Surprise Lake Sheds Light on Underbelly of Greenland's Ice

Scientists have been surprised to find water pooling beneath the ice

In a serendipitous discovery, a team of scientists has found a lake at the bottom of the ice where the relatively warm meltwater pools and makes the ice around it slushier. Ultimately, that could make the ice flow faster to the ocean. Credit: NASA/USGS

On a clear day, anyone flying over Greenland on the route between North America and Europe can look down and see the bright bluepatches of melted wateratop the flat, blindingly white expanse ofthe ice sheetthat covers the island, the second largest chunk of ice on Earth.

Scientists have long known this meltwater flows in streams along the ice sheets surface before disappearing down chutes that take it tumbling to the bottom of the ice sheet, where the ice scrapes against bedrock.

It was thought that the water quickly flowed between ice and rock and out to sea, with little impact on the bottom ice layers. But a new study suggests the story isnt so simple. In a serendipitous discovery, a team of scientists has found a lake at the bottom of the ice where the relatively warm meltwater pools and makes the ice around it slushier. Ultimately, that could make the ice flow faster to the ocean.

The finding, detailed in theJan. 22 issue of the journal Nature, suggests that this process could be important to more accurately modeling how Greenland will respond to climate change and contribute to the already 8 inches ofglobal sea level risesince 1900. Greenland holds enough ice to raise global sea levels by 24 feet, and how much and how quickly it melts could change projections offuture sea level rise, which theIntergovernmental Panel on Climate Changeputs between 10 and 32 inches by 2100, including contributions from Greenlands glaciers.

What the heck is that? As happens so often in science,Mike Williswasnt actually looking for what he ended up discovering. The glaciologist was combing through satellite and GPS data to see what small, local effects could be clouding satellite measurements of larger changes in Earths gravity from ice loss.

What he did not expect to find was a hole twice the size of Central Park in a small ice cap in the northern reaches of Greenland.

What the heck is that? he thought when he saw it.

He didnt think he could possibly be the first person to have spotted it. Surely someones noticed a gigantic hole in northern Greenland before, he said, but there were no records of it.

Original post:
Surprise Lake Sheds Light on Underbelly of Greenland's Ice