Sunday, November 21, 1999

Esprit de ‘core’: Teamwork takes Cape Roberts Project to new depths

Published in the Antarctic Sun

It’s the deepest bedrock hole in Antarctica. When the drilling at Cape Roberts stopped for the season on Thursday the hole was 3,084 feet deep—more than 650 feet farther than the previous record.

The two drillers, Malcolm MacDonald and Frank Tansey, took turns being the most important men in the Cape Roberts Project: the men who made sure the core kept coming up out of the hole and into the hands of climate researchers.

The drillers, though, couldn’t do anything without a lot of help of all kinds. The 40-person support and science team at Cape Roberts works around the clock, which makes for some odd situations.

“It seems a bit strange to see people in here having a beer at 8:30 in the morning, but it’s their night time,” said Colleen Clarke, who runs the camp during the day. Pat Cooper, the drill site manager, has been working in Antarctica since the early 1980s.

“The ‘Antarctic factor’ down here has a lot of influence on our drilling,” Cooper said.

Among the challenges this year was an April storm, which broke out some of the sea ice near where the drill site was planned to go. In August, a team flew down to check out the area and set up the camp.

“We didn’t really know for sure what was happening until we got down here at Winfly,” Cooper said.

But things looked good, and they decided to drill this year.

Now the project involves over 60 researchers and support staff. “It’s a mix of technology and science objectives,” said Peter Barrett, a member of the project’s management team.

A 60-ton drill rig sits on the sea ice, supported by the strength of the 8-foot-thick ice and under-ice balloons, which give an additional 11 tons of lift.

A 5-inch pipe, called the sea riser, provides the conduit in which the drill passes through the 980-foot-deep sea water. It must be freestanding and self-supporting to work properly. Suspending it from the sea ice only forces the ice to support more weight.

“It has to be totally independent of the systems up here,” Cooper said.

But it is impossible to stand a 980-foot-long 5-inch pipe on its end without help from above. The pipe is sunk 30 feet into the sea floor and is supported at the middle and the top by air bladders which pull up on the pipe to maintain the pipe’s rigidity and prevent it from bending or buckling too much.

They also have to deal with the movement of the sea ice itself. Under current conditions, the ice can move nearly 60 feet in any one direction before the angle of the drilling equipment will prevent it from working properly.

“To date we have moved off 6 meters (20 feet) from where we spotted in,” Cooper said.

The project has had the same drill crew for three years, which has made things easier every year, according to science coordinator Peter Webb.

“We’ve had amazing continuity,” Cooper said. “We’re a bit of a family, really, the old Cape Roberts team.”

When the core comes out of the hole, it begins a journey which will move it faster and further than ever before in its 40-million-year history.

It is removed from the core pipe and goes to the lab at the drill site for preliminary examination.
The core is examined, scanned, tested for physical properties, and split into an archive half, stored safely for the future, and a working half, from which samples will be taken at Crary Lab.

The working half is scanned again before the core goes on the helicopter to the camp and Crary. At $10,000 per yard of core, it’s worth a little extra time to photograph and scan everything in case of a helicopter accident or other disaster.

Some samples of the core are extracted at the drill site lab, to be used to determine more about the characteristics of the rocks being drilled, as well as to attempt to approximate an age for the rock layer.

The research is not just on the core itself, though. Some researchers are using the availability of a deep hole through many layers of rock to study the rock in situ.

Christian Buecker is one of these scientists. He does what is called “down-hole logging,” sending instruments down the hole to collect data about the rock around the hole, at intervals of a tenth of an inch.

The logging process takes a long time; 12 instruments run one at a time, at a speed of between three and 33 feet per minute, through about 1,150 feet of hole at a stretch. At the end of the last
logging run, Buecker had been awake for 44 of the previous 50 hours.

“We are looking for the physical and chemical properties,” Buecker said.

The data gathered helps them understand the core better, as well as the surrounding rock.

“It partly confirms our information and gives us new information about the structure,” Buecker said.

Among other things, Buecker has learned that the temperature at 2,500 feet down the hole (below the sea floor) is 68 F. It increases as they get closer to the center of the Earth.

But 3,084 feet is as close as the project will get to the Earth’s center. But in terms of both science and technology, this is not the end.

Camp manager Jim Cowrie has put in a proposal to the member countries of the Cape Roberts Project to set up a consortium of Antarctic drillers and researchers who use drilling as a method of gathering data.

Barrett is also making an effort to expand beyond just this three-year project. He hopes eventually to be able to drill through the center of the ice sheet, perhaps at Vostok, and into the
sediment below, to see what was happening in the center of Antarctica.

But even this work, in which the margins of the ice sheet are being studied, has been fruitful.

“It’s advanced the technology and advanced the science,” Barrett said. “We actually think this is fun.”