This icy cylinder was bored from the Müller Ice Cap on Axel Heiberg Island (Umingmat Nunaat), Nunavut. “It is insanely deep for a small ice cap, meaning it likely offers us a really long climate record,” says Criscitiello. “There’s a big hole in our understanding of Arctic Ocean variability over long time periods … so this little island right at 80 degrees north in the Arctic Ocean became a target among a whole group of us.”

Joining Criscitiello on the ice was project lead Dorthe Dahl-Jensen (University of Manitoba) along with a team of ice and climate researchers from across Canada and Denmark, the Danes bringing both expertise and a very big, and advanced, drill. But before they broke the ice, the scientists did airborne and ground-penetrating radar surveys to image the ice from the surface down to the bedrock. By figuring out the deepest spots, where the layering in the ice looked “really nice,” and — importantly — where they could obtain an undisturbed climate record, the team could pick the ideal spot to drill.

Each time the drill goes down the borehole, it drills down only a couple metres before you’re “pulling it back up, swinging it, taking the ice out, sending it down again,” says Criscitiello. “When you get really deep, the travel time… you can wait an hour for it to get all the way down.” It took two months for the two teams (10 members in April; 13 in May) to secure the icy samples they needed for the lab. Then, “we had to get 613 metres of ice from the Arctic to where I’m sitting,” says Criscitiello, which “involved building temporary freezers on other Arctic Islands, on Ellesmere, in Yellowknife.”

Now that the ice is safely in the ice core lab, the real work begins: deciphering the past. Today, Criscitiello already knows the ice dates back more than 10,000 years to the last glacial maximum. “I’m most excited for this core’s likely ability to allow us to reconstruct Arctic Ocean sea ice in the past in a way we’ve never been able to actually observe or prove.”