The Bering Strait should be covered in ice, but it’s nearly all gone
During winter, the Bering Strait has historically been blanketed in ice. But this year, the ice has nearly vanished. “The usually ice-covered Bering Strait is almost completely open water,” Zack Labe, a climate scientist and Ph.D. candidate at the University of California at Irvine, said over email.
At its narrowest point, the Arctic strait between the U.S. and Russia is 55 miles across, and there’s a prominent theory that people once crossed from Asia into North America across an exposed Bering land bridge (back when sea levels were lower).
In modern times, however, this frigid waterway usually builds ice through the winter, reaching its greatest extent in late March.
After that, the ice usually lingers for months. “There should be ice here until May,” Lars Kaleschke, a climate scientist at the Alfred Wegener Institute for Polar and Marine Research, said over email.
There is something significant going on in the Bering Sea: a very low ice extent for the second year in a row. pic.twitter.com/mrSlrT398Z
— Lars Kaleschke (@seaice_de) March 3, 2019
But now, in early March, the ice extent is the lowest in the 40-year satellite record, said Labe. On March 2 specifically, the ice extent was lowest on record for that day of the year, added Kaleschke. Overall, the last two years have now seen exceptionally low ice cover in the Bering Sea, and there are a few reasons why.
In the longer-term, the Arctic is warming over twice as fast as the rest of the globe, leading to significant melting across much of the Arctic, even where the ice is the thickest, oldest, and most resilient.
“The 12 lowest extents in the satellite record have occurred in the last 12 years,” the National Oceanic and Atmospheric Administration’s 2018 Arctic report concluded.
This Arctic warming is especially notable near the Bering Strait. “In the long-term, temperatures in northern Alaska have been rising faster than anywhere else in the United States,” said Labe.