Caves May Hold Clues to Greenland's Warmer Past

Researchers visited Greenland’s northernmost caves to better reconstruct Earth’s past climates.

Unexplored caves. A harsh, icy terrain. Swarms of animals eager to nibble at human visitors.

Its sounds like the premise of a new science fiction flick. But for Gina Moseley, a National Geographic grantee and cave scientist at Austria’s University of Innsbruck, not only is it science fact, it’s a once-in-a-lifetime opportunity to decode the Earth’s past climate.

“It’s something I’ve wanted to do since I was a Ph.D. student,” says Moseley, who led an expedition earlier this year to the caves surrounding Centrum Sø, a lake on the northeast tip of Greenland. The remote region’s caves are among the most northern that humans have explored, and the rocks inside—which slowly formed by water percolating into or trickling through the cave—contain chemical clues.

By analyzing the rocks’ carbon and oxygen content, Moseley and her team will be able to reconstruct the region’s climate between 200,000 and 500,000 years ago—a warmer, wetter time for northeast Greenland that’s poorly understood by researchers today. “From [these rocks], we could construct a climate record older than the current limit of the Greenland ice core—a completely new time,” says Moseley.

The more detailed record will improve scientists’ predictions for how Earth will respond to human-caused climate change, as well as fill in details on the recent Pleistocene epoch, a two-million-year time period marked by slow fluctuations between warmth and cold.

But to get these rocks, Moseley and four colleagues needed to fly above 80 degrees north, to a barren landscape visited by only a handful of prior geological expeditions—whose presence can still be felt, even today. At one point, Moseley and her colleagues found and even ate canned food left behind by a 1960 expedition to the caves. (Read more about the improbably delicious, 55-year-old rations the team found.)

They also had to contend with the sometimes perilous terrain and the threat of being eaten … by hordes of mosquitoes whose populations have boomed with the rapidly warming climate.

Moseley, however, wouldn’t have it any other way. “Take care of the environment; take care of nature,” she says. “It has a lot to offer, and we have a lot to learn from it.”

In this gallery, we take a look behind the scenes of Moseley’s expedition—and how scientists work in the extreme conditions of some of the world’s northernmost caves.