The Beaufort Sea is melting way ahead of schedule.
The sea, which borders Alaska to the north, typically melts during the summer and re-freezes in the winter. But this year, pieces of it began detaching in April, a time when it has historically remained frozen.
Here's what it looked like on April 1, as captured by satellite:
Suomi NPP satellite/NOAA
And then on April 24:
Suomi NPP satellite/NOAA
The ice's expected summer melt typically happens later on in May.
Dramatic sea ice break/melt in #BeaufortSea (4/1 vs. 4/24, #MODIS Terra 1km) nearly a month earlier than normal pic.twitter.com/sWpkVSpiy0
- Zack Labe (@ZLabe) April 25, 2016
For comparison, here's what the same area looked like April 24, 2015, the year with the second-lowest maximum ice extent:
NOAA
Looking even farther back, here's what the same area looked like on April 24, 2014.
NOAA
Since 1979, when satellites started collecting data on when sea ice hit a maximum, it has declined by about 10%.