Did a changing climate in the tropical South Pacific contribute to the eastward migration and settlement of Polynesia?

Summary

This is an abstract from the "Evolutionary and Ecological Perspectives on Oceanic Archaeology: Papers to Honor the Contributions of Melinda Allen" session, at the 90th annual meeting of the Society for American Archaeology.

The migration of humans into the eastern Pacific was rapid and focused around 900-1250 CE. Although the causes of this rapid migration are likely varied, we put forward new evidence to suggest that a change in the mean state of the tropical south Pacific from a La-Niña like to El-Niño like state around the period of migration, could have created conditions for migrations east. We use a range of sediment archives and hydroclimate proxies located in sites within the centre of migration, to reconstruct climate conditions that were characterised by a drier southwest Pacific and wetter eastern pacific 1000 CE. Reductions in zonal sea surface temperatures associated with these changes suggest a weakening of easterly winds that would favour sailing east. Climate modelling supports our reconstructions and suggest reductions in annual rainfall of approximately 20-30% in the Samoa/Tonga archipelagos. Results from socio-hydrological models of makatea islands, highlight the sensitivity of growing populations to droughts within a drying climate. Using these lines of evidence, we suggest that as populations grew, particularly in Island types sensitive to droughts, people with some knowledge of eastern “Gateway islands”, chose to move east at a time when wetter conditions supported their long-term settlement.

This Resource is Part of the Following Collections

• Society for American Archaeology 90th Annual Meeting, Denver, CO (2025)   •
• Evolutionary and Ecological Perspectives on Oceanic Archaeology: Papers to Honor the Contributions of Melinda Allen

Keywords

Record Identifiers

Abstract Id(s): 51865