Pine Island Glacier
Scientists prepare for difficult trip to Antarctica's most dynamic region
Posted July 10, 2009
More than 18 months ago, Robert Bindschadler became the first person to stand on the crevasse-ridden ice shelf fed by Pine Island Glacier, the fastest moving river of ice in Antarctica.
It turned out to be the first and last flight to the floating sheet of ice for that field season.
Bindschadler, along with his colleague David Holland, had been on a reconnaissance mission to this windswept, barren spot. Their plan was to survey the location for a future field camp where they could safely work on the ice shelf, which is thinning rapidly along with the glacier. Below the hundreds-meter-thick ice, the ocean is melting the shelf, allowing the glacier to accelerate its charge into the Amundsen Sea.
Nearly a third of the ice in West Antarctica drains through the region. Were it to all pour out in a catastrophic uncorking, sea level would rise more than a meter, enough to drown coastal areas from Florida to Bangladesh. In the immediate future — over the next century — scientists are sure Pine Island Glacier, referred to as PIG, will contribute significantly to sea level rise. Just how much remains the big question drawing them to that remote corner of the continent.
“We’re going out to this difficult-to-get-to, hard-to-operate-in area because that’s where dramatic things are happening,” explained Bindschadler, chief scientist of the Hydrospheric and Biospheric Sciences Laboratory at NASA’s Goddard Space Flight Center.
“This is where satellite observations are setting off sirens and raising red flags,” added Bindschadler, the principal investigator for the multi-disciplinary project, which is also part of the International Polar Year (IPY) program. “This is where all the action is taking place. We don’t have any choice in the matter. We have to go there.”
Despite landing on the ice shelf with a ski-equipped Twin Otter, the surface proved to be too hard and too rough to ensure a safe series of repeated aircraft landings. The National Science Foundation-funded project to study how the ocean and ice interact seemed over almost before it began.
“It was a crushing blow,” Bindschadler said. “On the fly we had to make up a different field program, at least for that season.”
Convinced it would still be possible to work on the ice shelf in the future, and motivated by the unanswered scientific questions, the researchers installed an automatic weather station (AWS) near the glacier to monitor the weather and two GPS units on ice streams feeding Pine Island Glacier to track the speed of the ice toward the ocean.
More than a year later, the AWS still works, shutting down only occasionally in the winter when intense storms cause icing to block the satellite communications. The information it has sent via Iridium satellites confirms that this part of West Antarctica is a common target of storms, with an annual snow accumulation of about a meter.
“That’s the beginning of getting important, meaningful data,” noted Holland, a co-principal investigator and director of the Center for Atmosphere Ocean Science at New York University.
The road back to PIG
The road back to PIG for Bindschadler, Holland and their colleagues goes through Byrd — a former field camp and research station of the U.S. Antarctic Program (USAP). This season the National Science Foundation (NSF) will build a new deep-field camp at 80°S and 119°W to support a number of projects in West Antarctica, including the eventual return trip to Pine Island for the scientists.
The plan is to construct the facilities at Byrd Camp this year and to transport all of the equipment for a second field camp at PIG, according to Chad Naughton, a Science Planning manager for Raytheon Polar Services Co. (RPSC), the prime logistics contractor to the NSF.
Tractors and sleds will haul all of the equipment needed to establish a camp near the ice shelf in 2010-11, traversing about 700 kilometers of snow and ice twice in one season. “Everything will be out there,” Naughton said. In addition, LC-130 ski-equipped planes flown by the New York Air National Guard will transport two helicopters to a third field camp at stormy WAIS Divide, site of a five-year, deep-ice coring project.
The helicopters will solve the problem of landing safely on the PIG ice shelf, an 800-square-mile slab of ice that floats on an eponymous bay that opens up into the Amundsen Sea. The helicopter camp will be about 2,000 kilometers from McMurdo Station, the logistics hub of the USAP.
“I know we’re at the cutting edge of science, but we’re also at the far edge of logistics,” Bindschadler said.
Down the hole
The scientists are still more than two years away from setting their boots back on the ice shelf, where they face a sort of Mission Impossible operation, even after many years of planning and thousands of kilometers of travel.
To see below the ice shelf and into the ocean, they must use a hotwater drill to bore a narrow, 5½-inch-diameter hole about 500 meters or more through the ice. First, they’ll send a camera down the hole to look at the ice cavity. After retrieving the camera, they’ll widen the hole to send an ocean profiling instrument down into this hidden realm.
The profiler will move vertically up and down on a cable through the entire water column to measure and monitor the complex ocean currents drawing warm, deep water onto the continental shelf, across the Amundsen Sea and then beneath the underside of the ice shelf.
“It’s a very, very deep, tiny little hole,” mused Tim Stanton, whose Ocean Turbulence Laboratory in the Oceanography Department at the Naval Postgraduate School first developed the profiler technology for the Arctic. “It’s a matter of hours to get this all done after the hole is made” because the hole will re-freeze.
Eventually, the scientists plan to deploy four ocean profilers over two field seasons beginning in 2011-12. Aside from six forays under the ice shelf by a robotic sub earlier this year by researchers collaborating with the PIG investigators, the information gleaned from the profilers will be among the first measurements of the ocean cavity.
“Anything we find will be a step forward,” Stanton said.
The first bite
The researchers won’t be idle for the next two years. This coming field season Holland will return to the instruments he set up in 2007-08 to perform maintenance, and to install three additional AWS systems for scientific and logistics purposes. A separate team will work at a spot called Windless Bight on the Ross Ice Shelf near McMurdo Station to test the drilling and ocean profiler systems.
“The tolerances on this are so tight, we feel it warrants testing — what I call the choreography of all this,” Bindschadler said. “We don’t have much time to pull the hotwater drill hose out and get the profiler down. We’ve got one shot at doing it. If it gets stuck, there are going to be a lot of unhappy people.”
Bindschadler noted that the profiler, while proven technology, has never been put together in the configuration required to squeeze down the long rabbit hole at PIG. While the ice shelf at Windless Bight is perhaps only 100 meters at its thickest point, the operation is important to bring the entire team together to not only rehearse each person’s role but to build cohesion among the members, according to Bindschadler.
“Part of the practice is to live together at a field camp and eat each other’s cooking,” he said of the two- to three-week expedition. “We will learn a lot in that process and come together as a scientific team, I have no doubt.”
Bindschadler said the team hopes to get some meaningful data out of the test as well. “The profiler will have some interesting ocean conditions to profile. It won’t just be a test of the choreography,” he added. “There actually will be some interesting data come from this that will tell oceanographers how the water circulates around Ross Island and the ice shelf.”
Meanwhile, Holland expects to spend about two weeks at Byrd and smaller field camps in the backcountry of West Antarctica setting up the AWS systems to help with flight operations and to monitor weather over the Amundsen Sea. That information is important for the models that he and others will eventually develop to help explain and predict the ocean, atmosphere and ice processes in that dynamic region.
Holland said he is hopeful to finish his job in about two weeks, but based on his previous field experience in West Antarctica, he takes a philosophical approach to the work.
“There are many complications that cause one to spend a great amount of time at these camps eating vast amounts of chocolate,” he said. “It’s a logistics challenge and it’s a science challenge, and success is guaranteed in neither.”
NSF-funded research in this story: Robert Bindschadler and Alberto Behar, Goddard Space Flight Center, Award No. 0732906; Tim Stanton, Naval Postgraduate School, Award No. 0732926; David Holland, New York University, Award No. 0732869; Sridhar Anandakrishnan, Penn State University, Award No. 0732844; Miles McPhee, McPhee Research Company, Award No. 0732804; and Martin Truffer, University of Alaska, Fairbanks, Award No. 0732730.
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