STOCKHOLM - An island of ice more than four times the size of Manhattan is drifting across the Arctic Ocean after breaking off from a glacier in Greenland.
Potentially in the path of this unstoppable giant are oil platforms and shipping lanes. Any crash could do untold damage. In a worst-case scenario, large chunks could reach the heavily trafficked waters where a Greenland iceberg sank the Titanic in 1912.
It's been a summer of near biblical climatic havoc across the planet, with wildfires, heat, and smog in Russia and killer floods in Asia. But the moment the Petermann Glacier cracked last week - creating the biggest Arctic ice island in half a century - may become the symbol of a warming world. "It's so big that you can't prevent it from drifting. You can't stop it," said Jon-Ove Methlie Hagen, a glaciologist at the University of Oslo in Norway.
Few images can capture the world's climate fears like a 100-square-mile chunk of ice breaking off Greenland's vast ice sheet, a reservoir of freshwater that if it collapsed would raise global sea levels by a devastating 20 feet.
Researchers are scrambling to plot the path of the floating ice shelf. It is moving toward the Nares Strait separating Greenland's northwestern coast and Canada's Ellesmere Island.
If it enters the strait before the winter freeze, due to start next month, it probably will be carried south by ocean currents, hugging Canada's east coast until it enters waters busy with oil activities and shipping off Newfoundland.
"That's where it starts to become dangerous," said Mark Drinkwater of the European Space Agency.
The Canadian Ice Service estimates the journey will take one to two years. The floe is likely to break up as it bumps into other icebergs and jagged islands. The fragments would be further ground down by winds and waves and would start to melt as they move into warmer waters.
"But the fragments may still be quite large," warned Trudy Wohlleben, a Canadian ice forecaster. It's possible to redirect smaller icebergs, by towing them or spraying them with water cannons, but, "I don't think they could do that with an iceberg this large," she said.
Although thousands of icebergs break off Greenland's glaciers and into Arctic waters every year, scientists say this ice island is the biggest in the Northern Hemisphere since 1962.
The retreat of Greenland's glaciers has accelerated in recent years. It is one of the least understood pieces of the climate puzzle. A team of climate scientists who visited the Petermann Glacier last year, expecting it to crack then, plans another trip within weeks.
"We did leave behind a couple of time-lapse cameras and 11 GPS [devices]. Now we are scrambling to get up there and recover the data," said Jason Box, an expert on Greenland glaciers from the Byrd Polar Research Center at Ohio State University.59.33228 18.06284
An island of ice more than four times the size of Manhattan is drifting across the Arctic Ocean after breaking off from a glacier in Greenland.