Permanent Arctic Ice Nearly Gone

In late August 2009, ice clogged some but not all of the Northwest Passage, and snow had retreated from most of the islands in the Canadian Arctic Archipelago. The Moderate Resolution Imaging Spectroradiometer (MODIS) on NASA’s Aqua satellite caught this rare cloud-free view of the archipelago on August 27, 2009. Credit: NASA

Vast sheets of ice up to 260 feet (80 meters) thick have throughout modern history blocked ships seeking a short cut through the fabled Northwest Passage from the Atlantic to the Pacific. But that ice, known as multiyear ice because it has not traditionally melted during summer like seasonal ice does, is nearly history, Reuters reports.

"We are almost out of multiyear sea ice in the Northern Hemisphere," David Barber, Canada's Research Chair in Arctic System Science at the University of Manitoba. Barber led a mission searching for multiyear ice and instead found a lot of "rotten ice," or thin layers that was "easy to navigate through."

Arctic sea ice has been melting at rapid rates in the last decade. The summer minimum ice area in the Arctic has been far below the 1979-2000 average in recent years.

The Northwest Passage opened in 2007 during a record low for Arctic Ice. Last summer resulted in the second lowest sea-ice extent.

Recent studies have predicted that the Arctic could be essentially ice-free during summer within 30 years, due to a warming planet. Most recently, Peter Wadhams, head of the polar ocean physics group at Britain's Cambridge University, said: "In about 10 years, the Arctic ice will be considered as open sea."