Scientific campaign brings new insights to East Antarctica, broadens international collaboration
Posted April 3, 2009
The International Polar Year (IPY) officially comes to a close this month. But the legacy of the two-year campaign to learn more about the world’s polar regions will likely last far into the future.
IPY scientists accomplished a dizzying amount of work in the Antarctic and Arctic — from mapping rugged mountain ranges buried hundreds of meters below the ice cap to making underwater observations below an ice shelf. They crisscrossed Antarctica on ski-equipped airplanes and on tracked vehicles. Ice-strengthened ships carried them to little-visited corners of the Southern Ocean, discovering new species in the frigid waters.
The effort involved more than 60 countries and 10,000 scientists, including many funded by the National Science Foundation (NSF), which manages the U.S. Antarctic Program (USAP).
“The glimpses I’ve had of the data sets from this season and last year are astounding. I’m very pleased with our investments in IPY,” said Antarctic Sciences Division Director Scott Borg in the NSF’s Office of Polar Programs.
Launched in March 2007, the IPY actually spanned a two-year period to encompass seasonal research in both polar regions. Several of the larger Antarctic projects will continue for several more years.
One such project is ICECAP, for Investigating the Cryospheric Evolution of the Central Antarctic Plate, which just completed the first of three field seasons.
ICECAP researchers used a converted World War II-era DC-3 aircraft, outfitted with a suite of geophysical instruments, to fly over a region of East Antarctica to measure the thickness of the ice sheet and the texture, composition, density and topography of the bedrock below the ice.
The scientists — representing the United States, the U.K. and Australia — believe two subglacial basins that sit well below sea level, but hidden by the ice, could help speed the flow of ice into the ocean, raising sea level. Funding for the project came from NSF, the U.K. Natural Environment Research Council, the Australian Antarctic Division and the University of Texas. The researchers will use both U.S. and Australian facilities for the experiment.
“This is a real IPY project, where everybody is chipping a lot in,” noted Don Blankenship, a research scientist at the Jackson School’s Institute for Geophysics at the University of Texas at Austin and ICECAP principal investigator.
Another IPY project, Antarctica’s Gamburtsev Province (AGAP), also used aircraft to survey East Antarctica and the bedrock below its icecap, but focused on a ragged mountain range buried in the ice that was first discovered more than 50 years ago during the International Geophysical Year (IGY), a predecessor to the IPY. The project also used seismometers to image the area.
The sharp peaks showing in the raw data suggest the East Antarctic Ice Sheet formed quickly, because the slow grind of glacial movement didn’t wear down the mountains into a plateau.
“People will be digesting those data and interpreting them for quite a while,” Borg said. “We can look forward, in the next year or two, to a lot of papers describing the data, and more importantly, inferring things about the subglacial continent and the ice sheet.
“The AGAP and ICECAP projects are going to give us some very fundamental information about the continental surface beneath the ice cap. … Those are data sets that will be mined for decades into the future,” he added.
The aerial surveys by both projects should also help scientists locate the continent’s oldest ice, estimated to be more than 1 million years old. The oldest ice core recovered to date is about 800,000 years old, coming from the European Program for Ice Coring in Antarctica (EPICA) project conducted earlier this decade.
One-million-year-old ice isn’t just a big number. It represents a time when the duration of glacial cycles more than doubled. Some time before 1 million years, ice ages waxed and waned on a 41,000-year cycle. Now, it’s a 100,000-year cycle. Understanding what flipped the switch is important for climate change researchers trying to model the pull-and-tug between temperature and greenhouse gases.
“That’s why people are interested in getting a hold of this old ice,” Borg said. “The radar data sets will define areas where there is likelihood [of old ice].”
The World Meteorological Organization (WMO) and the International Council for Science (ICSU) hosted the first effort to synthesize the findings from the IPY effort, estimated at more than $1.2 billion from all participating nations. In a “State of Polar Research,” a report released in Geneva at the end of February by a joint IPY committee of the WMO and ICSU, scientists reported the effects of global warming on both poles.
The 16-page report said: “New assessments of the state of the Greenland and Antarctic ice sheets have been made using novel techniques. These include satellite measurements of changes to the elevation and the gravitational fields of the ice sheets. … These assessments continue to be refined, but it now appears certain that both the Greenland and the Antarctic ice sheets are losing mass and thus raising sea level, and that the rate of ice loss from Greenland is growing.”
The ocean appears to play an active role in ice melt. A project led by Stan Jacobs, with Lamont-Doherty Earth Observatory at Columbia University, aboard the USAP’s RVIB Nathaniel B. Palmer, is monitoring the incursion of slightly warmer water onto the continental shelf in an area of West Antarctica called Pine Island Bay — home to one of the continent’s fastest moving glaciers.
The ocean-ice shelf interaction is another important variable as the science community attempts to calculate sea-level rise, with recent reports estimating a one meter increase by century’s end.
“My expectation is that this cruise collected a lot of data to advance understanding of that process, but I haven’t seen the data sets yet,” Borg said.
One expectation is that the spirit of IPY — the broad international cooperation it fostered — will live well past this month. In light of the current global recession and the increasing cost and scope of polar research, it seems collaboration between nations must continue.
That’s the conclusion Tom Neumann, expedition leader of the second leg of a joint Norwegian-U.S. IPY Traverse across East Antarctica, made after the team completed the nearly 5,000-kilometer-long overland journey to study climate variability.
“This project has been carried out in the true spirit of the International Polar Year,” Neumann wrote on the expedition’s Web site dated Feb. 23. “Neither the U.S. nor Norway could have completed this project, either scientifically or logistically, on their own. Our collaboration has been the key feature of this project.”
Ted Scambos, lead scientist at the Boulder, Colo.-based National Snow and Ice Data Center and member of the Norwegian-U.S. IPY Traverse, said the new level of cooperation led to unprecedented scientific advances in East Antarctica.
“I think one of the main legacies of IPY is that it really opened up East Antarctica. We knew some things about East Antarctica from [the IGY], the earlier traverses through the 1960s, but we didn’t know a whole lot.”
The Norwegian-U.S. IPY Traverse, for instance, will add new details to the climate record of East Antarctica from the last millennium. The traverse scientists also mapped out a region of subglacial lakes called the Recovery Lakes. And AGAP, ICECAP and other projects all contributed to a more robust understanding of East Antarctica, which contains enough ice to raise sea level by 60 meters should it all melt. (An unlikely scenario for thousands of years.)
“All of that puts East Antarctica into the same league as West Antarctica in terms of understanding what kind of player it is in the ocean-ice system,” Scambos said.
Borg said he anticipated more logistically challenging projects in the future, but said the NSF had not funded anything specific at this time. “We do have active interest in collaborating in new ice-coring sites in the near future,” he said. “And I’m sure things like AGAP will come along in future.”
The report from the WMO and ICSU stressed the need for further research into the Antarctic and Arctic, based on the findings from IPY.
“The polar regions are an integral and rapidly changing part of the Earth system. Humankind’s future environment, well-being and sustainable development require that we comprehensively understand and observe polar systems and processes and the changes that are already upon us,” the report concluded. “The message of IPY is loud and clear: what happens in the polar regions affects the rest of the world and concerns us all.”
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