Almost exactly a year ago, a 251-square-kilometer sheet of ice broke from the Petermann Glacier in Greenland and started slowly drifting into the open ocean. Now, a year later, satellite imagery reveals that the Petermann Ice Island—a Manhattan-size chunk of that ice sheet—is floating in Canadian waters and heading toward the fragmented coastline of Newfoundland.

Gene Patey captured this jarring image of a piece of the towering iceberg looming over the idyllic-looking hamlet of Goose Cove, although NASA's Earth Observatory predicted that the ice island would most likely get grounded on the shallow sea floor before it could strike land. And down the coast from Goose Cove, a Port Hope Simpson crab fisherman captured some footage of a smaller, almost five-kilometer-long chunk of the ice island floating in open waters. Even if the drifting ice doesn't collide anywhere with the shoreline, it still poses a risk to ships and offshore oil rigs.

This isn't the first time ice sheets have calved from the Greenland mainland, but it's one of the largest breaks. In 2010, the average temperature in Nuuk, Greenland's capital, was the warmest ever recorded, and Climatewire reported that "Greenland's ice sheet is [now] melting faster than it has since at least 1958."

—Lauren F. Friedman