where deep space meets the Earth.”