Pacific Migrations.

At http://phys.org/print396594959.html … modelling and statistical data have been used to explore how the colonisation of the Pacific islands took place and what role wind systems might have in the process. It was shown that Hawaii and New Zealand may have been found as a result of La Nina conditions existing in the Pacific whereas colonisation eastwards, they think, was a result of El Nino conditions. The problem with this study is obvious – they have limited their modelling to known wind systems and weather changes that occur in the modern world. The situation could have differed in the not so recent past. One pointer comes from the archaeology in that it shows there were surges in movements between 3400 and 3100BC, and again between 900 and 1200AD. Is it just a coincidence that the former coincides with the warm climate conditions of the Bronze Age and the latter with the Medieval Warm Period. This would tend to indicate that migration peaked during periods of warmth – and over population was the root cause. Presumably El Nino conditions were in dominance during the warmer spells of climate – hence the impetus to push eastwards. What the study does not explain is why there was a 2000 year period of low migration activity. Could population numbers have plunged at the end of the  Bronze Age?