Ice extent in Bering Sea at lowest levels in 5,500 years
A recent analysis has shown that winter ice in the Bering Sea, in the north Pacific Ocean between Alaska and Russia, is at its lowest level in the past 5,500 years.
Researchers studied vegetation that has been growing for the last five centuries on the uninhabited island of Saint Matthew.
They studied variations in peat layers of oxygen atoms called isotopes 16 and 18, whose concentrations over time correspond with shifts and precipitation in atmospheric and oceanic conditions.
“It’s a small island in the middle of the Bering Sea, and it’s essentially been recording what’s happening in the ocean and atmosphere around it,” said Miriam Jones, the researcher from University of Alaska.
The Arctic and Bering Seas ice melts in summer and is frozen again in winter, but satellite observations date back only to 1979.
For the Arctic, in recent decades, the reduction of winter ice is clear and rapid, in parallel with global warming and increasing atmospheric concentration of carbon dioxide.
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