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Home / Science / BBC – Future – The ancient memories of the glaciers of the world

BBC – Future – The ancient memories of the glaciers of the world



François Burgay talks about a cacophony of hums in a crowded Swiss laboratory and talks about the quiet, open skies above Mont Blanc. "At 4,200 meters above sea level, you would never expect the night to be so bright," he says. It is the lack of light pollution from the earth that gives the sky its unique milky quality.

"I think I can speak for many of my colleagues when I say that I have to be an explorer for this job," he smiled.

Burgay, a glaciologist at the Ca 'Foscari University of Venice in Italy, camped at the iconic summit that separated France and Italy in August 2016 for a week, the first field mission of his career. As part of the Ice Memory project, he collected ice cores from the Col du Dome glacier, which were then flown downhill and stored in the Grenoble laboratory. One day, researchers hope, some of these ice cores will go down to the Antarctic, where a vault of snow preserves its knowledge for centuries.

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After this first mission, the team broke the Illimani Mountain in Bolivia this time reaching a glacier on the side of a 6,300-meter summit and collecting cores that had to be carried on foot as helicopters were not available. The Kilimanjaro in Tanzania is the next on the list. An expedition is planned for the end of this year. Other endangered glaciers will follow as new international partners join the Franco-Italian initiative.

Studies show that the world's glaciers have been shrinking dramatically for some time now, probably due to man-made climate change. The United Nations Intergovernmental Panel on Climate Change estimates that if global warming continues unabated, we could lose most of the planet's ice cover by the end of the century, with the exception of Greenlandic and Antarctic ice sheets.

"The glaciers of the world are literally disappearing under our feet," says Carlo Barbante, paleoclimatologist, also at Ca & # 39; Foscari University and one of the founders of the Ice Memory project. For the 1

.5 billion people who put drinking water and irrigation on glaciers, this is a catastrophic situation. But the ice in the glacier area is also a wealth of information.

The world's glaciers literally disappear under our feet – Carlo Barbante

"We often focus on the immediate threats of ice melting, such as drought in vulnerable areas such as the sub-Indian continent," says Barbante. "As scientists studying ice like an archive, we find that we also lose important information, and we felt we had to do something about it."

French climatologists and glaciologists Barbante and his team set to work To rescue ice samples from the glaciers of the world. Each core of ice represents a valuable archive of history that spans thousands of years into the past. Included in the ice are tiny gas bubbles, dust particles, pollen, and even tiny organisms that can provide an important window for events that took place before human records began.

Currently the ice cores are extracted by one meter each. Drilling the surface of the glacier. A first visual analysis of the core is made before it is prepared for shipment in containers of a width of normally 10 cm. This process is repeated hundreds of times as explorers drill deeper and deeper to trap older layers of ice and sometimes reach extreme depths of 900 meters. As researchers dig deeper, each meter of ice is more compressed by the weight of the overlying layers, meaning that they store chemicals and other particles that have accumulated over a longer period of time.

Once in the lab, the cores are cleaned and samples taken are slowly melted in a controlled environment so that the glaciologists can analyze the water to identify metals or gases such as carbon dioxide.

Each core of ice is a valuable archive of history, dating back thousands of years

"Ice also works as a paleothermometer," says Burgay. "It captures the temperature of the environment where a given blanket of snow fell at any given time."

With this information, researchers can reconstruct Earth's climate evolution over millennia and provide valuable information that scientists can use to model climate change. For example, the machines in Burgay's lab are currently looking for traces of iron in 6,000-year-old ice from a kernel that was recovered in Greenland. The tiny amounts of metal can provide clues to ancient volcanic activity that has thrown metallic dust into the atmosphere.

After cleaning, the remaining cores are prepared for long-term storage in the repository.

"One can argue that ice cores would do this, be sure in a standard refrigerator in Venice or Paris," says Barbante. "But we do not think at short notice, we can not predict if 200 years later someone will be able to pay the electricity bill." History shows how conflicts, the shifting of research priorities and natural disasters make it difficult to predict the future of long-term scientific endeavors, he says.

It has led the scientists to seek a more permanent solution.

"Antarctica is the safest place to store the samples," says Barbante. "First, because it's a natural refrigerator with annual average temperatures of -50 ° C, and because it does not belong to a particular country is the only region destined for peaceful scientific endeavor. "

The creation of a protected area for today's vanishing ice could still offer unimaginable benefits today.

The Antarctic Treaty, signed in 1959 and coming into force in 1961, brings 53 states active in the region together to use the territory "for peaceful purposes only" and "to exchange and make freely available scientific observations and results from Antarctica".

According to Bess Koffmann, a geologist at the University of Maine in the US, the Antarctic will remain a safe place. However, the contract is available for renegotiation in 30 years. (Read more about how archaeological discoveries can shape the future of the continent.)

"There is always the danger that a country will refuse to sign the agreement in order to use the region's untapped resources , z as coal and other minerals, "warns Koffmann.

The creation of a protected area for today's disappearing ice could also bring benefits that are unimaginable today. As new tools and technologies become available, it may allow scientists to open new windows into the past of our planet and perhaps even study old viruses and ice-conserved bacteria.

"Technologies have developed rapidly in recent decades, and we are now taking measurements that we did not even dream of 30 or 40 years ago," says Koffmann.

We lose our glaciers very quickly, and without archiving the information they contain, we just do not stand a chance. Understand possible changes in the future – Emma Smith

One day, according to Barbante, imaging techniques are so advanced be that "we can analyze the cores without touching them".

But to get to By this time, it is imperative to build a repository while we still can, says Emma Smith, a glaciologist and geophysicist at the Alfred Wegener Institute in Bremerhaven: "We lose our glaciers very fast and without We do not give ourselves a chance to understand changes that may occur in the future. "

Scientists often focus on Polar ice, because that's where the oldest data can be found, says Smith. "But if you look at regional ice cores from smaller glaciers, you can observe changes on a much smaller scale." This means that a detailed picture of the local climate is created, which alone would be missing in an analysis of the polar ice.

The Ice Memory team hopes that a large selection of samples will be available for storage in the Antarctic until 2020 in a purpose-built vault near the plateau French-Italian research station Concordia. The researchers plan to use a successfully tested method in Greenland, where a trench is dug and an inflatable balloon is used as the mold for the cave.

"Then we blow the previously removed snow to create it, dig the ditch back onto the structure and wait for it to harden for a few days," explains Barbante. At this point, the balloon is deflated and can be easily removed. "In this way, we create a natural structure that is cost effective and has no impact on the environment."

Barbante admits that after one or two decades, the structure is likely to fall under the weight of further snow falling on it. "However, the cores are relatively easy to move to a new structure built the same way," he adds.

The project has already found the support of Unesco, and Barbante says that more and more teams, including from Russia, The US and China are already collecting additional material during their independent expeditions, so they will contribute to the project in the future can afford.

According to current forecasts, no matter what we do now to reduce global emissions, many of the world's glaciers have little hope of surviving beyond a few human generations. Some lose a third of their ice in the third century. These few hundred meters of ice cores would soon only consist of many old ice tongues.

The efforts of some intrepid explorers venturing into the mountains to collect these seeds help unlock the secrets available for unlocking future generations.

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