The alchemy of sample preparation
The method of gently releasing the air contained in the oldest ice will be at least as important as the actual measuring device; otherwise, the air could be contaminated in the extraction device or via chemical reactions from the ice itself. “The art – the alchemy – is in the extraction. That’s our strength; we’re the world’s specialists for that,” says Hubertus Fischer with an impish smile. The apparatus that Fischer and his team want to build to extract 1.5 million-year-old air will work roughly like this: The ice will be irradiated with infrared light and sublimated, then the water vapour will be frozen on a cold surface and finally, only the components of the atmospheric air will remain.
In Hubertus Fischer’s office there is a strange sculpture made out of signposts. It is modelled after the “Totem poles” to which expedition members at polar research stations attach signs showing how far they are from home. Fischer’s office version was created in 2008 for an informative meeting at the University of Bern. It shows the locations of all of its European ice core partners. One of the signs reads “Oldest Ice, Antarctica” – written in red and punctuated with a question mark. “You can see how long I’ve been thinking about this project,” says the researcher.
Indeed, this project requires a lot of perseverance. If all goes well, the first drilling season will take place in 2019/2020. And by the time the deepest part of the ice core is lifted and can be examined, it will probably be 2022. “The machine that we’re building as part of ‘ deepSLice’ won’t see the oldest ice over the course of the project,” says Hubertus Fischer, “but when the drilling begins, everything has to be finished and tested, and we want to be ready with the perfect analytics.”