“A needle in a haystack.” That’s what scientists are trying to find out. Oldest ice exploration center (COLDEX), in their own words. In the huge ice core of East Antarctica, they are really busy looking for the oldest possible chunks of ice. The goal? Learn more about Earth’s past climate in order to anticipate its evolution in the near future. In this area, where they set up their first research base, the researchers suspect that the ice may contain information from millions of years ago.
They therefore sent, as evidenced by a video shared on Twitter on December 23, 2022, their camera 93 meters deep into a circular hole dug in the Antarctic soil twenty years ago. The oldest specimen identified so far testifies to changes in climate and atmospheric carbon dioxide levels over the last 2.7 million years. A real age that still needs to be confirmed by further tests.
Even older ice cream, but well hidden
Scientists plan to dig deeper. “It would even be remarkable if we could go back three or four million years or even more”explains Edward Brook, climate researcher at Oregon State University (USA) and director of the COLDEX project interviewed by the antarctic sun. However, this is no small feat: although much of Antarctica has been covered in ice for millions of years, it is not fixed and is constantly being thrown into the ocean. To identify the few places where it could be preserved, large areas of the eastern ice sheet, considered the most stable area, are studied. The soil at the drill sites must be sufficiently thick, cool and undisturbed by the rock below to preserve the precious pieces. “We are looking for the perfect place where there will be a complete sequence of ice about two miles (about 2.3 kilometers, editor’s note) thick”specifies to our colleagues Peter Neff, a glaciologist at the University of Minnesota and a member of the team.
⋙ Immersed under the ice cap, this geologist explored the bowels of Greenland
In the polar ice caps, air bubbles testify to a climate of the past
It is by analyzing the air bubbles trapped in the ice that experts gain insight into the climate of the past: during the formation of a glacier, the air bubbles compress and become trapped there. Their analysis therefore indicates what the atmosphere was like when they were formed, in particular the amount of carbon dioxide present in the air. And at the same time, it could allow identifying the sensitivity of the polar ice caps to higher levels of greenhouse gases and anticipating how they might react to higher temperatures. During the first phase of the COLDEX project, which will last five years, the researchers will investigate (airborne radar surveys, ground-level explorations) to find the famous sites that probably hide ice that is more than two million years old. All this during the southern summer, where temperatures remain below -20°C and frequent snowfalls.
Despite these difficult weather conditions, it is possible to follow (almost) live the various developments of the Science and Technology Centers (National Science Foundation). Using SpaceX’s Starlink service – which covers “the most remote regions of the world”Pitcairn Island, Easter Island and now Antarctica — Peter Neff can share the research team’s results and surprising daily life on TikTok (@icy_pete) and Twitter (@icy_pete), thanks to this satellite connection.
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