In mid-August 2010, the Northwest Passage was almost—but not quite—free of ice. The ice content in the northern route through the passage (through the Western Parry Channel) was very light, but ice remained in McClure (or M’Clure) Strait.
The Moderate Resolution Imaging Spectroradiometer (MODIS) on NASA’s Terra satellite captured this natural-color image on August 17, 2010. Although most of McClure Strait looks perfectly ice-free, immediately west of Prince Patrick Island, a band of sea ice stretches southward across the strait (left edge of the image).
The National Snow and Ice Data Center Sea Ice News and Analysis blog reported that even more ice remained in the southern route (through Amundsen’s Passage) of the Northwest Passage in mid-August 2010. Nevertheless, the ice content in the northern route was not only well below the 1968–2000 average, but also nearly a month ahead of the clearing observed in 2007, when Arctic sea ice set a record low. As of mid-August 2010, however, overall sea ice extent was higher than it had been at the same time of year in 2007.
From the time Europeans discovered the North American continent to the mid-twentieth century, sailors searched for a northwest passage that would connect the Atlantic Ocean (and Europe) to the Pacific Ocean (and Asia). No such passage exists through the continent, but during the summer, a northwest route through the Arctic opens up.