Two studies have investigated the canoe-building technologies and climate conditions which allowed early Polynesians to colonise areas such as New Zealand and Easter Island.
Researchers studying the remains of a Polynesian canoe discovered on a western New Zealand beach found a carved sea turtle, rare in Maori art, and evidence of repairs and re-use.
The expansion of the tropics and associated changes in Pacific Ocean wind patterns facilitated the Polynesian migration to the far eastern and southern ends of the Pacific including Easter Island, New Zealand and sub-antarctic Auckland Islands.
Macquarie University’s Associate Professor Ian Goodwin and colleagues reconstructed wind-field patterns from modelled Pacific sea level pressure at 20-year intervals spanning the period 800 AD to 1600 AD.
They revealed climate windows where the most favourable sailing conditions for travel between central East Polynesia and New Zealand occurred between 1140 and 1260 AD, and for travel to Easter Island between 1250 and 1280 AD.
The climate changes accords well with the archaeological evidence that suggests a rapid colonisation of Polynesian islands by sea-faring people, including the colonisation of New Zealand between 1100 and 1300 AD.
Off-wind or down-wind sailing between central East Polynesia and New Zealand was unusually possible during this period, when intensification of the Pacific subtropical anticyclone strengthened trade winds toward New Zealand.
New Zealand was potentially colonised by voyaging from the Tonga/Fiji Islands, the Southern Cook Islands and the Austral Islands further east.
Similarly, the wind patterns revealed that Easter Island might have been colonised from both Central East Polynesia and from Chile.
“This research fits in the Polynesian folklore, which refers to multiple migrations – our mapping of the climate conditions at that time they were travelling confirms the possibility,” said Professor Goodwin.
It also indicates that Polynesian sailing-canoes did not need a capability to sail to windward and that all passages could have been made downwind over the immense ocean tracts.
The research results are published in the journal PNAS (Proceedings of the National Academy of Science).
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