Bering Land Bridge

The present-day floor of the Chukchi and Bering Seas, which emerged as dry land during Late Pleistocene glacial advances. It is the only route for faunal exchange between Eurasia and North America as it united Siberia and Alaska. It seems to have been breached only in the past 2.5 million years, with the earliest immigrants crossing it about 40,000-15,000 years ago. They were part of a migratory wave that later reached as far south as South America (about 10,000 years ago). During the Ice Age the sea level fell by several hundred feet, making the strait into a land bridge between Asia and North America, over which a considerable migration of plants and animals, as well as man, occurred. That period also allowed the transit of cold water currents from the Pacific into the Atlantic.

The present-day floor of the Chukchi and Bering Seas, which emerged as dry land during Late Pleistocene glacial advances. Asian hunters, probably following migrating big game herds, are thought to have entered the Americas by this route. During the most recent major advance (Late Wisconsin) the ice-free bridge was open, to a maximum width of 2000 km, for most of the period 25,000 to 10,000 bp. The weight of the archaeological evidence shows this to be the most likely period for transmigration, although crossing during an earlier advance cannot be completely ruled out.