Ice covering Beaufort Sea near the Arctic Ocean typically reaches full-blown breakup by late May each year as air and water temperatures warm, and as daylight turns longer. But 2016 has been dramatically different.

This year, significant breakup and fracturing of the sea ice had occurred by mid-April, as seen in these Landsat 8 images acquired almost exactly a year apart. On April 13, 2015, the ice is largely intact, though fracturing has begun. A year later, on April 15, 2016, much more open water is visible.

Ice specialists with NASA say this year’s breakup is attributable to unusually warm air temperatures during the first months of the year, and to strong winds caused by a stalled high-pressure system over the area. The same warmth that fueled the massive Fort McMurray wildfire in northern Alberta earlier in May is part of the weather pattern affecting the Beaufort Sea.

Though the region was once covered by thicker, multi-year ice, it now has largely seasonal, first-year ice that is thinner, weaker, and more easily broken up by strong winds. While the early breakup hints to the possibility that 2016 could ultimately witness the lowest sea ice extent in the history of satellite recording, that, of course, will depend on the weather conditions in the coming months. Future Landsat acquisitions will help scientists monitor the area and visualize changes.