Palaeoenvironmental records from the now-submerged Bering Land Bridge (BLB) covering the Last Glacial Maximum (LGM) to the present are needed to document changing environments and connections with the dispersal of humans into North America. Moreover, terrestrially based records of environmental changes are needed in close proximity to the re-establishment of circulation between Pacific and Atlantic Oceans following the end of the last glaciation to test palaeo-climate models for the high latitudes. We present the first terrestrial temperature and hydrologic reconstructions from the LGM to the present from the BLB’s south-central margin. We find that the timing of the earliest unequivocal human dispersals into Alaska, based on archaeological evidence, corresponds with a shift to warmer/wetter conditions on the BLB between 14 700 and 13 500 years ago associated with the early Bølling/Allerød interstadial (BA). These environmental changes could have provided the impetus for eastward human dispersal at that time, from Western or central Beringia after a protracted human population standstill. Our data indicate substantial climate-induced environmental changes on the BLB since the LGM, which would potentially have had significant influences on megafaunal and human biogeography in the region.
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Data accessibility. Our data are deposited at the National Science Foundations’ Arctic Data Center and have been uploaded at: https://arcticdata.io/catalog/#view/doi:10.18739/A27N5S. Authors’ contributions. M.J.W., S.B., R.G. and J.W.W. designed the study, M.J.W., E.S.-T., K.C., L.C., K.D., J.K., P.L., R.R., Y.W. and J.W.W. helped prepare samples for analysis, M.J.W., N.B., S.B., J.W.W. and R.G. assisted with field work, E.S.-T., B.A.P., S.B., K.C., L.C., K.D., J.K., P.L., A.M., R.R., Y.W. and J.W.W. collected and analysed the data. All the authors were involved in the interpretation of the results. M.J.W., E.S.-T. and B.A.P. drafted the original manuscript and all the authors were involved in editing and reviewing the manuscript. All the authors gave final approval for publication. Competing interests. The authors declare no competing interests. Funding. Financial support came from the National Science Foundation, Directorate for Geosciences, Office of Polar Programs (grant numbers: PLR-1203772, PLR-1203990, PLR-1204233). Acknowledgements. We thank all the inhabitants of St. Paul Island and in particular Jason Bourdukofski, Bill Briggs, Aquilina Lestenkof, Gary Stanley, Mac Mandregan, Phillip Zavadil, Brenda Jones, Connie Newman, and the National Oceanic and Atmospheric Administration for their hospitality, assistance with site access and field logistics. The Limnological Research Center (LacCore), University of Minnesota, provided facilities for core splitting, imaging, description and sampling. We thank the rest of our field team for their support. We thank Dr. Andrew Henderson and an anonymous reviewer for their constructive suggestions that enhanced our contribution.
© 2018 The Authors.
Copyright 2018 Elsevier B.V., All rights reserved.
- Environmental change
- Stable isotopes
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