Greenland's giant island of ice could pose threat to offshore platforms, shipping

This satellite image provided by NASA and taken on July 5, 2003 shows the Petermann Glacier in Northern Greenland. A giant ice island broke off the Petermann Glacier on Thursday Aug. 5, 2010. A University of Delaware researcher says the floating ice sheet covers 100 square miles (260 sq. kilometers) _ more than four times the size of New York's Manhattan Island. (NASA)

It's slowly drifting across Arctic waters, an iceberg four times the size of Manhattan and reaching nearly 600 feet in depth, that broke off from a glacier in Greenland over the weekend.

Potentially in the path of this unstoppable giant are oil platforms and shipping lanes — and any collision could do untold damage. In a worst case scenario, large chunks of it could reach the heavily trafficked waters where another Greenlandic iceberg sank the Titanic in 1912.

It's been a summer of near Biblical climatic havoc across the planet, with wildfires raging in Russia and floods claiming lives across Asia. But the moment the Petermann glacier cracked — giving birth to the biggest Arctic ice island in half-century — may symbolize a warming world like no other.

"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.

The chunk of ice that has fallen off the Petermann Glacier, is the largest iceberg recorded in over 50 years. The size and structure of the iceberg is a rare occurrence and reflects the oceans warming trends. An estimated 5.5 trillion tons of ice has been set afloat during this event.

Scientists predict it will take nearly two years for the Ice Island to reach the Atlantic by which time, it will in all probability, have broken off into smaller chunks, or have become landlocked elsewhere.

Few images can capture the world's climate fears like a 100 square mile (260 sq. kilometer) 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 (6 meters).

The world's newest ice island also evokes two terrors that have lodged into the collective imagination: The old one of the Titanic and, in

An iceberg similar to this one sunk the Titanic in 1912

endangering oil rigs in its path, the new one of the Gulf oil spill.

Already it is being used as a powerful emblem in the global warming debate: One Massachusetts Congressman has suggested, with presumed sarcasm, that it serve as a home for climate skeptics.

Researchers are in a scramble to plot the trajectory of the floating ice shelf, which is drifting toward the Nares Strait separating Greenland's northwestern coast and Canada's Ellsemere Island.

If it makes it into the strait before the winter freeze — due to start next month — it would likely be carried south by ocean currents, hugging Canada's east coast until it enters waters busy with oil exploration 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. It's 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 start to melt as it moves into warmer waters.

"But the fragments may still be quite large," warned Trudy Wohlleben, a Canadian ice forecaster who first spotted the massive chunk of ice on satellite images on Aug. 5.

Large enough to threaten Canada's offshore platforms in the Grand Banks off Newfoundland. Wohlleben said iceberg control companies can redirect smaller icebergs, by towing them or spraying them with water cannons.

"I don't think they could do with an iceberg that large," she said. "They would have to physically move the rig."

Petermann Iceberg which produced iceberg

Greenland's glaciers pump out thousands of icebergs into Arctic waters every year, but scientists say this is the biggest in the northern hemisphere since 1962.

It stores enough freshwater to keep the Hudson River flowing for more than two years, said Andreas Muenchow of the University of Delaware.

The ice shelf is likely to remain at the heart of the global warming discussion during its lonely journey. Though the link to climate change is unclear, the unusual event coincides with worrisome signs of warming the Arctic.

Since 1970, temperatures have risen more than 2.5 C (4.5 F) in much of the Arctic, much faster than the global average. In June the Arctic sea ice cover was at the lowest level for that month since records began in 1979, according to the National Oceanic and Atmospheric Administration.

The behavior of Greenland's glaciers, which have accelerated in recent years, 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, is now planning another trip within weeks.

"We did leave behind a couple of time lapse cameras and 11 GPS (units). 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.

Box and two British researchers traveled to the glacier last year with Greenpeace activists who offered space aboard their ship, the Arctic Sunrise (above right), to scientists studying climate change.

They were hoping to capture the event with cameras rolling, which would have been a powerful image just months before the Copenhagen climate talks that failed to produce a binding treaty to reduce heat-trapping gas emissions.

"It would have been nice if it had broken off last year," said Melanie Duchin, who led that Greenpeace expedition. "I mean ice melting, it doesn't get any simpler than that."

Still, she finds it ironic that the Petermann breakup happened to the backdrop of a catastrophe linked to fossil fuels. The Arctic Sunrise is now in the Gulf of Mexico, surveying the massive oil spill from the Deepwater Horizon blowout.

Source:
Winnipeg Press, "Greenland's giant island of ice could pose threat to offshore platforms, shipping", accessed August 10, 2010
YouTube, "Icebergs Melting and Calving", accessed August 11, 2010