Research project: Late Holocene mega-tsunamis and the coastal archaeological record of New South Wales
- Start date:
For many years it has been argued that the coastlines of Australia, especially those of south and central New South Wales, were inundated repeatedly in the Holocene by large tsunamis up to 80 m high (called mega-tsunamis). It was claimed that the impact of these mega-tsunamis meant coastal Aboriginal camps were abandoned, and that the marine component of the diet of local Aboriginal people changed at the time of the two most recent inferred mega-tsunamis, at or about 500 or 1500 years ago.
Our investigations of the stratigraphic sequences of excavated archaeological sites along the New South Wales south coast show no evidence to support such claims. Changes in shellfish exploitation patterns and adoption of new fishing technologies by Aboriginal people on this coast in the last millennium do not coincide with the times of inferred tsunamis.
In addition, the mean probability distribution of the youngest calibrated radiocarbon ages from 55 dated archaeological sites in three tsunami-susceptibility classes (grouped by site elevation and distance from the shoreline) does not differ from random expectations, and shows no evidence that sites in susceptible locations on the south-central New South Wales coast were permanently abandoned at these times. The mean probability distributions of 108 calibrated radiocarbon ages derived from charcoal sampled from sites in the three susceptibility classes also do not differ from random expectations, and offer little support for the inference that sites were temporarily abandoned in the aftermath of these inferred events.
Dr Val Attenbrow , Principal Research Scientist