British Antarctic staff are being pulled out of their space-age Halley base in March for safety reasons.
British Antarctic Survey's Halley research station is already being moved, but staff will be pulled out for the winter. Photo: British Antarctic Survey
The highly unusual move is because the Brunt Ice Shelf on which the research station sits has developed a big new crack.
British Antarctic Survey (BAS) officials say neither staff nor the base are in any immediate danger but believe it would be prudent to withdraw while the situation is assessed.
The plan would be to go back once the Antarctic winter is over, in November.
Halley station comprises a series of hi-tech pods mounted on hydraulic legs and skis so they can be moved periodically further inland, to get away from the shelf edge where icebergs are calved into the ocean.
BAS is already relocating the station and the last pod is in the final stage of being shifted 23km to the new site. The move was needed because by a chasm had opened up in the shelf and which threatened to cut off Halley.
But this huge fissure, to the west of the station, is not the cause of the temporary closure.
Another break in the ice some 17km to the north and east of the new base position, has prompted the evacuation as a precautionary measure.
It has been dubbed the "Halloween Crack" because it was discovered on 31 October.
The organisation does not believe the ice shelf is about to experience a major calving event, but makes the point that if something were to happen it would be very difficult to react in the depths of an Antarctic winter. Scientists were unable to predict with certainty what would happen to the ice shelf during the winter.
"What we've decided is that given the unpredictability, combined with our inability to do anything about it in winter - no aircraft in the continent, it's dark, it's very cold; all those kinds of issues - then actually the prudent thing to do is withdraw our staff, close the station down in a controlled manner and then go back in next summer," BAS director of operations Captain Tim Stockings said.
Seven of the eight Halley modules have already been towed to the new site. Photo: British Antarctic Survey
Halley gathers important weather and climate data, and it played a critical role in the research that identified the ozone "hole" in 1985.
In recent years, it has also become a major centre for studying solar activity and the impacts it can have on Earth.
Just under 20 permanent staff live at Halley. In winter, they would watch over experiments. BAS now has to decide if any of those experiments can be left running autonomously, or whether it is better to just shut everything down.
Scientists have placed sensors on either side of the more than 40km-long Halloween Crack to monitor its status.
"Obviously, we'll seek to get out of those whatever we can; we'll also be using satellite imagery over the winter as well. Then, next season we'll send a team in to re-open the station, verify the measurements from our instruments and take the situation from there," Captain Stockings said.
"But I should say - we are committed to our presence in that part of the British Antarctic Territory and to the science we do there."
- BBC
