Scientists are digging up the world鈥檚 oldest ice in Antarctica, which is believed to be 1.5 million years old, to help them predict future climate change.
The British Antarctic Survey鈥檚 Robert Mulvaney, who is the U.K lead for the project, told 麻豆传媒 Channel that drilling and retrieving the old ice core is crucial in understanding the Earth鈥檚 prehistoric atmosphere.
鈥淲e鈥檙e looking into the past but it actually should inform what we鈥檙e expecting our climate will looking like in 100 years,鈥� he said from Vienna. 鈥淲e鈥檙e trying to do a very, very long-range weather forecast.鈥�
Researchers from 14 European scientific institutions will analyze the ice to get a snapshot of the world and its atmosphere over 1.5 million years ago -- including the levels of carbon dioxide, methane and other greenhouse gases.
Mulvaney's team from the consortium led by the Germany-based Alfred Wegener Institute are interested in trapped air in the ice. He explained that fresh snow in polar regions like Antarctica has air percolating around it. But that air becomes trapped by new layers of falling snow.
鈥淎s it gets deeper into the ice, that air is all squished into discrete bubbles and those bubbles remain in the ice forever,鈥� he said. 鈥淲e can take those bubbles out of the ice and measure what was in the atmosphere hundreds of thousands of years in the past.鈥�
鈥淚t鈥檚 the only record on Earth of the past atmosphere,鈥� Mulvaney said.
With the new project, the team will drill into a continuous ice core in an area identified as Little Dome C to take out a couple thousands-metre-long cylinders of ice. It will help them understand the shift in the frequency of prehistoric ice ages.
2nd project of its kind
The new six-year project 鈥淏eyond EPICA鈥� -- an acronym of European Project for Ice Coring in Antarctica -- actually follows a 10-year project called 鈥淓PICA鈥� which concluded in 2004.
In that case, scientists from 10 European nations drilled into the base of Antarctica and took out a 3,000-long ice core.
鈥淲ith that [ice] core we were able to reconstruct the climate and the atmosphere looked like over the past 800,000 years,鈥� he explained, adding they saw a 鈥渟trong link between the greenhouse gases in the atmosphere and the climate.鈥�
Mulvaney explained it was very clear from ice cores they鈥檝e extracted -- which gave them a comprehensive climate record -- that there鈥檚 an ice age every 100,000 years.
But an examination of marine sediment records shows that beyond a million years ago, there was an ice age every 40,000 years. 鈥淎nd we don鈥檛 really know -- as a climate scientists -- why,鈥� Mulvaney said.
鈥淪o we鈥檙e fairly sure that the answer lies in the atmosphere [of] the time,鈥� he said. 鈥淲e鈥檙e effectively running a forecasting model.鈥�
