Modelling pre-historic transoceanic crossings into the Americas

Abstract

A method for simulating vessel movement in an oceanic setting is described and used to provide temporal and spatial constraints to potential pre-historic transoceanic crossings into the Americas. The technique is based on current and wind output from numerical models and on leeway drift estimates from the United States Coast Guard. Simulations were carried out for present day (PD) and last glacial maximum (LGM) wind and current conditions. The fastest crossing time for the PD no-paddling experiments occurs between Australia and New Zealand in 23 days. The fastest transoceanic crossings occur between Central Europe and Iceland/Greenland in 72 days, Japan and North America in 83 days and northern Africa and South America in 91 days. The crossing with the highest probabilities of occurrence under 180 days occurs between southern Africa and South America (13%). This increases to 18% when paddling is allowed. Crossings from northern Africa to South America, from Australia to New Zealand and from New Zealand to South America have probabilities of occurrence ⩾ 5 % . Differences between LGM and PD crossing times and rates of occurrence range between 25% and 30%, indicating that the PD results serve as a rough estimate of LGM crossings. Mid-latitude crossings are of shorter duration and more probable during the LGM.