Wind pattern re-creations may explain south Pacific settlements

New Scientist : How humans reached remote islands such as Easter Island has been heavily debated. Current wind patterns prevent sailing toward Easter Island and New Zealand from Polynesia without the right equipment to sail against winds. However, Ian Goodwin of Macquarie University in Sydney and Atholl Anderson of the Australian National University in Canberra believe that wind patterns in the Middle Ages may have changed enough to allow the Polynesians to reach those remote places. The researchers examined tree rings, lake sediments, and ice cores to reconstruct climate and wind patterns in the region during the period of Polynesian expansion between 1000 and 1300 CE. The model they created shows that the tropical regions expanded and contracted over a span of decades. A contraction moved westerly winds farther north and created a direct route to Easter Island between 1080 and 1100 CE, the same time period anthropologists believe the island was settled. An expansion between 1140 and 1160 CE shifted easterly winds south, which allowed sailors to reach New Zealand, again during the same period the anthropological record shows the earliest settlements on the islands.