SALT LAKE CITY — After nearly a month on Greenland's enormous ice sheet, several scientists returning to Utah say there's increasing evidence of a rapidly warming climate.
And they're trying to figure out whether a mystery deep in the ice is somehow related to the meltdown.
"There's lots of evidence that this part of the world is warming quite dramatically," said professor Kip Solomon of the Department of Geology & Geophysics at the University of Utah.
His team's studies do not involve Greenland's craggy coastline where tongues of enormous glaciers march down to the sea.
As she watched a video captured as the team flew over the fjords and glaciers along the coast, graduate student Olivia Miller said, "That's where all of the icebergs are falling off into the ocean."
The Utah scientists flew inland by helicopter to the vast ice sheet that buries 80 percent of the island. The Greenland ice sheet is 1,500 miles long and nearly 700 miles wide, ranging from 1 to 2 miles deep. The Utah team joined other scientists who lived in tents on the ice while conducting their studies.
"It can be cold and windy," Miller said. "You learn to adapt pretty quickly."
In the video Miller brought back, Solomon can be seen lowering an apparatus down a vertical hole the team bored into the ice sheet.
"I'm sending a probe down there right now to see if there's any water," Solomon said to the camera.
Water inside the ice! That's the central mystery that focused this year's scientific effort. It was discovered five years ago. Why would water exist unfrozen — in one of the coldest places on Earth — deep inside the ice sheet?
"We were shocked," said Rick Forster, a professor in the U. Department of Geography, recalling his team's baffling discovery in 2011. "We pulled an ice-core up and water was just gushing out of it."
In the five years since that discovery they've sent probe after probe down into the ice. They've shot dyes into their bore-holes to see what's going on deep down. They've poured dyes on top to see how water percolates down through the ice sheet.
Essentially they've mapped a water table inside the ice sheet. Between 60 feet and 120 feet below the surface, there's a vast aquifer never observed or even imagined before.
"It's formed this huge reservoir of liquid water," Miller said. "It stays liquid all year round, even throughout the cold winters."
This year's studies lent support to their favorite theory: They suspect that snow on top of the ice-sheet acts like a heavy, warm blanket.
"What seems to be happening," Solomon said, "is that this warming in the summer that melts water and lets that water percolate deep enough is now insulated from the winter cold."
Even if that turns out to be the explanation, some big questions are still on the table.
"I mean, the big question," Miller said, "is how much of this water is going into the ocean."
Is the aquifer inside the ice a symptom of climate change? Or did it develop even before modern-day global warming began? Could water embedded in the ice play a role in speeding up the meltdown and the rising of sea-levels?
"If this water gets to the base of the ice sheet, it could speed up the glaciers and then they would deliver more ice to the oceans which would increase sea-level rise," Solomon said. "So we need to understand it. I don't believe the sky is falling, but we need to understand the role that this mechanism has. We previously just didn't know that this existed."
Their trips to such a harsh place is partly motivated by the pure pursuit of science, but also by a belief that what happens in Greenland could be important to the world.
"We need to know what's going on," Miller said, "and we need to think about how we're going to adapt to it."
The research in Greenland is funded by a grant from the National Science Foundation.