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People drill into frozen ground
Photo Credit: James Bockheim
University of Wisconsin-Madison graduate students Adam Beilke, left, and Kelly Wilhelm drill a shallow borehole at a site known as Old Palmer on an island off the west coast of the Antarctic Peninsula. The researchers are monitoring changes in permafrost.

Hitting the ground

International project monitors permafrost in Antarctica

The thawing of frozen soil in the Arctic is becoming a familiar story. Concerns range from the release of powerful greenhouse gases into the atmosphere to the destruction of infrastructure like roads and buildings as the ground collapses from the melting of ice-rich permafrost below.

The picture in the Antarctic is less clear, largely due to the scarcity of monitoring sites until recently. An international effort is now under way to learn more about the characteristics of Antarctic permafrost and its sensitivity to climate change.

The program is called PERMANTAR External Non-U.S. government site, for Permafrost and Climate Change in the Maritime Antarctic. James Bockheim External Non-U.S. government site, a professor in the Department of Soil Science at the University of Wisconsin-Madison External Non-U.S. government site, is leading the nascent U.S. efforts off the western side of the Antarctic Peninsula where the U.S. Antarctic Program External U.S. government site maintains a research station.

“We chose Palmer [Station] External U.S. government site because it is in the heart of that western part of the Antarctic Peninsula where the greatest warming has been observed anywhere else on the Earth in terms of the climate,” Bockheim said.

Climate records from a Ukrainian research base, Vernadsky Station External Non-U.S. government site, less than 50 kilometers from Palmer go back more than five decades. Bockheim said the data show that the mean year-round air temperature has increased by 3 degrees Celsius — and more than triple that during just the winter. 

People gather around instrument in cold place.
Photo Courtesy: James Bockheim
Scientist James Bockheim discusses his team's soil climate station to support staff from Palmer Station.
Person takes samples from ground.
Photo Credit: Goncalo Vieira
James Bockheim describes a soil sample on Deception Island during fieldwork for the PERMANTAR program.

Bockheim has a four-year project from the National Science Foundation’s Office of Polar Programs External U.S. government site to monitor the soils and permafrost, or permanently frozen ground, on islands in the region. He is particularly interested in characterizing the carbon content in the Antarctic soils — a task he has undertaken in the Arctic.

“In the Arctic, there’s a lot of carbon locked up in the upper part of the permafrost,” he explained. “The concern in the Arctic is that as you warm those soils and increase the thickness of the active-layer — in other words, the depth to the permafrost table — the carbon can be available for oxidation chemically and by microorganisms and go back into the atmosphere as CO2, and that exacerbates the warming.”

Carbon dioxide is a key greenhouse gas that helps trap heat in the lower atmosphere, warming the planet. It is rapidly approaching 400 parts per million — higher than any time in the last 800,000 years, based on ice core records.

However, Bockheim said researchers believe climate change in the Antarctic may be a double-edge sword when it comes to the carbon cycle.

“In the Antarctic, with the warming of the climate there, we’re going to see, and we are already seeing in certain places, an increase in the vegetation, an increase in biomass, and an increase in soil organic matter. So, the Antarctic might become a receptacle for the carbon, which is in contrast to the Arctic,” he said.

But it is unclear how effective new vegetation may be in sequestering carbon dioxide. A paper published two years ago in the journal Nature suggested that additional tundra plant growth from climate change in the Arctic may initially keep up with rising carbon dioxide. But if thawing continues, the permafrost will spew carbon for decades, and the plants will become overwhelmed.

Less than .5 percent of Antarctica isn’t covered by ice. However, Bockheim and his colleagues predict that while the soils of the Antarctic Peninsula and offshore islands comprise only 20 percent of the ice-free area of Antarctica, they will account for more than 80 percent of the soil organic carbon.

Hence the need to monitor the soils around the peninsula region.

Image of YouTube video
 
Click on the image above to see a YouTube video interview with James Bockheim on his research involving permafrost. The link will take you away from this page to a nongovernment website.

Bockheim, who has previously worked on the far colder, drier soils of the McMurdo Dry Valleys External U.S. government site in the Ross Sea region, made his first trip to the Antarctic Peninsula area in January, visiting Deception and Livingston islands in the South Shetland group.

He and two students then worked out of Palmer Station for nearly a month over March and April to install shallow soil monitoring stations that consist of strings of sensors that measure soil temperature at regular intervals. The data from the thermistors will give the researchers an idea about the thickness of the active-layer depth — the portion of the ground that regularly thaws and freezes during the year.

This year the small team from Madison will be joined by two colleagues from Portugal to install deeper boreholes that will monitor temperatures in the permafrost as far down as 15 meters at sites around Palmer Station and at an Argentine station about 100 kilometers north.

All the data from PERMANTAR will feed into a computer model that can predict the possible carbon flux and other impacts from climate change based on the temperature, chemistry, depth and distribution of permafrost.

Surprisingly, the soils of the Antarctic Peninsula offshore islands are somewhat similar to those in the Arctic, according to Bockheim. In fact, the Palmer area receives almost as much rainfall as Madison, he noted.

“To me, it’s like working in Alaska in August or September when it’s spitting rain and snow,” he said.

NSF-funded research in this story: James Bockheim, University of Wisconsin-Madison, Award No. 0943799 External U.S. government site.  

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Curator: Peter Rejcek, Antarctic Support Contract | NSF Official: Winifred Reuning, Division of Polar Programs