Massive sections of ice (center front) have broken away from the Jakobshavn glacier into the sea. There's enough water stored in Greenland's glaciers to raise the sea level by 20 feet.
Massive sections of ice (center front) have broken away from the Jakobshavn glacier into the sea. There's enough water stored in Greenland's glaciers to raise the sea level by 20 feet. Ian Joughin/Science/AAAS
The glacier that's blamed for producing the iceberg that sunk the Titanic has been pushing much more ice into the ocean over the past two years, according to a new study published Monday.
Greenland's Jakobshavn glacier is essentially a river of ice that floats in a narrow valley. Over the past decade, it has been flowing faster toward the sea. And that rate has increased rapidly over the past two summers, apparently because the front of the glacier is now sitting in deep water, so there's not much holding it back.
As the glacier crumbles into the sea, the ice has been surging forward at the rate of 150 feet per day, according to a study published in the journal The Cryosphere.
That makes Jakobshavn by far the fastest-moving major glacier in the world, according to Ian Joughin at the University of Washington. Other Greenland glaciers have also started to flow a bit faster in recent years.
"As the glaciers flow faster, they discharge more icebergs to the ocean, and as you pour more ice into the ocean, sea level goes up and the ice sheet goes down," Joughin says. "So the fact that this glacier is flowing so much faster means it's actually making a much bigger contribution to sea level."
Over the past decade, the Jakobshavn glacier has added enough water to raise sea level by a millimeter — about the thickness of a dime.
Add up all the other Greenland glaciers, and the melt rate is currently about 3 inches a century. But Joughin says that rate is increasing as the sea and the air around Greenland warm up.