Scientists just drilled the deepest hole ever in western Antarctica, going 2 kilometers down through the ice to study how it's melting
- A team of British scientists has successfully drilled the deepest hole ever in Western Antarctica.
- The hole is about 2.1 kilometers deep — about four times taller than the Sears Tower.
- It took an 11-person team from the British Antarctic Survey 63 hours of continuous drilling to reach that depth.
- They brought sediment samples up to the surface, which they hope will yield new information about how quickly ice is melting beneath the West Antarctic ice sheet.
After nearly three days of round-the-clock drilling in temperatures as cold as minus 22 degrees Fahrenheit, a team of scientists has drilled the deepest hole ever seen in western Antarctica.
On January 8, 2019, a British Antarctic Survey team called BEAMISH (short for Bed Access, Monitoring and Ice Sheet History) broke through West Antarctica's Rutford Ice Stream, reaching a depth of 2,152 meters (7,060 feet).
The 11 BEAMISH scientists used a high-pressure hose to shoot 194-degree-Fahrenheit water at the ice, thereby boring a hole down to the sediment below.
It's the deepest hole ever drilled in the area, though deeper ones have been drilled in Eastern Antarctica. (Russian researchers reached depths of 2.4 kilometers under the continent's eastern ice sheet in 2012, and the IceCube Neutrino Observatory at the South Pole boasts a similarly deep hole.)
The team pulled up sediment samples to analyze, and also took measurements of how much the ice's shape has changed as well as the temperature and water pressure at those depths.
The achievement was some 20 years in the making. In 2004, BEAMISH attempted to drill a similar hole without success.
“I have waited for this moment for a long time and am delighted that we’ve finally achieved our goal," lead scientist Andy Smith from the British Antarctic Survey said in a statement.
Hot-water drilling isn't easy
The challenge of drilling in regions like this one — where temperatures hover around -30 degrees Celsius (-22 degrees Fahrenheit) — is that the hole constantly refreezes.
“There is a limited time window of about 24 hours where the hole is large enough to deploy instruments,” Keith Makinson, a physical oceanographer at the British Antarctic Survey, told Newsweek. “After two or three days, the hole has fully refrozen. This makes the round the clock drilling and science work very time pressured.”
That also means scientists must use the hot-water drill to periodically restore the hole to its original diameter. The largest parts of the drill (which they had to assemble piece by piece) weigh upwards of 15,400 pounds.
Clues about Antarctica's future
The BEAMISH team hopes their work can help make sense of western Antarctica's glacial history, and reveal how polar ice sheet melt may impact sea-level rise.
"There are gaps in our knowledge of what’s happening in West Antarctica and by studying the area where the ice sits on soft sediment we can understand better how this region may change in the future and contribute to global sea-level rise,” Smith said
The Rutford Ice Stream, where they drilled, carries melting ice from below the western Antarctic ice sheet out to the ocean. That's why studying this part of the continent is crucial in order to understand the effects of climate change.
“We know that warmer ocean waters are eroding many of West Antarctica’s glaciers," Makinson said. "What we’re trying to understand is how slippery the sediment underneath these glaciers is, and therefore how quickly they might flow off the continent into the sea."
The speed of that flow has consequences for sea-level rise. If all of Antarctica's ice sheet were to melt, it would result in a global sea-level rise of 180 feet. If both Antarctica and Greenland's ice sheets melted, the seas would rise by more than 200 feet. That would completely submerge Florida.
The team plans to continue their field work until mid-February. They drilled another hole on January 22 and have plans for a third a few kilometers away.
Antarctic drilling projects like this one, as well as the SALSA project that found tiny animal carcasses in a subglacial lake, are imperative to mapping out the continent's potential melting timeline — a scenario that could have consequences for the rest of the globe.
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Contributer : Tech Insider https://read.bi/2MyYSBr
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