Researchers seeking greater insights into how Earth's climate will evolve under a warming atmosphere are turning to one of nature's greatest time capsules for answers.
At a press conference this morning, a consortium of leading ice and climate scientists from 10 European countries announced project Beyond EPICA. The expedition, targeting one of the harshest environments on the planet, will focus on drilling and retrieving for analysis an ice core containing more than 1.5 million years of climate history.
Dr. Robert Mulvaney, an ice core scientist from British Antarctic Survey (BAS), said in a statement that the expedition is an attempt to build substantially on ice core data collected in 2004 chronicling 800,000 years of climate history.
"We learnt a huge amount about the critical periods between the shift from warm periods and ice ages," Mulvaney said of that earlier expedition. "Now we want to go back even further to beyond a million years ago, when the planet’s climate cycle between cold glacial conditions and warmer interludes changed from being dominated by a 41,000-year pattern to a 100,000 year cycle."
To the 'Dome'
Dome C is located on the Antarctic Polar Plateau, the world's largest frozen desert. (Photo: Stephen Hudson/Wikimedia)
For the past several years, the research team has been using ground-penetrating radar to scour several summits of the Antarctic Ice Sheet. They finally settled on "Dome C," one of the coldest places on Earth (with an average annual air temperature of minus 66.1 degrees Fahrenheit (minus 54 Celsius) and located on the frozen desert of the Antarctic Polar Plateau.
"To find the best drill site, we look for a number of different things in the ice," Mulvaney said. "Thickness is the first indicator. Different rates and volumes of snow accumulation, ice flow behaviour and the temperature at bedrock level help us determine whether old ice does indeed remain near the base of the ice sheet."
Ice cores are extremely valuable to researchers because of the way their layers trap small bubbles of ancient atmosphere that researchers can sample. Just like sticky amber can preserve trapped insects for millions of years, ice cores can capture airborne relics such as sea salt, volcanic ash, pollen, and other hints of Earth's past.
"This Little Dome C site is most likely to be the best location to find the right kind of ice that will tell us what we need to know," Mulvaney added.
Leveraging the nearby French-Italian research station Dome Concordia for support, the team plans to spend the next several years drilling nearly two miles from the surface to the ancient bedrock below. The massive ice core that's extracted will then be analyzed for clues as to how glacial cycles responded to inputs like carbon dioxide increases or changes in the Earth's rotational tilt.
"What we don’t yet fully understand is how the future climate will respond to increasing greenhouse gases in our atmosphere beyond 2100 and whether there will be tipping points in the system we are not aware of yet," said professor Olaf Eisen, project coordinator and glaciologist at the Alfred Wegener Institute (AWI). "It will be hugely helpful if we can understand what happens when the duration of natural climate cycles shifts. We can only get this information from the Antarctic ice sheet."