Bering Sea Once Warmer, Biologically Productive

The Bering Sea, a frigid strip of ocean between Alaska and Russia, was once the much-warmer home to a rich diversity of life, new research suggests.

Deep sediment cores retrieved from the seafloor indicate that the region was ice-free year-round and very biologically productive during the Pliocene Warm Period, about 3.5 million to 4.5 million years ago.

"Evidence from the Pliocene Warm Period is relevant to studies of current climate change because it was the last time in our Earth's history when global temperatures were higher than today," said Christina Ravelo, a professor of ocean sciences at the University of California, Santa Cruz. Ravelo presented the new findings today (Dec. 13) in a talk at the 2010 fall meeting of the American Geophysical Union (AGU) in San Francisco.