The British Antarctic Survey's (BAS) Halley VI Research Station can't seem to get a break. After being forced to move 23 km (14 mi) earlier this year because of a suddenly growing crevice in the Brunt Ice Shelf, the modular outpost is being abandoned for a second Antarctic winter due to the discovery of a second crack that is growing eastward. The 14-person winter crew will now be relocated to one of the other BAS Antarctic research stations or to the headquarters in Cambridge.

The sixth of the BAS Halley ice stations built since 1956 on the floating 150-m (492-ft) thick Brunt Ice Shelf, the £26 million (US$33 million) Halley VI base is a collection of eight brightly-colored futuristic modules mounted on telescopic legs to prevent them from being buried in drifting snow. These legs, in turn, have skis that allow the modules to be hooked together and pulled from one location to another.

The last move was carried out from November 2016 to March 2017 to place the station out of the path of a once-dormant ice chasm that had begun to grow after 35 years. Now the new site, Halley VIa, is threatened by a second chasm, called the Halloween crack, that was found last month and is moving in the direction of the station.

Graphic showing changes to the Brunt Ice Shelf and the location of Halley VI Research Station BAS

According to BAS, glaciologists are keeping a close watch on the ice shelf and the cracks using a network of sensors and satellites, but there are too many variables to predict what will happen in the near future. Though there isn't any immediate danger to Halley VI, to avoid mounting a rescue operation during the freezing darkness of the Antarctic winter the organization is erring on the side of caution.

"What we are witnessing is the power and unpredictability of Nature," says BAS director Dame Jane Francis. "The safety of our staff is our priority in these circumstances. Our Antarctic summer research operation will continue as planned, and we are confident of mounting a fast uplift of personnel should fracturing of the ice shelf occur. However, because access to the station by ship or aircraft is extremely difficult during the winter months of 24-hour darkness, extremely low temperatures, and the frozen sea, we will once again take the precaution of shutting down the station before the 2018 Antarctic winter (March – November) begins."

Because of these base evacuations, BAS is developing ways to relocate sensors and develop automated data capture technologies to make up for the lack of winter personnel.

Source: BAS