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Posted by on Nov 3, 2017 in Science tech, Tech Trending | 0 comments

Scientists Start to Defrost Britain’s Very Frozen Halley VI Antarctic Base

Scientists Start to Defrost Britain’s Very Frozen Halley VI Antarctic Base

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Sometime in the next few days, a DHC-6 Twin Otter ski plane will circle the British Halley VI Antarctic base, look for the landing strip, and touch down on a floating ice shelf.

Two plumbers, an electrician, and an engineer will grab their gear, check their satphone, and wave goodbye to the pilot. For the next few weeks, the team will try to jumpstart a base that has been closed for the past eight months. Normally, the streamlined research structure would face the brutal Antarctic winter with 14 hardy souls to keep valuable scientific equipment warm and running. But British science officials shut down the remote outpost last March because of a 300-foot wide crack in the Brunt Ice Sheet creeping toward Halley about nine miles away.

Now, for the first time in modern Antarctic history, a team will attempt to restart equipment and generators that have been sitting in temperatures down to -67° Fahrenheit. They hope it will turn back on. But it might not.

Alamy

“We know it’s standing, we know it’s not buried in snow,” said David Vaughan, science director for the British Antarctic Survey, which operates the base. “We might find some snow inside, and there is always the possibility that windows have been broken.”

Vaughan and others at the Cambridge-based research unit have been scanning NASA satellite imagery to keep an eye on Halley VI, which was built on a hydraulic leg and ski system to raise up above the annual snowfall. Without jacking it up every year, snow would bury the station. Over time, it would become part of the moving ice sheet, carried to the edge of the ice shelf and dumped into the ocean.

It’s happened before: The UK has operated a research station on the 500-foot-thick Brunt Ice Shelf since the late 1950s, and Halley bases I to V were either demolished or slowly drifted out to sea on icebergs. But Vaughan says he’s not ready to abandon Halley VI.

“It’s something we will be looking at year by year,” Vaughan says. Halley VI is actually threatened by two cracks: Chasm 1 and the “Halloween crack.” British glaciologists say the northern movement of the chasm, which had been dormant for 35 years, has accelerated in the last seven months. Meanwhile, the Halloween crack continues to move east toward the base. “The cracks are forming, until they go all the way and produce the icebergs and drift away,” says Vaughan. Tractors can pull the base to a new location, but the British Antarctic Survey already pulled that move in February—and they’re hoping not to resort to it again too soon.

Glaciologists are also worried about the rapid movement of Pine Island and Thwaite’s Glaciers in West Antarctica and July’s calving of a massive iceberg from the Larsen C ice shelf on the Antarctic Peninsula. But the Brunt ice shelf is just doing its normal cracking as it reaches the ocean—at least for now, according to Vaughan.

Once the team arrives, they’ll hustle to turn on the generators, which run on aviation turbine fuel that can be stored down to to -53°F. These machines are the lifeblood for the station, providing heat and electric power. First, the crew will turn on the small generators—they’re more reliable in extreme cold—and work their way up to the larger ones.

Then they’ll start a-fixing. Camping out in a shipping container adjacent to the larger base, the four British MacGyvers will check on every component in the base for damage from the frigid temperatures. The last people to leave in March 2017 prepared the station as best they could. “We drained the water system and all the sewage,” says Vaughan. “We took out all of the scientific equipment and brought it back to the UK.” Anything with a disc drive was removed; while computers like cool ambient temperatures to dissipate the heat they generate, most electronic parts aren’t designed to survive -67°F weather.

But they still had to leave a lot behind. Wiring, fuel lines and everything else inside the base is usually kept warm. Different materials—plastics, rubber, metal alloys—all have unique thermal characteristics that make them expand and contract at different temperatures, according to Uwe Nixdorf, who heads up Germany’s Antarctic logistics efforts at the Alfred Wegener Institute. “They are designed and built to be OK in normal temperatures, but maybe not in temperatures that are below -40°C,” Nixdorf said from his office in Bremerhaven. “They could shrink in different speeds and amounts. Maybe cracks are forming.”

With some British luck, the four men will get the station into shape for the second wave of base workers, who arrive in December. Halley houses up to 80 scientists and support staff during the Antarctic summer, which lasts from November to March, then about 10 to 14 during the winter. They will have only a few months to get the science projects back online—studying space weather, meteorology, and atmospheric sciences. Data collected from Halley led to the British discovery in 1985 of a hole in the Earth’s ozone layer above Antarctica, and recent measurements indicated that the ozone hole may be recovering and about to close.

But with the 2017 closure, and another base closure planned for the 2018 winter season, that continuous 60 year-old dataset will be interrupted. To avoid future snags, BAS engineers and researchers are trying to automate more of the station’s data collection devices. Wind turbines may be an answer, but they are often blown over by powerful Antarctic gusts.

In December, the relief crew will be testing a new prototype micro-turbine generator that could provide enough power to keep some instruments running all winter. “It’s like a small jet engine in a box,” Vaughan says. It’s a long shot; they’ll have to figure out a way to get rid of the water vapor covers the exhaust with ice, and nobody has ever run such a device remotely for eight months. But don’t bet against the British in Antarctica.

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