Dartmouth graduate student Jacob Chalif is far from home this holiday season. He’s in Antarctica on a mission to find the world’s oldest ice.

“It’s certainly a unique experience,” he said. “Everything you do, you have to adapt to do it in the freezing cold weather — getting out of your sleeping bag and getting dressed in the morning, brushing your teeth, going to the bathroom.”

Chalif is traveling as part of a COLDEX expedition — an effort led by the National Science Foundation Center for Oldest Ice Exploration to find the oldest possible ice core records.

About 20 years ago, Chalif says, European scientists drilled down in the middle of Antarctica and found ice that was 800,000 years old. A new challenge has teams of scientists from across the world trying to beat that record — their goal was to find ice 1.5 million years old.

But Chalif is with a team of Americans who have found a place where special conditions are lifting up even older ice — up to 6 million years old — to more accessible places on the surface. It’s called the Allan Hills.

“It’s a really good way of getting a high volume of really old ice for cheap, basically,” he said.

He said parts of the trip have been difficult, with cold and windy conditions. But it’s also been exciting.

“I personally am also pretty amazed every day that I’m just walking around and living on top of this ice sheet. And if I just dug down a little bit, I’ll find these air bubbles that are hundreds of thousands or millions of years old,” he said.

Those air bubbles are like tiny portraits of past atmospheres, Chalif said. Researchers will study them to understand what the climate has been like over the course of Earth’s history.

“There’s no other paleoclimate proxy on Earth that allows us to get in a time machine, go back a million years, and measure what the atmosphere is like a million years ago. It’s really an amazing thing,” Chalif said.

That information could help scientists learn more about future climate change, and how greenhouse gas emissions may affect the atmosphere for years to come.

COLDEX is hoping to learn more about how carbon and methane relate to temperatures over time, among other things, Chalif said.

“I always like to say our best predictions of future climate change are reliant on our best understanding of how the climate system works in general,” he said. “If we don’t understand how we got here and how our climate system works, then we’re going to be limited in what we can say about what’s going to happen in the future.”

The Antarctic ice gathered on this expedition is special not only because it’s so old. It’s also a still-frozen specimen in a quickly warming world.

“One of the interesting and sad things of being an ice core scientist right now is a lot of these sites that we get ice cores from — maybe not in Antarctica yet, but around the world, in Greenland, in mountains — are melting,” he said. “The actual ice core record, this archive of past climate conditions, is either disappearing or being compromised.”

Some of the ice will make its way back to Dartmouth in the coming months, where Chalif will continue to study it — looking at impurities like sea salt, dust, and minerals to understand more about what the ancient frozen water can reveal.

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