New Evidence for the Pacific Coastal Migration Theory

A new study of soil sediment cores on the Aleutian island of Sanak lends support to the Pacific Coast Migration Model of the original colonization of the American continents.

Map of the Pacific Rim showing the locations of Sanak Island and Monte Verde. Base map by NordNordWest

In the 1970s, archaeologist Knut Fladmark argued that one overlooked pathway into the Americas was along the Pacific coast, following up along the Pacific Rim from Asia, along the coastal edges of the the now-submerged landmass of Beringia and down along the Alaskan and Canadian coast. Called the Pacific Coast Migration Model, the theory came to new attention in the late twentieth century, as more and more evidence of early sites along coastlines became apparent.

But there was still a hitch: the earliest sites in the New World were in South America's coastlines, dated around 15,000 years ago and located tens of thousands of miles south of the Bering Strait. Evidence seemed to show that ice blocked the passageway from Beringia to the coasts of America until 15,000 years ago: that didn't compute.

Published yesterday in Quaternary Science Reviews, however, is evidence in the form of pollen and charcoal from soil cores in deep water within three lakes on Sanak Island in the Aleutians, which suggests that Sanak (and perhaps the corridor into the American continents) was ice free by 17,000 years ago.

• Pacific Coast Migration Model, including details of the research
• Guide to the Population of the Americas
• Monte Verde photo essay

Misarti N, Finney BP, Jordan JW, Maschner HDG, Addison JA, Shapley MD, Krumhardt A, and Beget JE. 2012. Early retreat of the Alaska Peninsula Glacier Complex and the implications for coastal migrations of First Americans. Quaternary Science Reviews 48(0):1-6.