Two US scientists believe they have discovered the actual path the melting Greenland ice takes as it flows into the sea.
Ian Joughin and Sarah Das, from the Woods Hole Oceanographic Institution are currently studying the melting phenomenon that has raised concerns worldwide.
The story of sliding ice starts dozens of miles inland. In summer, some of the ice there melts and forms lakes. Most of those lakes drain thorough mysterious passages called moulins, which carry the water to the bedrock below the ice. Once the water gets under the ice, it lubricates the ice sheet, and the whole sheet flows faster toward the sea.
It is that mysterious passage the duo believe they have discovered and that would help study the pace of the melting.
"My guess is that [the water is] going to the bottom of the ice sheet. Right before it disappears from view, it takes some huge jumps down, and as far as we've dared to creep to the edge and look down, you see it cascading almost 45 degrees or even steeper downwards into the ice with this thundering roar," Das says.
"It is quite an exciting discovery," Das says.
Eighty percent of Greenland is covered with one enormous ice sheet, and it oozes off the edges of the island as so-called outlet glaciers. Among the biggest is the Jakobshavn glacier, on the island's west coast.
It's a sight to behold. Huge mountains of ice — icebergs — clog a narrow fjord and slowly but surely push their way out toward the open ocean.
Scientist Ian Joughin says that in the past few years, Jakobshavn's speed has doubled.
"That's putting about twice as much ice into the fjord as a decade ago ... and twice as much into the ocean," he says.
Joughin adds that Jakobshavn is by no means alone.
"Many of the glaciers, especially along the southeast coast of Greenland, are doing very similar things, and what's kind of scary is that they all started doing them roughly at the same time," he says.
That speed-up was triggered by a spell of unusually warm weather — and that has raised alarms about Greenland. Before the warm-up and speed-up, scientists had thought Greenland's ice would be around for at least a thousand years. Now they are not so sure.
Greenland's ice sheet deforms constantly, like pancake batter flowing on a griddle. Each year, more snow piles up in the middle, and each year, more ice slides off into the sea or melts away. At the moment, Greenland's melt water increases global sea level by about a quarter of an inch per decade. If that melt increases as the world warms, a melting Greenland will eventually eat away the shorelines of the world.
If the Greenland ice cap were to melt tomorrow, the sea level around the world would rise by more than 20 feet.
Things are not that bad at the moment, but could get worse as the global warming rate picks up.
That is some sobering thought as the new year dawns.