Moving rapidly and punctiliously in two layers of gloves, Florian Krauss units a dice of ice into a gold-plated cylinder that glows purple in the mild of the aiming laser. He steps again to admire the machine, coated with wires and gauges, that turns polar ice into local weather information.
If this had been an actual slice of treasured million-year-old ice from Antarctica and never only a check dice, he’d subsequent seal the extraction vessel underneath a vacuum and energy on the 150-megawatt primary laser, slowly inflicting the complete ice pattern to sublimate straight into fuel. For Krauss, a PhD scholar at the University of Bern in Switzerland, this is able to unlock its secrets and techniques, exposing the concentrations of greenhouse gases like carbon dioxide trapped inside.
To higher perceive the function atmospheric carbon dioxide performs in Earth’s local weather cycles, scientists have lengthy turned to ice cores drilled in Antarctica, the place snow layers accumulate and compact over a whole lot of 1000’s of years, trapping samples of historic air in a lattice of bubbles that function tiny time capsules. By analyzing these bubbles and the ice’s different contents, like mud and water isotopes, scientists can join greenhouse-gas concentrations with temperatures going again 800,000 years.
Europe’s Beyond EPICA (European Project for Ice Coring in Antarctica) initiative, now in its third 12 months, hopes to ultimately retrieve the oldest core but, relationship again 1.5 million years. This would prolong the local weather report all the method again to the Mid-Pleistocene Transition, a mysterious interval that marked a serious change in the frequency of Earth’s climatic oscillations—cycles of repeating glacial and heat durations.
Successfully drilling a core that outdated—a years-long endeavor—could be the simple half. Next, scientists should painstakingly free the trapped air from that ice. Krauss and his colleagues are creating an progressive new technique to do that.
“We’re not interested in the ice itself—we’re just interested in the air samples included, so we needed to find a new way to extract the air from the ice,” he says.
Melting isn’t an possibility as a result of carbon dioxide simply dissolves into water. Traditionally, scientists have used mechanical extraction strategies, grinding up samples of particular person layers of ice to free the air. But grinding wouldn’t be efficient for the Beyond EPICA ice in the college’s storage freezer, which is stored at 50 °C beneath zero. The oldest ice at the very backside of the core will be so compressed, and the particular person annual layers so skinny, that bubbles received’t be seen—they’ll have been pressed into the lattice of ice crystals, forming a brand new part known as clathrate.
“At the very bottom, we expect 20,000 years of climate history compressed in only one meter of ice,” says Hubertus Fischer, head of the past local weather and ice core science group at Bern. That’s a hundredth the thickness of any present ice core report.
The new methodology Krauss and Fischer are creating known as deepSLice. (A pizza menu is taped to the facet of the system proper underneath the laser warning labels, a present from a pizzeria in Australia with the similar identify.) DeepSLice has two elements. The Laser-Induced Sublimation Extraction Device, or LISE, fills half a room in the staff’s lab area. LISE goals a near-infrared laser constantly at a 10-centimeter slice of ice core so that it turns straight from strong to fuel underneath extraordinarily low stress and temperature. The sublimated fuel then freezes into six steel dip tubes cooled to fifteen Ok (-258 °C), every containing the air from one centimeter of ice core. Finally the samples are loaded into a custom-made absorption spectrometer based mostly on quantum cascade laser expertise, which shoots photons via the fuel pattern to measure concentrations of carbon dioxide, methane, and nitrous oxide concurrently. Another huge benefit of this technique is that it takes rather a lot much less ice (and work) than the outdated methodology of study, by which scientists measured methane by melting ice (it doesn’t dissolve into water) and measured carbon dioxide by grinding ice.
DeepSLice affords “a unique capability that nobody else has,” says Christo Buizert, an ice core scientist at the University of Oregon and the ice evaluation lead for COLDEX (the Center for Oldest Ice Exploration)—the US equal of Beyond EPICA, which is at the moment in a “friendly race” with the Europeans to drill a steady core right down to 1.5-million-year-old ice.
“What they’re trying to do, sublimating ice—people have been trying this for a long time, but it’s one of the most challenging
ways to extract gases from ice,” Buizert says. “It’s a very promising way, because you get 100% of the gases out, but it’s very difficult to do. So the fact that they’ve managed to get it working is very impressive.”
Krauss and Fischer nonetheless have about three years earlier than they get their arms on that part of vital ice. There are nonetheless kinks to iron out, like learn how to recapture the samples from the spectrometer for extra evaluation, however they suppose they’ll be prepared when it lastly arrives in freezer containers on a ship from Antarctica by way of Italy.
“Our latest results showed us we are on a good track, and actually, we achieved the precision we wanted to,” Krauss says. “So I’m sure it’s going to be ready.”
Christian Elliott is a science and environmental reporter based mostly in Chicago.
…. to be continued
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