Changing Tidal Dynamics and the Role of the Marine Environment in the Maritime Migration to Sahul

The marine environment plays a central role in the migration of Homo sapiens to Sahul c. 65,000 years ago. Despite the lower mean sea level at this time, humans must have made a maritime crossing from Sunda to Sahul. While tidal dynamics greatly affect the coastal environment, models of changing paleotidal conditions are frequently missing from reconstructions of coastal landscapes and maritime conditions in the deep past. At present, northern Australia is known for its high tidal range and strong current velocity, but tidal dynamics are sensitive to coastal geometry and water depths that were very different in the past. This paper presents a barotropic hydrodynamic model of the Australian coast to explore how past tidal dynamics would have caused variations in coastal environments north of Australia, and how tidal currents could have affected seafaring. The results indicate profound but complex changes in tidal dynamics along the northern Australian coast throughout the Upper Pleistocene, linked to mean sea level fluctuations, which inform the debate about the peopling of Sahul. This special issue is guest-edited by William Davies (Centre for the Archaeology of Human Origins, University of Southampton) and Philip R. Nigst (Department of Prehistoric and Historical Archaeology, University of Vienna).