Sending ice to Antarctica

Scientists are planning to ship ice to the Antarctic. They're afraid that mountain glaciers around the world are melting as a result of climate change and want to store samples of ice in a new vault in the coldest place on Earth.

At 4,350m the Col du Dome sits just below the summit of Mont Blanc.

Covered in snow, it appears to be a permanent, frozen fixture in the Alps - but looks can be deceptive.

"In 1994 we measured the temperature inside the glacier and in 2005 we went to the same place and we saw a warming of 1.5C," says Jerome Chappellaz, of the French National Centre for Scientific Research which is involved in creating a new ice store in the Antarctic.

"When it comes to non-polar glaciers, because of global warming, a lot of them are going to disappear this century and those at the highest altitudes are already experiencing summer melting.

"We are probably the only scientific community whose archive is in danger of disappearing from the face of the planet. If you work on corals, on marine sediments, on tree rings, the raw material is still here and will be for many centuries," he says.

Only a tiny amount of mountain glacial ice has ever been collected and studied, and in 2016 the Col du Dome will become the first contributor to an Antarctic ice vault.

The archive will be housed in a snow cave at the Concordia Research Station - a permanently manned base, jointly operated by scientists from France and Italy.

Stored safely in a giant frozen trench, the ice cores can simply be sealed in bags 10m below the surface where the temperature maintains a steady temperature of -50C.

"We know even with global warming, even if Antarctica warms up by a few degrees we still have access to the best freezer on the planet. We know the ice will be safe there for decades or centuries," says Chappellaz.

The team will use special drills to extract cylindrical ice cores from the Col du Dome. At more than 130 meters long and around 10cm in diameter the samples need to be brought to the surface in sections.

In the Alps the team can reach the site by helicopter - their delicate cargo can be packed in specially designed freezer crates and flown down the mountain.

But a second mission in 2017 will be much harder. They will be going to the Illimani mountain in the Bolivian Andes - at 6,300m the summit is too high for a helicopter so the heavy drills and other equipment will need to be carried by hand.

"The ice cores have to be bought down to base camp by men so that's a tough job. And it has to be done at night because usually in the day it is too warm and that could be dangerous for the ice cores," says Chappellaz.

The teams will collect three ice cores from the Alps and three from the Andes. Two from each location will be taken to Antarctica while the others will be sent to a laboratory in France for analysis.

Glacial ice, which is formed on land, is made of snow that has built up in layers over thousands of years.

"The smart bit is in between the snow crystals you get trapped air bubbles... those air bubbles contain actual atmospheric samples of when that ice was formed," says polar oceanographer Mark Brandon from the Open University.

Drilling down into this glacial ice and extracting an ice core means scientists are taking a journey back in time. Analysing the bubbles tells them what the climate was like at different periods of the Earth's history.

"We know carbon dioxide in the atmosphere is higher now than in the last three million years," explains Brandon. "Ice contains an absolutely unique record of our climate."

Gathering data from ice cores around the world will enable scientists to build computer models showing how the climate changed in the past and give us a much better insight into how it might change in the future.

"Most of the environmental information we gather from ice cores relies on those taken from Greenland and Antarctica and this is not enough, especially when it comes to pollutants and atmospheric compounds which only reside in the atmosphere for a short time," says Chappellaz.

"By getting access to their concentration at different sites, from the Andes, Alps, Rocky Mountains, the Himalayas it will help us understand the sources of pollutants which compliments the data from polar ice cores."

Polar ice can date back hundreds of thousands of years, while the earliest mountain ice that has been found is 18,000 years old - but because mountain glaciers are closer to populated areas they are a valuable source of information when it comes to tracking pollutants since the Industrial Revolution.

Comparing mountain ice with polar ice could enable scientists to determine what is human-induced change and what is natural climate change, but only if the data they collect can be trusted.

"In some of the warmer areas of the world the surface water is starting to melt. It then trickles all the way through the ice, taking with it the information from the surface so it's smearing out any record that we might be able to take from the past," says Robert Mulvaney, a glaciologist with the British Antarctic Survey.

He says ice cores need to be kept as cold as possible and Antarctica is the most reliable freezer on the planet. Another alternative would be to take them to a commercial cold storage unit, such as the one in Peterborough in the East of the UK, where the British Antarctic Survey keeps its samples.

At the last count it had 571 boxes the size of tea chests packed with Antarctic ice. "It's just a standard commercial freezer store. So it's got frozen peas going in and out and occasionally some ice cores will go in and out of it too," says Mulvaney.

One of the main concerns about storing the ice in this way is that the freezers could break down, or there could be a power cut, resulting in a giant puddle instead of a frozen legacy.

"Antarctica would allow you to maintain a much colder temperature than you could achieve in a commercial freezer," says Mulvaney.

The storage unit in Peterborough keeps the ice at -20C and research facilities can go down to -30C, but there are concerns that neither is cold enough. "If you don't store it at the same temperature you collected it then it looks like the integrity of the ice deteriorates over time. As the years go by we're measuring more and more exotic things in the ice and some of those things are proving not to be stable over time," he says.

"The safest storage we can come up with is central Antarctica and I like it. I prefer the idea of keeping it for posterity in Antarctica than paying money to keep it, in not such good conditions, in a grocery store."

The biggest problem is money though. Usually research agencies fund projects because they are looking for short term scientific feedback. Investing in expensive ice coring missions that may not yield results for decades is not such an attractive proposition.

The funds for the French mission have come from private sponsors and government research bodies. Chappellaz is hoping wealthy foundations and individuals who are concerned about global warming will fund further projects.

"We are really in the spirit of international endeavour. We want to have Chinese, American, Brazilians, Italians, Russians, and Swiss scientists involved. Any nation that has access to these kinds of glaciers can handle their own project and transport the ice cores to Antarctica. Concordia will become a long term hub for this ice core vault," he says.

In 2016, a team of Italian and Swiss scientists are due to embark on drilling projects on other sites in the Alps, and Chappellaz says they are thinking about joining their cores with his cause.

"This is a project not for us but a project for the next generation. Just like when you speak about climate change in general, we are one of the generations responsible - we won't suffer too much from the consequences but our children and grandchildren will. We have a special responsibility to future generations of scientists to provide them with an archive before it's too late."

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