E. Kiki Kuijjer (2016)
Keywords: Australasia, Palaeolithic, migration, seafaring, ocean modelling.
The migration by anatomically modern humans (AMH) to Australasia around 50,000 years ago can be regarded as the first true hominin migration rather than a dispersal, because open water had to be crossed between Sunda (Southeast Asia) and Sahul (Australasia). The archaeological record of early settlement is limited, but evidence suggests short crossings from Southeast Asia to Papua New Guinea and northern Australia at a time when sea levels reached c. 80 m lower than today.
Although the maritime environment is central to the migration to Australasia, the nature of the colonisation process (whether it entailed deliberate seafaring or unintentional drift, and what this can imply about AMH behaviour) is still poorly understood. To resolve this, it is crucial to understand the environmental conditions that influenced dispersal.
Here, dynamical effects of the maritime environment on seafaring are addressed with computer models of ocean circulation and novel drift calculations. To demonstrate this method, a particle-tracking algorithm is used with high-resolution ocean model current data to explore modern-day ocean drift between Southeast Asia and Australasia. Large ensembles of simulated drifts are calculated and further analysed to determine the most probable timescale and trajectory of drift between coastal departure and arrival points. These will be assessed against observations of drifting buoy trajectories. The tracking algorithm will be further developed to account for the “windage” effects of prevailing winds on a drifting body. Ultimately, this approach will be applied to ocean currents in regional simulations for different time-slices within the period of early migration.