Academy Scientist Discovers Evidence
For Early Opening of Bering Strait

SAN FRANCISCO (January 12, 1999) Ė Braving encounters with grizzly bears, one-hundred mile per hour winds and dense fog shrouding featureless tundra, Academy paleontologist and adjunct curator Louie Marincovich explored the rugged terrain of the Alaska Peninsula in the hope of finding fossils that would reveal the geological age of the first opening of Bering Strait, the seaway that separates Russia and Alaska. Marincovich and two Russian paleontologists, a team previously prohibited by Cold War politics, unexpectedly discovered diatoms (single-celled plants) embedded in fossil marine mollusks. The mollusk species are the signal the Strait was open because it is known that they evolved in the Arctic Ocean and could have entered the Pacific only if Bering Strait was open. By matching the diatom species found in the fossil mollusks with diatoms found in deep-sea ocean cores, Marincovichís research team has determined the time when the land between Siberia and Alaska foundered and allowed marine creatures to migrate between the Arctic and North Pacific oceans for the first time in one hundred million years. Preliminary analysis of the diatoms suggests that Bering Strait opened 4.8 to 5.5 million years ago.

Precisely dating the opening of Bering Strait will conclude the scientific quest to determine the opening dates of all Pacific Ocean gateways or seaways that connect the oceans. Determining the geological time at which gateways opened or closed provides insights into questions about global oceanic and atmospheric circulation patterns. This knowledge helps scientists predict future global climatic changes. "Itís great to finally date this geological event which Russians and Americans have tried to do for decades, and itís especially fitting that the accomplishment was done by Russians and Americans working together," Marincovich commented.

Dr. Marincovichís research is funded by a grant to the Academy of Sciences from the National Science Foundation. His findings will be published in the scientific journal Nature on Thursday, January 14.