Ice crack forces Antarctic research station to close for second time

A widening crack in the Antarctic ice shelf has forced a British mobile research station to close for a second time to avoid the risk of drifting.

Two ice cracks threaten Antarctic research station.

The British Antarctic Survey (BAS) announced last week that it will close its Halley VI station on the Brunt Ice Shelf in the Weddell Sea during the upcoming southern polar winter from March to November 2018, shortly after the summer operating period ends, according to Live Science.

This is the second winter in a row that Halley Vi station has had to close because of the risk of being trapped between two growing cracks in the 150-meter-thick floating ice shelf.

The most recent assessment by glaciologists shows that the rate of expansion of a deep crack in the ice about 20 km from Halley VI station has increased during the 2017 winter, and a second crack called Halloween that appeared north of the station in October 2016 is also continuing to extend eastward.

BAS said Halley VI could be safely evacuated if the cracks grew large enough to separate from the main ice shelf, a phenomenon known as a “breaching event.” However, faced with the prospect of a forced evacuation amid the harsh, dark weather and icy waters of the Antarctic winter, BAS opted to close the station as a precaution, according to BAS communications director Athena Dinar.

"The spread of both cracks during the last Antarctic winter raises concerns. If BAS staff were to spend the winter at the station and a collapse event occurred, there would be no aircraft or ships in the vicinity to assist in the rescue," Dinar said.

Halley VI Station always has a team of 14 scientists and technicians staying over the winter. They continue to collect data from the experimental equipment and operate the station's equipment during the harsh winter storms of Antarctica.

Staff scheduled to spend the winter at Halley VI in 2018 will be redeployed to other BAS Antarctic research stations or returned to the UK.

"We are witnessing the power and unpredictability of Nature. The safety of our staff is our top priority in these circumstances. Our Antarctic summer research period will continue as planned," said Jane Francis, director of BAS.

Before 2012, the deep rift southwest of Halley VI had remained the same for at least 35 years. But the rift has since widened, growing by 1.7 kilometers (1.1 miles) each year. After the Halloween rift appeared north of the station in October 2016, measuring 22 kilometers (14 miles) long, BAS decided to move Halley VI to a new location on the ice shelf where it was less likely to experience a collapse event. The Halloween rift has grown rapidly since it first appeared, and is now 37 kilometers (23 miles) long, BAS reports.

Halley VI’s capsules are equipped with skis and are designed to be dragged along the ice if they need to be relocated. In early January, BAS began towing Halley VI’s eight 10-ton capsules to a new site about 14 miles (23 kilometers) away.

Halley VI will operate normally at its new location on the Brunt Ice Shelf for four months during the summer before it begins to close in March 2018. Technicians are currently thawing out the facility after eight months of inactivity, preparing to receive 73 BAS staff who will arrive in Antarctica this week.

According to VNE